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UBC Theses and Dissertations

Examination of cellulose-lignin relationships within coniferous growth zones Squire, Gordon Balfour 1967

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The University of B r i t i s h Columbia FACULTY OF GRADUATE STUDIES PROGRAMME OF THE FINAL ORAL EXAMINATION FOR THE DEGREE OF DOCTOR OF PHILOSOPHY of GORDON BALFOUR SQUIRE B.S.F., The University of B r i t i s h Columbia, 1961 M.F., Yale University., 1962 THURSDAY, OCTOBER 5, 1967, AT 3:30 P 0M 0 IN ROOM 379, H„R„ MacMILLAN BUILDING COMMITTEE IN CHARGE Chairman: J.R. Adams G„G.S. Dutton E.P. Swan J.A.F. Gardner R.W. Wellwood R.W. Kennedy J.W. Wilson External Examiner: K.Vo Sarkanen Associate Professor, College of Forestry U n i v e r s i t y of Washington, Seattle Research Supervisor: J.W. Wilson EXAMINATION OF CELLULOSE-LIGNIN RELATIONSHIPS WITHIN CONIFEROUS GROWTH ZONES ABSTRACT Quantitative differences i n wood growth zone chemistry were f i r s t reported f o r t y years ago. Several studies have followed, mostly done on wide-ringed material, but always by d i s s e c t i o n into earlywood and latewood segments usually c o l l e c t e d as sizeable samples and analysed by standard or s l i g h t l y modified pro-cedures. An objective of the present work has been to sample and analyze multiple positions within charac-t e r i s t i c coniferous wood growth increments, and thereby search out common patterns r e l a t i n g to wood b i o l o g i c a l a c t i v i t y and product behaviors. Lack of s e l e c t i v e h o l o c e l l u l o s e i s o l a t i o n pro-cedures and the problem of l i m i t e d material have long fr u s t r a t e d attempts to accurately measure and describe carbohydrate patterns within growth zones of coniferous woods. A new approach has been applied to micr-c e l l u l o s e a n a l ysis. This arises from the observation that the corrected y i e l d from n i t r a t i o n of wood pulps and whole woods c l o s e l y matches that obtained as alpha-c e l l u l o s e . It has been shown that O.lg wood-meal sample treated t h i s way in r e p l i c a t i o n s of three provide a determination with s t a t i s t i c a l r e l i a b i l i t y . The pro-cedure was used to examine s i x t y positions within ten increments representing f i v e Canadian coniferous woods of d i f f e r e n t genera. Intra-incremental l i g n i f i c a t i o n patterns were constructed for the same materials by making u l t r a -v i o l e t absorptiometric measurements on products from acetyl bromide - acetic acid digestion of 20 mg wood samples in r e p l i c a t i o n s of three. This follows an t e a r l i e r procedure of this laboratory. The series of alpha-cellulose estimates des-cribed have shown r e l a t i o n s h i p of this long-chain carbohydrate f r a c t i o n to seasonal development within growth zones. New chemical evidence i s provided for a p h y s i o l o g i c a l l y s i g n i f i c a n t phenomenon of some earlywoods. Therein, minimum alph-cellulose y i e l d occurred at considerable c e l l u l a r depth following i n i t i a t i o n of seasonal, growth. It appears that the f i r s t formed earlywood a r i s i n g from "over-wintered" xylary mother c e l l s retains s i m i l a r i t i e s at the chemical l e v e l of organization to l a s t formed tissues of the preceding season, i n contrast to new cambial d i v i s i o n s within a growing season. Both S i t k a and black spruce d i f f e r e d from other woods examined in this regard (Douglas f i r , P a c i f i c s i l v e r f i r and western red cedar) i n that they did not show the phenomenon. Among the ten growth increments studied, the alpha-cellulose estimate. (45.9%.; 1SD = + 2.0%) was the exact complement of l i g n i f i c a t i o n (27„4%; 1SD = + 1.9%) i n each instance. Moreover, combining both values for the s i x t y positions included in the study gave less v a r i a t i o n (73.470; 1SD = 1.2%) than considering either separately. Further evidence for this important r e l a t i o n s h i p was shown by the highly s i g n i f i c a n t (r = 0.785) l i n e a r regression on data combined from a l l increments. This suggests much closer p h y s i o l o g i c a l control over the combina-tion of these chemical e n t i t i e s , than towards the i n d i v i d u a l components involved i n such a system. Residual n i t r o c e l l u l o s e s were used to indicate extent of degradation introduced during preparations. Because of v a r i a b i l i t y i n i n t r i n s i c v i s c o s i t i e s at each p o s i t i o n , however, no consistent trends were found within growth zones. A l i m i t a t i o n of the new micro alpha-cellulose method i s that i t can not be u n i v e r s a l l y applied to a l l woods. Samples from four other species attempted f a i l e d to y i e l d s u i t -able d e r i v a t i v e s . GRADUATE STUDIES F i e l d of Study: Wood and Pulp Science Biometrics . D.. Ormrod Chemistry . G.G.S. Dutton . .. J.B« Farmer L.D. Hayward D.E. McGreer J.R.. S ams S t a t i s t i c s J.H.G. Smith Wood Physical and Chemical Properties J.W. Wilson PUBLICATION Squire, C.B., Swan, E.P. and J.W.Wilson. In press. Intra-increment v a r i a t i o n i n Douglas f i r flavonoids by new technique. Pulp Paper Mag. Can. (scheduled Sept.. 1967 issue) . E X A M I N A T I O N O F C E L L U L O S E - L I G N I N R E L A T I O N S H I P S W I T H I N C O N I F E R O U S G R O W T H Z O N E S b y G o r d o n B a l f o u r S q u i r e B . S . F . U n i v e r s i t y of B r i t i s h C o l u m b i a 1961 M . F . Y a l e U n i v e r s i t y 1962 A T H E S I S S U B M I T T E D I N P A R T I A L F U L F I L L M E N T O F T H E R E Q U I R E M E N T S F O R T H E D E G R E E O F D O C T O R O F P H I L O S O P H Y i n the D e p a r t m e n t of F o r e s t r y We accept this thes i s as c o n f o r m i n g to the r e q u i r e d s t a n d a r d T H E U N I V E R S I T Y O F B R I T I S H C O L U M B I A S e p t e m b e r , 1967 In p r e s e n t i n g t h i s t h e s i s i n p a r t i a l f u l f i l m e n t o f the r e q u i r e m e n t s f o r an advanced deg ree at t he U n i v e r s i t y o f B r i t i s h C o l u m b i a , I ag ree t h a t the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r r e f e r e n c e and s t u d y . I f u r t h e r i agree t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y pu rposes may be g r a n t e d by the Head o f my Department o r by h i s r e p r e s e n -t a t i v e s . I t i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l not be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . Depa r tment The U n i v e r s i t y o f B r i t i s h Co lumb ia Vancouve r 8 , Canada Date Supervisor: Professor J.W. Wilson i i L a c k of a s e l ec t ive h o l o c e l l u l o s e i s o l a t i o n p r o c e d u r e and the p r o b l e m of l i m i t e d m a t e r i a l have l o n g f r u s t r a t e d the attempts of wood sc i en t i s t s to a c c u r a t e l y m e a s u r e and d e s c r i b e c a r b o h y d r a t e y i e lds wi th in con i f erous growth zones . A new m e t h o d has been d e v i s e d for m i c r o - c e l l u l o s e d e t e r m i n a t i o n , Alpha-(o<.) c e l l u l o s e y i e l d m a y b e quant i ta t ive ly e s t i m a t e d as the c o r r e c t e d y i e l d of n i t r a t e d wood m e a l . T h r e e - O . l g wood m e a l s a m p l e s p r o v i d e a s t a t i s t i c a l l y r e l i a b l e d e t e r m i n a t i o n . A m a j o r l i m i t a t i o n of the new technique , however , i s that i t cannot be a p p l i e d to a l l woods . S ix ty pos i t i ons wi th in ten i n c r e m e n t s r e p r e s e n t i n g f ive C a n a d i a n con i f erous woods of d i f ferent g e n e r a w e r e e x a m i n e d and i n t r a - i n c r e m e n t a l pa t t erns w e r e c o n s t r u c t e d . A n o v a and Duncan's test showed la tewood - c e l l u l o s e y i e l d to be g r e a t e r than that of e a r l y w o o d b y a h i g h l y s i g n i -f icant d e g r e e . A l p h a - c e l l u l o s e content throughout m a t u r e growth zones was e s t i m a t e d r e l i a b l y b y l i n e a r c o r r e l a t i o n o r , m o r e a c c u r a t e l y , b y l o g a r i t h m i c t r a n s f o r m a t i o n u s e d i n a r e c e n t m a t h e m a t i c a l m o d e l . T h e s u c c e s s f u l a p p l i c a t i o n of the l a t t er i s i ts f i r s t r e p o r t e d use d e s c r i b i n g the n o n - l i n e a r b e h a v i o r of a wood c h e m i c a l p r o p e r t y a c r o s s a con i f erous i n c r e m e n t . T h e s e pat terns showed r e l a t i o n s h i p of the l o n g - c h a i n c a r b o h y d r a t e f r a c t i o n to s e a s o n a l deve lopment wi th in con i f erous growth zones . In addit ion, s ix of the ten pa t t erns d e m o n s t r a t e d new c h e m i c a l ev idence p e r t a i n i n g to a p h y s i o l o g i c a l l y s ign i f i cant p h e n o m e n o n i n e a r l y w o o d . T h e r e i n , m i n i m u m <s< - c e l l u l o s e y i e l d o c c u r s at c o n s i d e r a b l e c e l l u l a r depth fo l lowing c a m b i a l r e a c t i v a t i o n i n the g r o w i n g season . F i r s t - f o r m e d e a r l y w o o d a p p e a r s to r e t a i n some s i m i l a r i t y at the c h e m i c a l l e v e l of o r g a n i z a t i o n to l a s t - f o r m e d t i s s u e s of the p r e c e d i n g s eason . L a t e r - f o r m e d e a r l y w o o d ( i . e. , f r o m the p r e s e n t year) does not appear to r e t a i n s u c h s i m i l a r i t y . . F r o m e a r l i e r w o r k of this l a b o r a t o r y , l i g n i f i c a t i o n pat terns w e r e d e s c r i b e d for the s a m e m a t e r i a l s , u s i n g u l t r a v i o l e t m e a s u r e m e n t s on a c e t y l b r o m i d e - a c e t i c a c i d d iges t ion p r o d u c t s of two wood m e a l s a m p l e s . E x a m i n a t i o n of o<-ce l lu lose and l i g n i f i c a t i o n pat terns p r o v i d e d ev idence for t h e i r m u t u a l l y e x c l u s i v e b e h a v i o r . F o r the ten i n c r e m e n t s s tudied, the o< - c e l l u l o s e e s t imate (x = 45 .9 + 2.0%) was the exact c o m p l e -ment of l i g n i f i c a t i o n (x = 27. 4+^1. 9%) at a l l pos i t i ons but one. T h e l i n e a r r e g r e s s i o n for data f r o m a l l i n c r e m e n t s was h i g h l y s ign i f i cant ( r = - 0 . 7 8 5 ) . In addi t ion , m i c r o o ( - c e l l u l o s e and m i c r o l i g n i n va lues , when c o m b i n e d , showed a definite t endency to c l u s t e r about a c e n t r a l va lue (x = 73. 4 +_ 1. 2%) suggest ing that c e r t a i n spec ie s r e q u i r e a c o m m o n , c r i t i c a l m e a s u r e of h igh m o l e c u l a r weight m a t e r i a l . D i s p e r s i o n about c o m b i n e d l i g n i n and - c e l l u l o s e e s t imate s was s i g n i f i c a n t l y l e s s than about e i ther of t h e i r i n d i v i d u a l m e a n s . T h i s suggests m u c h c l o s e r p h y s i o l o g i c a l c o n t r o l o v e r the c o m b i n a t i o n of these c h e m i c a l ent i t ies , i n d i c a t i n g that t r e e p h y s i o l o g y i s o r i e n t e d m o r e towards the f i n i s h e d b io synthet ic p r o d u c t than t o w a r d s the i n d i v i d u a l components i n v o l v e d i n such a s y s t e m . I V A s a m e a n s of m e a s u r i n g s u c c e s s f u l n i t r o c e l l u l o s e p r e p a r a t i o n , i n t r i n s i c v i s c o s i t y j^J was u s e d to ind ica te p r e s e n c e o r absence of extens ive d e g r a d a t i o n . B e c a u s e of the h i g h l y v a r i a b l e at each p o s i t i o n tes ted , no cons i s tent t r e n d s i n cha in length w e r e found a c r o s s growth zones . H o w e v e r , i n four i n c r e m e n t s , s ign i f i cant d i f f erences i n jjO throughout the e a r l y w o o d p r o v i d e d fur ther ev idence of two e a r l y w o o d types . V T A B L E O F C O N T E N T S P a g e T I T L E P A G E .' i A B S T R A C T i i T A B L E O F C O N T E N T S v L I S T O F T A B L E S v i i i L I S T O F F I G U R E S x A C K N O W L E D G E M E N T x i I N T R O D U C T I O N 1 L I T E R A T U R E R E V I E W 4 I. H i s t o r y of C h e m i c a l O r g a n i z a t i o n i n W o o d 4 II. V a r i a t i o n s i n C h e m i c a l O r g a n i z a t i o n i n W o o d 8 A . T a x o n o m i c L e v e l 9 B . W o o d Zone L e v e l 13 C . G r o w t h Z o n e and T i s s u e L e v e l 18 D . C e l l W a l l O r g a n i z a t i o n 2 5 E . B i o s y n t h e s i s 29 III. Methods for W o o d M i c r o a n a l y s i s 34 A . C a r b o h y d r a t e F r a c t i o n 34 B . O t h e r Component s 52 M A T E R I A L S A N D M E T H O D S 53 v i P a g e I. W o o d S a m p l e P r e p a r a t i o n 53 A . S a m p l i n g C r i t e r i o n 53 B . P r e p a r a t i o n of W o o d M e a l s 53 C . V a l i d i t y of R e s u l t s 56 II. N i t r a t i o n P r o c e d u r e 58 A . M i x e d A c i d P r e p a r a t i o n 58 B . N i t r a t i o n 60 C . C e l l u l o s e N i t r a t e R e c o v e r y 61 III. N i t r o g e n D e t e r m i n a t i o n 63 I V . V i s c o s i t y D e t e r m i n a t i o n 66 V . L i g n i n D e t e r m i n a t i o n 71 E X P E R I M E N T A L R E S U L T S 73 D I S C U S S I O N 76 I. R e v i e w of D a t a 78 A . A l p h a - c e l l u l o s e E s t i m a t e s 78 B . V i s c o s i t y E s t i m a t e s 80 C . L i g n i n E s t i m a t e s 82 II. I n t r a - i n c r e m e n t A l p h a - c e l l u l o s e E s t i m a t e s and t h e i r S i g n i f i c a n c e 82 A . T w o R e p r e s e n t a t i v e P a t t e r n s 82 B . C h e m i c a l E v i d e n c e for T w o E a r l y w o o d T y p e s . . . . 84 C . A l p h a - c e l l u l o s e P a t t e r n s and E a r l y w o o d - L a t e w o o d V a r i a t i o n s 87 v i i P a g e III. R e l a t i o n s h i p between C e l l u l o s e - L i g n i n P a t t e r n s . . . . 92 A . E v i d e n c e for C o m p l e m e n t a r y C h a r a c t e r 92 B . E v i d e n c e for M u t u a l l y E x c l u s i v e R e l a t i o n s h i p Be tween C e l l u l o s e and L i g n i n 94 C . B i o l o g i c a l In terpre ta t ions 96 I V . R e l a t i o n s h i p s of A l p h a - c e l l u l o s e P a t t e r n s to P h y s i c a l P r o p e r t i e s 100 A . S trength P a r a m e t e r s 100 B . P h y s i c a l E v i d e n c e for Two E a r l y w o o d T y p e s . . . . 101 C O N C L U S I O N S 104 B I B L I O G R A P H Y 107 T A B L E S A N D F I G U R E S 120 A P P E N D I C E S 137 I. R e l a t i o n s h i p between the m a j o r c e l l w a l l components after N o r m a n (94)* 138 II. Sugges ted g e n e r i c c l a s s i f i c a t i o n of wood p o l y s a c c h a * r i d e s after S tewart (117) 139 III. D e s c r i p t i o n of s t e m sect ions and growth i n c r e m e n t s i n c l u d e d i n the study (157). 140 v i i i L I S T O F T A B L E S P a g e T a b l e 1. A n a l y s e s on con i f erous e a r l y w o o d ( E ) , l a tewood ( L ) , and whole wood (W) c a r b o h y d r a t e f r a c t i o n s f r o m the l i t e r a t u r e (based on o v e n - d r y , e x t r a c t i v e - f r e e wood) 121 T a b l e 2. D e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r on oL - c e l l u l o s e y i e l d for 40-60 m e s h Douglas f i r la tewood m e a l u s i n g t h r e e s a m p l e s i z e s ( n i t r o c e l l u l o s e s c o r r e c t e d to 13. 65 + 0. 30% ni trogen) 122 T a b l e 3. D e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r for Douglas f i r l a tewood n i t r o c e l l u l o s e n i t r o g e n content 123 T a b l e 4. S u m m a r y of a l p h a - c e l l u l o s e and l i g n i n e s t imate s and n i t r o c e l l u l o s e v i s c o s i t i e s for ten con i f erous i n c r e m e n t s e x a m i n e d 124 T a b l e 5. L i n e a r r e g r e s s i o n of a l p h a - c e l l u l o s e e s t imate s ( Y , %) • on p o s i t i o n (X) , for a l l spec i e s and i n c r e m e n t s 126 T a b l e 6. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in P i c e a m a r i a n a ( M i l l . ) B . S . P . I n c r e m e n t N o . 34 127 T a b l e 6 A . Duncan ' s tes t of m e a n a l p h a - c e l l u l o s e e s t imate s (%) wi th in P i c e a m a r i a n a ( M i l l . ) B . S . P . I n c r e m e n t N o . 34 127 T a b l e 7. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imates (%) wi th in P icea . . s i t chens i s (Bong.) C a r r . I n c r e m e n t N o . 70 127 T a b l e 7 A . Duncan's test of m e a n a l p h a - c e l l u l o s e e s t imates (%) wi th in P i c e a s i t c h e n s i s (Bong.) C a r r . I n c r e m e n t N o . 70 128 T a b l e 8. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in T h u j a p l i c a t a Donn . Increment M o . U3 128 T a b l e 8 A . Duncan ' s tes t of m e a n a l p h a - c e l l u l o s e e s t imate s (%) wi th in T h u j a p l i c a t a Donn . I n c r e m e n t N o . 73 128 XX P a g e T a b l e 9. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40 128 T a b l e 9 A . Duncan ' s tes t of m e a n a l p h a - c e l l u l o s e e s t i m a t e s (%). w i th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40 129 T a b l e 10. A n a l y s i s o f v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t s N o . 64 to 66 129 T a b l e 10A. Duncan ' s tes t of m e a n a l p h a - c e l l u l o s e e s t i m a t e s (%) wi th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t s N o . 64 to 66 129 T a b l e 11. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in A b i e s a m a b i l i s ( D o u g l . ) F o r b . I n c r e m e n t s N o . 78 to 80 130 T a b l e H A . Duncan ' s tes t of m e a n a l p h a - c e l l u l o s e e s t i m a t e s (%); wi th in A b i e s a m a b i l i s ( D o u g l . ) F o r b . I n c r e m e n t s N « . 78 to 80 130 T a b l e 12. L i n e a r r e g r e s s i o n of l i g n i n ( Y , %) on a l p h a - c e l l u l o s e e s t i m a t e s ( X , %};for a l l spec i e s and i n c r e m e n t s 131 T a b l e 13. C o r r e l a t i o n coef f ic ients (r) for the l i n e a r r e g r e s s i o n of itfj (d l / g) on a l p h a - c e l l u l o s e y i e l d (%) for s i x i n t r a - i n c r e m e n t p o s i t i o n s , showing effect of i n c l u s i o n (+) or e x c l u s i o n (-} of data f r o m P o s i t i o n N o . one (which c o r r e s p o n d s to f i r s t - f o r m e d e a r l y -wood). 132 X L I S T O F F I G U R E S P a g e F i g u r e 1. T w o r e p r e s e n t a t i v e pat terns of a l p h a -c e l l u l o s e (est. ), % 133 F i g u r e 2. T e n pat terns showing a l p h a - c e l l u l o s e ( e s t . ) , %, l i g n i n , %, and t h e i r s u m 134 F i g u r e 3. L i n e a r c o r r e l a t i o n of l i g n i n , %, i n c o m b i n a t i o n wi th a l p h a - c e l l u l o s e (est . ); %, for ten con i f erous i n c r e m e n t s 135 F i g u r e 4. M e a n s (x) and s t a n d a r d deviat ions (s) for a l l a l p h a -c e l l u l o s e and l i g n i n e s t imate s and the ir s u m 136 x i A C K N O W L E D G E M E N T W h i l e p r e p a r a t i o n of any thes i s i s m a i n l y the w o r k of one i n d i v i d u a l , n e v e r t h e l e s s , i t r e p r e s e n t s the c o m b i n e d efforts of a group of peop le . D u r i n g the w r i t i n g of this thes i s , I b e c a m e acute ly aware of the t i m e and e n e r g y that o thers h a d w i l l i n g l y g iven to m e . T h e r e f o r e , i t i s m y d is t inct p l e a s u r e to acknowledge the inva luab le contr ibut ions made b y the fo l lowing p e r s o n s : I w i s h to s ing le out m y s u p e r v i s o r , D r . J . W . W i l s o n , P r o f e s s o r , F a c u l t y of F o r e s t r y , for h is pa t i ence and ded ica t ion to the h ighest p r o f e s s i o n a l s tandards d u r i n g a l l phases of this w o r k and for h is t r u l y enl ightened, i n s p i r i n g guidance and p e r s o n a l c o n c e r n for m y behalf . L i k e w i s e , I w i s h to thank D r . R . W . W e l l w o o d , P r o f e s s o r , F a c u l t y of F o r e s t r y , D r . G . G . S. Dutton, P r o f e s s o r , D e p a r t m e n t of C h e m i s t r y and D r . R . W . K e n n e d y , F o r e s t P r o d u c t s L a b o r a t o r y ( V a n c o u v e r ) , for t h e i r m o s t c o n s t r u c t i v e suggest ions and c r i t i c i s m s ; D r . A . K o z a k , A s s i s t a n t P r o f e s s o r , F a c u l t y of F o r e s t r y , for h i s e v e r - c h e e r f u l a s s i s t a n c e i n s t a t i s t i c a l a n a l y s i s and c o m p u t e r p r o g r a m m i n g ; D r . K . S a r k a n e n , P r o f e s s o r , F a c u l t y of F o r e s t r y , U n i v e r s i t y of Wash ing ton , for s e r v i n g as the E x t e r n a l E x a m i n e r of the thes i s ; M r s . M . L a m b d e n , F a c u l t y of F o r e s t r y , for draf t ing the f i g u r e s ; M r . S r Z . Chow, F o r e s t P r o d u c t s L a b o r a t o r y ( V a n c o u v e r ) , for s a m p l e m a t e r i a l and data; M r . U . R u m m a and M i s s H . A p e l t , T e c h n i c i a n s , for he lp i n the l a b o r a t o r y ; M r . E . T . S q u i r e and M i s s B . P e a r c e y , for p r e p a r a t i o n o f the m a n u s c r i p t ; and the V a n D u s e n F o u n d a t i o n , P u l p and P a p e r R e s e a r c h Institute of C a n a d a , and the U n i v e r s i t y of B r i t i s h C o l u m b i a for f i n a n c i a l a id . 1 I N T R O D U C T I O N W o o d substance m a y be d i v i d e d into t h r e e m a i n c l a s s e s of m a t e r i a l : c e l l w a l l components , extraneous components , and t r e e s e c r e t i o n s . T h e la t t er a r e d i s t i n g u i s h e d b y t h e i r i n s o l u b i l i t y i n c o l d water and s o l u b i l i t y i n n o n - p o l a r n e u t r a l so lvents ; o l e o r e s i n s exuded f r o m con i f erous r e s i n ducts a r e s u c h an e x a m p l e . E x t r a n e o u s components a r e so luble to s o m e degree i n c o l d water and i n n e u t r a l so lvents . H o t water s o l u b i l i t y i s not u s e d to c h a r a c t e r i z e e x t r a c t i v e s s ince this m a y f ree wood ac ids w h i c h can cause h y d r o l y s i s . A l t h o u g h the percentage of extraneous components i n wood m a y be v e r y low, t h e i r inf luence m a y be so g r e a t as to often c h a r a c t e r i z e a wood m o r e s h a r p l y than c e l l w a l l components ; these l a t t er a r e d i s t i n g u i s h e d b y t h e i r i n s o l u b i l i t y i n c o l d water o r n e u t r a l so lvents and b y t h e i r b e i n g an i n t e g r a l p a r t of the c e l l u l a r s t r u c t u r e . T h e y a r e ch ie f ly h igh p o l y m e r s , t y p i c a l e x a m p l e s b e i n g c e l l u l o s e , h e m i c e l l u l o s e s , and l i g n i n s ; p e c t i c m a t e r i a l s and m i n e r a l depos i t s (found ch ie f ly i n the m i d d l e l a m e l l a ) a r e a l so i n c l u d e d . It i s obvious that these def ini t ions a r e l i m i t e d and far f r o m c o m -ple te and, t h e r e f o r e , they await c o n s i d e r a b l e addi t ion and r e f i n e m e n t . In wood s c i e n c e , m a n y u s e f u l and s o p h i s t i c a t e d ana lyse s have been m a d e on c a r b o h y d r a t e f r a c t i o n s of con i f erous s e c o n d a r y x y l a r y t i s s u e s with the e x p r e s s p u r p o s e of f u r t h e r i n g u n d e r s t a n d i n g on such h i g h l y c o m p l e x p r o d u c t s of p lant m e t a b o l i s m . H o w e v e r , the u l t i m a t e i n " p u r i t y " has n e v e r b e e n p r o d u c e d i n h igh y i e l d , p a r t l y b e c a u s e of the l a c k of def in i t ion on what is sought i n the c h e m i c a l s ense . T h i s l a c k of absolute r e f e r e n c e f r o m w h i c h 2 to b a s e ana lyse s causes m u c h confus ion . B e c a u s e c a r b o h y d r a t e s s e p a r a t e d f r o m wood show di f ferent c h e m i c a l and p h y s i c a l p r o p e r t i e s dependent on i s o l a t i o n method , c o m p a r i s o n of a n a l y t i c a l va lues i s confounded to the point w h e r e s u c h c a r b o h y d r a t e f r a c t i o n s on ly have m e a n i n g when r e p o r t e d i n t e r m s of the i s o l a t i o n m e t h o d . N e v e r t h e l e s s , m u c h u s e f u l i n f o r m a t i o n m a y be obta ined through e x a m i n a t i o n of c e r t a i n w e l l - d e f i n e d por t ions i n the c e l l w a l l s . In r e l a t i o n to qua l i ta t ive and quanti tat ive v a r i a t i o n s wi th in the t r e e s t e m , however , c a r b o h y d r a t e f r a c t i o n s have not been e x a m i n e d w i d e l y . F o r i n s t a n c e , l i t t l e i s known r e g a r d i n g the p a t t e r n of h o l o c e l l u l o s e depos i t i on throughout growth i n c r e m e n t s of con i f erous woods . T h i s has r e s u l t e d f r o m the p r o b l e m of s a m p l i n g , w h e r e the tota l amount of m a t e r i a l needed exceeds that w h i c h i s a v a i l a b l e . M o r e i m p o r t a n t , no m e t h o d has b e e n a v a i l a b l e for r e l i a b l y r e p o r t i n g m e a s u r e m e n t of any h o l o c e l l u l o s e , or p o r t i o n thereof , at m a n y points w i th in an i n c r e m e n t . A t mos t , on ly two t i s s u e s ( e a r l y w o o d and latewood) have b e e n s e p a r a t e d and a n a l y z e d . T h e i m m e d i a t e goals of this thes i s w e r e c l o s e l y r e l a t e d to this " a r e a of i n v e s t i g a t i o n . A r e l i a b l e m e t h o d h a d to be d e v e l o p e d for e s t i m a t i n g h o l o c e l l u l o s e , or a constant p o r t i o n thereof , i n con i f erous s e c o n d a r y x y l a r y t i s s u e s , i . e. , wood. A t any l e v e l of s a m p l e s i ze , a c c u r a t e m e a s u r e m e n t of h o l o c e l l u l o s e i s d i f f icul t , hence , i t r e q u i r e s adequate r e p l i c a t i o n . A m o n g the m o r e i m p o r t a n t c o n s i d e r a t i o n s affect ing r e p l i c a t i o n w e r e p a r t i c l e s i z e , e x t r a c t i o n so lvents and t h e i r sequence , and l i m i t e d s a m p l e s i z e . Since o n l y s m a l l amounts of m a t e r i a l w e r e ava i lab le , another r e q u i r e m e n t of the m e t h o d was that i t be of s e m i - m i c r o na ture and give s t a t i s t i c a l r e l i a b i l i t y with a r e a s o n a b l e r e p l i c a t i o n n u m b e r . T h e m e t h o d wou ld be a p p l i e d to m a t e r i a l s a m p l e d wi th in s e v e r a l annual growth i n c r e m e n t s to d e t e r m i n e ac tua l pa t t erns of c e l l u l o s e depos i t i on . A l p h a - c e l l u l o s e pat terns d e t e r m i n e d on wood m a t e r i a l s would be c o m p a r e d to l i g n i n pat terns and, a long with these n e w l y e s t a b l i s h e d pa t t erns , c o m p a r i s o n s wou ld be m a d e with the hope that i n f o r m a t i o n d e r i v e d t h e r e f r o m m i g h t give new ins ight to i n t e r - r e l a t i o n s h i p s between the m a j o r s e c o n d a r y x y l a r y c e l l w a l l c o m -ponents . T h i s c o m p a r i s o n would u p h o l d or refute the hypothes i s e x a m i n e d b y this thes i s w h i c h i s : that l i g n i f i c a t i o n a c r o s s c o n i f e r o u s growth i n c r e -ments is the c o m p l e m e n t to the l o n g - c h a i n c e l l u l o s i c f r a c t i o n of h o l o c e l l u l o i . e. , a l p h a - c e l l u l o s e . 4 L I T E R A T U R E R E V I E W I. H i s t o r y of C h e m i c a l O r g a n i z a t i o n i n W o o d Due to the c o m p l e x n a t u r e of wood, the h i s t o r y and n o m e n c l a t u r e of wood c h e m i s t r y and i ts n o m e n c l a t u r e have often b e e n confused; n e v e r t h e -l e s s , this i s to be expected w h e r e v e r a new b r a n j ^ h of s c i e n c e e m e r g e s . In spite of s h o r t c o m i n g s , i m p o r t a n t d i v i s i o n s and deve lopments have b e e n m a d e i n wood c h e m i s t r y , m a i n l y b y its p i o n e e r s . P u r v e s (97) has r e v i e w e d the h i s t o r y of o r g a n i z e d c e l l u l o s e c h e m i s t r y . T h i s r e a l l y b e g a n i n 1837 wi th P a y e n , al though G a y L u s s a c i n 1811 h a d shown that wood conta ined the e l ements c a r b o n , h y d r o g e n , and oxygen. P a y e n b r o u g h t a s y s t e m a t i c a p p r o a c h to wood a n a l y s i s w h e r e b y he t r e a t e d oak a l t e r n a t e l y with n i t r i c a c i d and a l k a l i to get "ce l lu lose 1 1 , a s o l i d s k e l e t a l substance , w h i c h he d e s c r i b e d as m e c h a n i c a l l y e m b e d d e d i n an " e n c r u s t i n g " subs tance . C h l o r i n a t i o n was u s e d to p r o c u r e the s a m e r e s u l t s with f i r , a c o n i f e r o u s wood . P a y e n ' s w o r k extended o v e r a f ive y e a r p e r i o d and f r o m it , he e s t a b l i s h e d an e m p i r i c a l f o r m u l a for c e l l u l o s e ( C , H 1 r . O ) : , o ID 5 n showed this to be i s o m e r i c with s t a r c h , and b e c a u s e of i ts l a c k of r e s p o n s e to c o l o r i m e t r i c d e t e r m i n a t i o n s , m a i n t a i n e d that c e l l u l o s e was not l i n k e d to the " e n c r u s t i n g " subs tance . F u r t h e r m o r e , P a y e n was c o n v i n c e d of the c h e m i c a l u n i f o r m i t y of c e l l u l o s e . Some botanis ts soon d i sputed this c l a i m , h owever , on the b a s i s that d i f ferent p lant t i s sues v a r i e d w i d e l y i n s ta in ing r e a c t i o n s and c u p r a m m o n i u m s o l u b i l i t y . In 1859, F r e m y m a i n t a i n e d the c e l l w a l l to be c o m p o s e d of s e v e r a l substances ( l i gn in , 5 e n c r u s t i n g substance , and ce l lu lose ) w h i c h he c a l l e d "vascu lose" , "meta", " p a r a " , and r e m a i n i n g c e l l u l o s e s . T h e s a m e y e a r , P e l o u z e showed that, on r e g e n e r a t i o n f r o m c u p r a m m o n i u m solut ion, c e l l u l o s e o r i g i n a l l y d i s s o l v e d i n cone h y d r o c h l o r i c a c i d was now so luble i n a m u c h weaker a c i d . F r e m y ' s contentions w e r e supported 25 y e a r s l a t e r , when c e l l u l o s e h y d r o l y z a t e s w e r e found to conta in ga lac tose , a r a b i n o s e , m a n n o s e , x y l o s e , as w e l l as g lucose; a c c o r d i n g to N o r m a n (94), S c h u l z e noted i n 1891 that the p o l y s a c c h a r i d e s y i e l d i n g these n o n - g l u c o s e s u g a r s w e r e m o r e r e a d i l y h y d r o l y z e d or a l k a l i -ex tractab le j hence , he c a l l e d t h e m h e m i c e l l u l o s e s . T h e m o r e r e s i s t a n t p o l y -s a c c h a r i d e const i tuent r e m a i n e d as c e l l u l o s e . D i f f eren t ia t i on between the two const i tuents , however , l a c k e d s p e c i f i c i t y b e c a u s e d r a s t i c e x t r a c t i o n t r e a t -ments f a i l e d to r e m o v e a l l h e m i c e l l u l o s e s (97). T h e n o n - c e l l u l o s e p o r t i o n of s o l v e n t - e x t r a c t e d plant t i s sue i n c l u d e d h e m i c e l l u l o s e as w e l l as P a y e n ' s e n c r u s t i n g substance and, as these components b e c a m e r e c o g n i z e d as d i s t inc t ent i t ies , the t e r m l i g n i n ( F r e m y ' s "vasculose") denoted the n o n -c a r b o h y d r a t e f r a c t i o n of the n o n - c e l l u l o s i c i n c r u s t a n t s . Such a c l a r i f i c a t i o n i n ideas and n o m e n c l a t u r e d id m u c h to exp la in the r e a s o n s w h e r e b y F r e m y and h i s co l l eagues den ied the c h e m i c a l u n i f o r m i t y of c e l l u l o s e . A s the i s o l a t i o n of c e l l u l o s e r e q u i r e d u s e of h a r s h reagents , i t s e e m e d p l a u s i b l e to accept c e l l u l o s e as an a r t i f a c t p r o d u c e d b y c h e m i c a l change d u r i n g i s o l a t i o n . P u r v e s (97) r e p o r t s that E r d m a n n took this v iew i n 1867, when he c o n s i d e r e d the c o n c r e t i o n s f r o m fru i twood to be " g l u c o -drupose" ( C H , / 0 - ,), whi le s p r u c e wood was " g l y c o l i g n o s e t ! ( C _ n H . , 0 ). 6 M i l d a c i d h y d r o l y s i s left "drupose" , ( C 1 0 r l 0 o ) and "l ignose" ( C ^ H ^ O , , ) , 12 20 o l o 2o 11 and subsequent n i t r i c a c i d e x t r a c t i o n left a n e a r l y constant y i e l d of wood f i b r e (97). E r d m a n n ' s v iews r e c e i v e d suppor t f r o m C r o s s and B e v a n (33), who c l a i m e d that b a s t f i b r e s w e r e u n i f o r m i n c h e m i c a l r e a c t i o n s , and b e l i e v e d that a l l p lant components m e r g e d into one another b y " insens ib le c h e m i c a l g r a d a t i o n s . " C e l l u l o s e , they stated,, was m e r e l y the aggregate r e s u l t i n g f r o m a c h e m i c a l b r e a k d o w n of p lant t i s s u e c a r r i e d to the point w h e r e r e a c t i o n s g e n e r a l l y a c c e p t e d for p u r e c e l l u l o s e w e r e obta ined . T h e i r " l i g n o c e l l u l o s e " t h e o r y was re fu ted i n 1920 when H e r z o g and Janke showed that l i g n i f i e d n o n - w o o d y f i b r e s o r cotton gave an X - r a y p a t t e r n n e a r l y i d e n t i c a l to that of de l i gn i f i ed wood p u l p . T h u s , a u n i f o r m l y o r d e r e d c r y s t a l l i n e l a t t i c e c o u l d be i n u n i f o r m c h e m i c a l c o m b i n a t i o n with l a r g e a m o r p h o u s m o l e c u l e s of l i g n i n , fat, o r h e m i c e l l u l o s e . A c c o r d i n g to M a r k (86), the f r inge m i c e l l a r theory , as f i r s t sugges ted b y N a e g e l e i n 1858, r e n d e r s the concept of ' l i g n o c e l l u l o s e " (and i ts a s s o c i a t e d n o m e n c l a t u r e ) obso le te . N e v e r t h e l e s s h i s t o r i c a l c o n t r o v e r s i e s about the def in i t ion of c e l l u l o s e have as yet not been adequate ly r e s o l v e d . In text i l e o r b o t a n i c a l c i r c l e s , c e l l u l o s e m e a n s the n a t u r a l , c a r b o h y d r a t e p o l y m e r c o l l e c t e d i n f ibrous f o r m that i s the s t r u c t u r a l aggregate of the c e l l w a l l . A s such , it u s u a l l y i n c l u d e s a h e m i c e l l u l o s e f r a c t i o n y i e l d i n g on h y d r o l y s i s s u g a r s other than g lucose (94). A n a l t e r n a t i v e def in i t ion has b e e n adopted b y those s tudying c h e m i c a l s t r u c t u r e , w h i c h fo l lows P a y e n and Schu l t ze i n accep t ing cotton as a s t a n d a r d , r e s t r i c t i n g the t e r m c e l l u l o s e to that p o r t i o n of the c e l l w a l l d e r i v e d e x c l u s i v e l y f r o m g lucose 7 and r e s e m b l i n g cotton c e l l u l o s e i n i t s p h y s i c a l and c h e m i c a l p r o p e r t i e s . T h e f i r s t v iew of c e l l u l o s e i s h e l d b y N o r m a n (94), who def ined h o l o c e l -l u l o s e b y the c h l o r i t e m e t h o d of J a y m e as m o d i f i e d b y W i s e et a l . (153) and d i f f erent ia ted this b y s o l u b i l i t y c r i t e r i a w h i c h , quite expectedly , l e a d to o v e r -l a p p i n g of c a t e g o r i e s and c o n t r i b u t e d to a r a t h e r confused u n d e r s t a n d i n g of wood c h e m i s t r y . T h i s s y s t e m i s p r e s e n t e d as A p p e n d i x I; dotted l i n e s show indef in i te b o u n d a r i e s w h i c h m a y shift a c r o s s this a r e a depending on i n t e n s i t y and n u m b e r of e x t r a c t i o n t r e a t m e n t s . F o r e x a m p l e , s e p a r a t i o n of the h e m i -c e l l u l o s e s into c e l l u l o s a n s and p o l y u r o n i d e h e m i c e l l u l o s e s r e s t s p r i m a r i l y on the C r o s s and B e v a n c e l l u l o s e method; s ince this u t i l i z e s v i s u a l d e t e r m i n a t i o n of r e s i d u a l l i g n i n , the s a m e degree of d e l i g n i f i c a t i o n w i l l r a r e l y be a g r e e d upon b y any two w o r k e r s and, concomi tant ly , r a r e l y w i l l the s a m e ra t io be at ta ined between h e m i c e l l u l o s e s . M o r e o v e r , whi le c h l o r i t e de l i gn i f i ca t ion affects c e l l u l o s a n s and c e l l u l o s e v e r y l i t t l e , the e n c r u s t i n g p o l y u r o n i d e h e m i c e l l u l o s e f r a c t i o n is r e n d e r e d d i s t i n c t l y m o r e so luble , with the r e s u l t that v a r i a b l e amounts w i l l be obta ined, depending on i s o l a t i o n technique . T h e n o m e n c l a t u r e i t s e l f i s m i s l e a d i n g . T h e t e r m h e m i c e l l u l o s e i s a c t u a l l y i n c o r r e c t when a p p l i e d to e n c r u s t i n g p o l y u r o n i d e s and for th is r e a s o n , i t s u s e s h o u l d be d i s c o u r a g e d ; that of c e l l u l o s a n i s e n t i r e l y m i s -l e a d i n g s ince i t i m p l i e s a l ong cha in with g lucose b a s e and intends to m e a n a s h o r t c h a i n with o t h e r - t h a n - g l u c o s e b a s e . U r o n i c a c i d s ( f r o m p o l y -u r o n i d e s ) i m p l y t e r m i n a l s i tuat ion or o c c u r r e n c e on a s i d e - c h a i n of known l inkage , w h e r e a s i n fact on ly the f o r m e r i s p r e s e n t . L a s t l y , this n o m e n -c l a t u r e takes no account of the x y l a n and m a n n a n ( f r o m c e l l u l o s a n s ) w h i c h 8 a r e often i n a s s o c i a t i o n with s e p a r a t e d o(, - c e l l u l o s e s . In an attempt to re f ine these s h o r t c o m i n g s , Stewart {117) extended N o r m a n ' s o r i g i n a l c l a s s i f i c a t i o n and n o m e n c l a t u r e of wood substance p o l y -s a c c h a r i d e s ( A p p e n d i x II). A n a l y t i c a l p r o c e d u r e s for d e t e r m i n i n g each const i tuent a r e known and, except for the f a i r s e p a r a t i o n of g l y c o s a n u r o n i d e s f r o m n o n - c e l l u l o s i c g l y c o s a n s , they give r e l a t i v e l y c l e a r - c u t s e p a r a t i o n s between a l l const i tuents , thus a l l owing a p p r o x i m a t i o n of the to ta l p o l y s a c c h a r i d e f r a c t i o n of wood subs tance . T h e t e r m i n o l o g y u s e d i s to be p r e f e r r e d to the o l d e r n o m e n c l a t u r e (94), as i t i s b a s e d on s y s t e m a t i c r a t h e r than t r i v i a l n o m e n c l a t u r e . W h i l e use of "osan" is g e n e r a l l y a p p l i e d to m a c r o m o l e c u l a r substances w h i c h h y d r o l y z e to give s u g a r s , S tewart has extended this def in i t ion to i n c l u d e o l i g o s a c c h a r i d e s as w e l l . S tewart ' s c l a s s i f i c a t i o n i s m u c h e a s i e r to u n d e r s t a n d and apply . C e r t a i n l y it abo l i shes m u c h confus ion attendant between u n d e r s t a n d i n g ac tua l v a r i a t i o n s i n wood c h e m i c a l const i tuents and methods u s e d for t h e i r m e a s u r e m e n t . M u c h of this h d s t o r i c a l and n o m e n c l a t u r e r e v i e w i s a lso a v a i l a b l e i n a p a p e r b y W i s e (152). II. V a r i a t i o n s i n C h e m i c a l O r g a n i z a t i o n i n W o o d W o o d i s of p lant o r i g i n and const i tutes the s e c o n d a r y x y l a r y p o r t i o n of c e r t a i n f i b r o v a s c u l a r t i s s u e s . T h e fo l lowing c r i t e r i a s e r v e to d i s t i n -gu i sh woody f r o m n o n - w o o d y plants (19, 96): woody plants have s p e c i a l i z e d conduct ing ( v a s c u l a r ) t i s s u e s that p r o d u c e x y l e m (wood) and p h l o e m ( inner b a r k ) ; these plants p r o v i d e a s t e m that p e r s i s t s and l i v e s for a n u m b e r of y e a r s , i n fact, s o m e woody p lants ( trees) a r e the o ldes t l i v i n g th ings; and, b e s i d e s exh ib i t ing the p r i m a r y growth w h i c h o c c u r s at a p i c a l g r o w i n g points 9 and causes e longat ion of t r e e s t e m s , woody plants exhibi t s e c o n d a r y th i cken ing , a m e a n s of s t e m t h i c k e n i n g a c h i e v e d t h r o u g h the a c t i v i t y of a growing l a y e r c a l l e d the c a m b i u m . T h e t e r m "wood" r e f e r s to p a r t of this c o l l e c t e d p r o d u c t of the c a m b i u m w h i c h , b e c a u s e of its o r i g i n , i s a l so r e f e r r e d to as s e c o n d a r y x y l e m . O r i g i n a t i n g f r o m a p i c a l growing po ints , p r i m a r y x y l e m i s f o r m e d on ly d u r i n g the f i r s t y e a r of growth i n such p lant s , hence , i s r e s t r i c t e d to i n i t i a l p o s i t i o n about the s t e m p i t h . A . T a x o n o m i c L e v e l T a x o n o m i c a l l y , t h e r e a r e t h r e e types of woody p lants : l i a n a s , s h r u b s , and t r e e s ; of these , the la t t er a r e the on ly ones of d i r e c t i n t e r e s t to W o o d S c i e n c e and, though s o m e t i m e s di f f icul t to s eparate f r o m the o t h e r s , they a r e u s u a l l y ident i f i ed f r o m t h e i r c h a r a c t e r i s t i c habi t of at ta ining a height of at l ea s t 20 feet at m a t u r i t y and h a v i n g a s e l f - s u p p o r t i n g s t e m . W i t h i n the plant k i n g d o m , t r e e s o c c u r on ly i n the P h y l u m S p e r m a t o p h y t a w h i c h , i n t u r n , i s s u b d i v i d e d into G y m n o s p e r m a e and A n g i o s p e r m a e . M u c h w o r k has b e e n done on the c o m p o s i t i o n and c h e m i c a l s t r u c t u r e of g r o s s wood f r o m these two d i v i s i o n s . - Such r e s u l t s a r e of i n t e r e s t b e c a u s e they i n d i c a t e changes i n the c e l l w a l l c h e m i c a l s t r u c t u r e w h i c h m a y have e v o l v e d d u r i n g the deve lopment of t e r r e s t r i a l p lant s . B o t h have i n c o m m o n the qual i ta t ive s i m i l a r i t y of conta in ing the four b a s i c wood component s . M a j o r quanti tat ive d i f f erences between these components , h o w e v e r , s e r v e to separate the two wood types . Recent ly , T i m e l l (131, 132, 1 3 3 ) h a s s u m m a r -i z e d the m o r e i m p o r t a n t d i f f erences i n c a r b o h y d r a t e c o m p o s i t i o n between A n g i o s p e r m a e and G y m n o s p e r m a e and showed t h e i r e v o l u t i o n a r y deve lopment 10 to be a s s o c i a t e d with d e c r e a s i n g contents of ga lactose , m a n n o s e , and a r a -b inose un i t s , and i n c r e a s i n g amounts of g lucose and x y l o s e un i t s . Stewart (118) notes that s u c h t r e n d s s e e m to be r e l a t e d to i n c r e a s e s i n the extent of s e c o n d a r y growth, as w e l l as to i n c r e a s e s i n the p r o p o r t i o n of s e c o n d a r y to p r i m a r y w a l l component s . T h e to ta l c e l l - w a l l p o l y s a c c h a r i d e s a r e u s u a l l y obta ined f r o m wood substance i n the f o r m of h o l o c e l l u l o s e , of w h i c h A n g i o s p e r m a e conta in f r o m 70 to 80%, and G y m n o s p e r m a e 60 to 75%, b a s e d on e x t r a c t i v e - f r e e wood. G l u c a n , as a p p r o x i m a t e d b y oc* - c e l l u l o s e , const i tutes 45 to 50% of the f o r m e r and 40 to 45% of the l a t t er (117); this i s c u s t o m a r i l y r e g a r d e d as the t r u e c e l l u l o s i c f r a c t i o n of wood c a r b o h y d r a t e s . A l p h a c e l l u l o s e i s the p r o p o r t i o n of h o l o c e l l u l o s e or pulp i n s o l u b l e i n a so lut ion of 17. 5% s o d i u m h y d r o x i d e at 2 0 ° C . (124). T h e t e r m , h o w e v e r , i s s t r i c t l y a r b i t r a r y , and does not i m p l y e x c l u s i v e l y a homogeneous g l u c o s a n for , i n v a r i a b l y , it contains s m a l l amounts of c a r b o n d i o x i d e - a n d f u r f u r a l - y i e l d i n g m a t e r i a l s , as w e l l as s ign i f i cant amounts of mannans f r o m softwoods (153). F r o m the l i t e r a t u r e r e l a t i n g to the n o n - c e l l u l o s i c wood p o l y s a c c h a r i d e s , H a m i l t o n and T h o m p s o n (54) r e a c h e d these c o n c l u s i o n s : to ta l n o n - c e l l u l o s i c p o l y s a c c h a r i d e s ( N o r m a n ' s h e m i c e l l u l o s e s ) r e p r e s e n t about 25% of a n g i o -s p e r m o u s wood, and 20% of g y m n o s p e r m o u s wood. E a c h conta in the fo l lowing enti t ies i n c o m m o n to both: g a l a c t o g l u c o m a n n a n , a r a b i n o g a l a c t a n and other g a l a c t o s e - c o n t a i n i n g p o l y m e r s , p e c t i n s , and s t a r c h . In contras t , v e r y m u c h l a r g e r amounts of 4 - 0 - m e t h y l g l u c u r o n o x y l a n (80 to 90% of total) a r e found i n A n g i o s p e r m a e , w h e r e a s m e d i u m to l a r g e amounts of a r a b i n o -11 4 - 0 - m e t h y l g l u c u r o n o x y l a n (15 to 30% of total) and g l u c o m a n n a n (60 to 70% of total) , r e s p e c t i v e l y , o c c u r i n G y m n o s p e r m a e . In addi t ion , m a n y p h y s i c a l m e a s u r e m e n t s have been p e r f o r m e d on s e p a r a t e d wood p o l y s a c c h a r i d e s (118, 129). F u r t h e r c h e m i c a l i n v e s t i g a t i o n has r e v e a l e d other d i f f erences between p o l y s a c c h a r i d e s of the two m a j o r g r o u p s . A c e t y l content of A n g i o s p e r m a e wood is about twice that of G y m n o s p e r m a e wood, b e i n g i n the o r d e r of 3 to 4%; m o s t of these a r e known to o c c u r as O - a c e t y l groups (22, 118). O n the other hand, G y m n o s p e r m a e conta in a p p r o x i m a t e l y 2 5% l i g n i n as c o m p a r e d to about 20% for A n g i o s p e r m a e and, of th is p e r c e n t a g e , m e t h o x y l content of the f o r m e r is about 15%, whi le that of the l a t t er i s c l o s e r to 20%. E x t r a c t i v e s , although quite v a r i a b l e i n c o m p o s i t i o n , const i tute an average of 3 to 5% for wood of e i ther g r o u p . W i t h i n the G y m n o s p e r m a e four l i v i n g o r d e r s a r e r e c o g n i z e d b y p r o b a b l e o r d e r of i n c r e a s i n g e v o l u t i o n a r y deve lopment , these a r e C y c a d a l e s , Ginkgo a les , C o n i f e r a les and G n e t a l e s . O n l y the t h i r d o r d e r , C o n i f e r a l e s , i s of c o m m e r c i a l i m p o r t a n c e , m a i n l y b e c a u s e of the g r e g a r i o u s na ture of i ts s p e c i e s ( tending to beget t r e e e x t r a c t i o n on an e c o n o m i c l eve l ) , t h e i r e x c u r r e n t m o d e of growth, and the d i v e r s i t y of t h e i r wood u s e s . A m o n g the C o n i f e r s , c h e m i c a l s tudies of v a r i a t i o n s i n p o l y s a c c h a r i d e s a r e m o r e l i m i t e d and m u c h m o r e data i s needed b e f o r e g e n e r a l i z a t i o n s can be m a d e r e g a r d i n g d i f f erences between f a m i l i e s or l e s s e r t a x o n o m i c s u b -d i v i s i o n s . W h i l e - c e l l u l o s e i s c o n s i d e r e d the s a m e c h e m i c a l l y , i n t e r -g e n e r a v a r i a t i o n s i n h e t e r o g l y c a n s have b e e n noted. S c h w a r t z and T i m e l l (109) e x t r a c t e d g a l a c t o g l u c o m a n n a n f r o m P a c i f i c s i l v e r f i r ( A b i e s a m a b i l i s 12 ( D o u g l . ) F o r b . ) and found two types h a v i n g d i f f erence m o n o s a c c h a r i d e r a t i o s and degree of p o l y m e r i z a t i o n ( D P ) ; T i m e l l (132) e a r l i e r s tud ied h e t e r o -g lycans of v a r i o u s spec i e s of the g e n e r a P i n u s , P i c e a, Tsuga , A b i e s and T h u j a . H e showed that, whi le ga lac tog lucomannans w e r e s i m i l a r for a l l genera , e a c h exh ib i ted c h a r a c t e r i s t i c m o n o s a c c h a r i d e r a t i o s . F u r t h e r m o r e , he c o n c l u d e d that with a few except ions , a l l con i f erous g lucomannans conta in 2 to 4% ga lac tose , and that con i f erous wood m a y conta in 10 to 20% of a c l o s e l y r e l a t e d s e r i e s of ga lac tog lucomannans d i f f e r i n g m a i n l y i n t h e i r r e l a t i v e ga lac tose content and p e r h a p s a lso i n t h e i r a v e r a g e D P (or m o l e c u l a r weight) and c h a i n b r a n c h i n g . S c h u e r c h (108) r e p o r t e d that the la t ter c h a r a c t e r i s t i c s e l d o m exceeds 3 b r a n c h e s p e r 100 uni t s , and that i n c e r t a i n c o n i f e r s , the po int of O - a c e t y l group at tachment v a r i e s . In s o m e spec ie s of L a r i x , e s p e c i a l l y l a r g e amounts of a h i g h l y b r a n c h e d a r a b i n o g a l a c t a n have b e e n found (132). A n o t h e r w i s e i m p o r t a n t point about a r a b i n o g a l a c t a n i s that it i s found o n l y i n P i n a c e a e . S c h u e r c h (108) has l i s t e d a b i b l i o -g r a p h y r e l a t i n g to i n t e r - g e n e r a v a r i a t i o n s i n s o m e h e m i c e l l u l o s e s . E r d t m a n (39) has a p p l i e d d i f f erences i n e x t r a c t i v e c h e m i s t r y to d i s t i n g u i s h wi th in and between the F a m i l i e s P i n a c e a e , P o d o c a r p a c e a e , A r a u c a r i a c e a e , T a x o d i a c e a e , and C u p r e s s a c e a e . I n t e r - s p e c i e s v a r i a t i o n i n a l l c h e m i c a l components i s conven ient ly l i s t e d b y B r o w n i n g (22) and T i m e l l (135); these c o v e r the m o r e i m p o r t a n t c o m m e r c i a l N o r t h A m e r i c a n woods . B r o w n i n g (22) a l so has shown e l e m e n t a l a n a l y s i s of s o m e of these s p e c i e s . G e n e r a l l y , c h e m i c a l v a r i a t i o n between spec ie s is l e s s than that between genera; h o w e v e r , m a n y except ions have been r e p o r t e d . W i t h i n a s p e c i e s , c h e m i c a l c o m p o s i t i o n v a r i e s u n p r e d i c t a b l y , due to the m u l t i p l e effects of growth condi t ions ava i lab le wi th in and between fores t s and, as r e s u l t of the la t t er , t h e r e s e e m s to have b e e n deve lopment of s o - c a l l e d r a c e s wi th in spec ies (96). Some s t r u c t u r a l features and p h y s i c a l c h a r a c t e r i s t i c s (hence, a l so c h e m i c a l c h a r a c t e r i s t i c s ) a r e i n h e r i t e d (96) and, b e c a u s e of th i s , t r e e -b r e e d i n g p r o g r a m s a r e now o p e r a t e d i n a n u m b e r of c o u n t r i e s , with s p e c i a l attention b e i n g p a i d to these a s p e c t s . B . W o o d Zone L e v e l W i t h i n a s ing le c o n i f e r o u s s t e m , the r a d i a l p a t t e r n of C r o s s and B e v a n c e l l u l o s e d i s t r i b u t i o n for Douglas f i r ( P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o ) and M o n t e r e y p ine ( P i n u s r a d i a t a D . D o n . ) has b e e n shown to r a p i d l y i n c r e a s e i n the f i r s t 10 to 15 y e a r s , f r o m the p i t h outward , and therea f t er l e v e l o f f (141, 160). Z o b e l and M c E l w e e (160) ; c o n f i r m e d these r e s u l t s for l o b l o l l y p ine ( P i n u s taeda L . ) a l s o where - c e l l u l o s e content of sapwood was h i g h e r b y 7% than that n e a r the p i th . L a r s o n (76) r e c e n t l y d e t e r m i n e d the f ive p r i n c i p a l wood sugars and l i g n i n a c r o s s r a d i i of t h r e e m a t u r e r e d p ine ( P i n u s r e s i n o s a L . ) s t e m s and showed that g lucose and m a n n o s e y i e l d s i n c r e a s e d r a p i d l y with age, w h e r e a s y i e lds of x y l o s e , ga lac tose , a r a b i n o s e , and l i g n i n d e c r e a s e d (the la t t er d e c l i n e d v e r y g r a d u a l l y ) . H e fur ther showed that l i g n i n i n c r e a s e d b y 2% f r o m 6 ft to 18 ft i n height . K l e m (70) and H a t a (55)>reported s i m i l a r r e s u l t s for N o r w a y s p r u c e ( P i c e a abies L . ( K a r s t . ) and J a p a n e s e r e d pine ( P i n u s d e n s i f l o r a L . ), r e s p e c t i v e l y . Well-wood et a l . (147) showed that, a c r o s s a s t e m r a d i u s of w e s t e r n h e m l o c k ( T s u g a h e t e r o p h y l l a Raf . S a r g . )* s p e c i f i c g r a v i t y fol lows the s a m e g e n e r a l t r e n d as that for c e l l u l o s e content. K e n n e d y and J a w o r s k y (68) showed these two p r o p e r t i e s to be c o r r e l a t e d i n Douglas f i r . T h e r e f o r e , c e l l u l o s e content m a y be expected to fo l low the s a m e p a t t e r n as that of s p e c i f i c g r a v i t y i n ob l ique and height s e r i e s of Douglas f i r and the p r e c e d i n g spec i e s c i t e d for c e l l u l o s e content, that i s , c e l l u l o s e y i e l d c o u l d be expected to d e c r e a s e f r o m the butt u p w a r d . E x t r a c t i v e pa t t erns have b e e n e s t a b l i s h e d a c r o s s r a d i i of r e d w o o d (Sequoia s e m p e r v i r e n s ( D . Don) E n d l . ) (110), w e s t e r n l a r c h ( L a r i x o c c i d e n t a l i s Nutt . ), Douglas f i r (13, 45), and w e s t e r n r e d c e d a r ( T h u j a p l i c a t a Donn.) (83). B o t h p o l y -pheno l and t h u j a p l i c i n contents i n c r e a s e d f r o m the p i t h to the h e a r t w o o d -sapwood p e r i p h e r y , after w h i c h the f o r m e r d e c r e a s e d r a p i d l y and the la t t er d i s a p p e a r e d . In contras t , r e s i n s f r o m a n u m b e r of p ines appear to be h ighes t i n the p i th r e g i o n and therea f t er d e c r e a s e g r a d u a l l y to the b a r k (5, 27, 78, 110). L u x f o r d (81) has s tud ied the effect of e x t r a c t i v e s o n s trength of whole wood . W o o d zone d i f f erences s i m i l a r l y r e f l e c t the above t r e n d s : juven i l e wood i s r e g a r d e d as the c e n t r a l p o r t i o n of the s t e m o c c u p y i n g the f i r s t 15 to 20 r i n g s and m a t u r e wood i s that f o r m e d subsequent ly . T h e l a t t er p o s s e s s e s c h a r a c t e r i s t i c s c o n s i d e r e d r e g u l a r for the s p e c i e s , whi l e juven i l e wood, on the other hand, has c h e m i c a l p r o p e r t i e s d i f ferent f r o m those of m a t u r e wood. T r e n d s r e l a t i n g c e l l u l o s e , l i g n i n , and e x t r a c t i v e contents between these zones have been d i s c u s s e d . In s u m m a r y , wi th in juven i l e wood, c e l l u l o s e content appears to r i s e abrupt ly , p o l y p h e n o l and t h u j a p l i c i n contents i n c r e a s e g r a d u a l l y , and l i g n i n and r e s i n contents d e c r e a s e s lowly; i n m a t u r e hear twood , these t rends continue, but at m o r e g r a d u a l r a t e s . C a m b i a l zones m a y conta in up to 20% i n o r g a n i c ash, 50% ethanol so lub les , 30% p r o t e i n , 35% n o n - c e l l u l o s i c p o l y s a c c h a r i d e s but l i t t l e (up to 25%) c e l l u l o s e o r l i g n i n (118). In g e n e r a l , r e g u l a r wood i s that f o r m e d b y n o r m a l p h y s i o l o g i c a l p r o c e s s e s r e s u l t i n g i n equa l c a m b i a l d i v i s i o n of c e l l s throughout the t r e e c i r c u m f e r e n c e . W h e n i n s p e c t e d f r o m p i th to b a r k along a r a d i u s , i ts m o s t c h a r a c t e r i s t i c q u a l i t y i s f requent ly , but not a lways , the p r e s e n c e of two d i s t i n c t l y c o l o r e d zones of growth: h e a r t w o o d (duramen) •. and sapwood ( a l b u r n u m ) . T h e la t ter o c c u p i e s the p e r i p h e r a l r e g i o n o f s e c o n d a r y x y l e m i n w h i c h a p o r t i o n of the t i s s u e (5 to 40%)is l i v i n g , hence , p h y s i o l o g i c a l l y a c t i v e . Its s u s p e c t e d funct ions a r e s t e m support , sap conduct ion up the t r e e , and r e s e r v e food s t o r a g e . W i t h t i m e and i n c r e a s i n g g i r t h , h o w e v e r , the p r o t o p l a s m of a l l l i v i n g x y l a r y c e l l s i s thought to die and s e c o n d a r y changes a c c r u i n g f r o m this r e s u l t i n f o r m a t i o n of h e a r t w o o d , the p h y s i o -l o g i c a l l y dead, c e n t r a l c o n i c a l c o r e of the s t e m x y l e m . S i m i l a r death changes p r o b a b l y o c c u r i n the p h l o e m . F o r m a n y s p e c i e s , the t r a n s i t i o n of sapwood into h e a r t w o o d i s c h a r a c t e r i z e d b y a change f r o m a c r e a m y - w h i t e c o l o r to an a p p r e c i a b l y d a r k e r c o l o r , the d e m a r c a t i o n zone b e i n g e i ther abrupt o r g r a d u a l . In 16 other g e n e r a s u c h as P i c e a , T s u g a , A b i e s , or P o p u l u s , th is c o l o r change m a y be i m p e r c e p t i b l e (96). D a r k h e a r t w o o d v i s u a l l y i l l u s t r a t e s that s o m e c h e m i c a l change has o c c u r r e d i n t r a n s i t i o n between the zones; v a r i o u s o r g a n i c substances s u c h as e x t r a c t i v e s , extraneous m a t e r i a l s , o r i n f i l -t ra t ions a r e thought to pass into the l u m e n s and c e l l w a l l s . T o be s u r e , this p h e n o m e n o n o c c u r s i n spec i e s of l i ght heartwood; however , t h e i r e x t r a c -t ives l a c k s u c h a h i g h degree of ox idat ion . T h e t o x i c i t y of s o m e e x t r a c t i v e substances is w e l l - k n o w n (67, 83, 84); th i s , with the i n h i b i t e d m o v e m e n t of m o i s t u r e and a i r ( c a u s e d p o s s i b l y b y the i n f i l t r a t i o n o r m o r p h o l o g i c a l changes , i . e. t y lo se s ) , i s thought to r e n d e r h e a r t w o o d m o r e r e s i s t a n t to p e n e t r a t i o n than sapwood. A s i n d i c a t e d p r e v i o u s l y , c o r e w o o d hear twood , b e c a u s e of i t s c e n t r a l p o s i t i o n wou ld be expected to conta in on the average , l e s s c e l l u l o s e and m o r e l i g n i n than m a t u r e h e a r t w o o d and sapwood, whi le a c e t y l content wou ld be c o n s i s t e n t l y h i g h e r i n sapwood (22). I r r e g u l a r h e a r t w o o d has b e e n noted i n Douglas f i r (69) and w e s t e r n r e d c e d a r (84) f r o m the i n t e r i o r of B r i t i s h C o l u m b i a . P a t t e r n s of d i -h y d r o q u e r c e t i n and t h u j a p l i c i n d i s t r i b u t i o n appear to fo l low a l ternate l i g h t -and d a r k - c o l o r e d c o n c e n t r i c bands of v a r i a b l e width wi th in the h e a r t w o o d ("target r ing") ; the l i g h t e r bands appear to be m o r e c l o s e l y r e l a t e d b y c h e m i c a l e x t r a c t i v e content to sapwood than to h e a r t w o o d . In c o n t r a s t to r e g u l a r wood, r e a c t i o n wood i s f r e q u e n t l y c o r r e l a t e d with a c h a r a c t e r i s t i c ana tomy and e c c e n t r i c r a d i a l growth; both r e s u l t f r o m d i f f e r e n t i a l (unequal) c a m b i a l d i v i s i o n of c e l l s on one s ide of a s t e m , s e e m i n g l y i n r e s p o n s e to g r a v i t y a n d / o r growth h o r m o n e s (142, 145). In c o n i f e r s , g r e a t e r c a m b i a l d i v i s i o n o c c u r s on the l o w e r s ide , g i v i n g r i s e to " c o m p r e s s i o n " wood; this m a y l e a d to an e c c e n t r i c p i th . C h e m i c a l ana lyse s of c o m p r e s s i o n wood have been s u m m a r i z e d (89, 96). T h e r e s e e m s to be a c e r t a i n b a l a n c e w h i c h n o r m a l l y ex is t s between the f o r m a t i o n of l i g n i n and c e l l u l o s e i n g r o s s wood. T h i s b a l a n c e , wi th in l i m i t s of n u m e r o u s s o u r c e s of v a r i a t i o n , m a y be shi f ted one way or the other b y a m e c h a n i s m adjust ing to the s t r e s s o r s t r a i n to w h i c h the d e v e l o p -ing wood t i s s u e is subjec ted . One e x p r e s s i o n of this shift o c c u r s v i v i d l y wi th r e a c t i o n wood f o r m a t i o n . In con i f erous t r e e s , a m a r k e d change f r o m that of r e g u l a r wood is shown at the l e v e l of c h e m i c a l c o m p o s i t i o n . In Scots p ine ( P i n u s s y l v e s t r i s L . ) , M e i e r (89) has shown that a long with h igher ga lac tan and pentosan content, the amount of l i g n i n i n c r e a s e s a p p r o x i m a t e l y 10%. T h i s i s a c c o m p a n i e d b y s m a l l e r amounts of g a l a c t o -g l u c o m a n n a n and a r e d u c t i o n i n c e l l u l o s e content o f a p p r o x i m a t e l y 10 to 15%. L a r s o n (76) obta ined s i m i l a r r e s u l t s f r o m r e d pine and, a c c o r d i n g to S tewart (118), S c h w e r i n found l i k e w i s e for M o n t e r e y p i n e . B y r d et a l . (26) s tud ied t h r e e r a d i a l pos i t i ons and heights w i th in each o f four 3 7 - y e a r -o l d l o b l o l l y p ine s t e m s . R e g r e s s i o n ana lys i s showed c h l o r i t e a l p h a - c e l l u -l o s e and l i g n i n to be n e g a t i v e l y and s i g n i f i c a n t l y c o r r e l a t e d (r = - 0 . 764). 18 C . G r o w t h Zone and T i s s u e L e v e l A c r o s s con i f erous growth zones , c h e m i c a l v a r i a t i o n s o c c u r between l o n g i t u d i n a l and t r a n s v e r s e t i s s u e s . A c c o r d i n g to T i m e l l (135); P e i r i l a and c o - w o r k e r s s tud ied c a r b o h y d r a t e c o m p o s i t i o n of p a r e n c h y m a ( r a y and longi tudinal ) and t r a c h e i d c e l l s i n Scots p ine and N o r w a y s p r u c e . In the f o r m e r , h e m i c e l l u l o s e content of p a r e n c h y m a and t r a c h e i d s was 20 and 21%, r e s p e c t i v e l y , whi le i n the la t t er , the va lues w e r e 30 and 18%, r e s p e c t i v e l y . In both s p e c i e s , p a r e n c h y m a c e l l s conta ined m o r e x y l o s e than m a n n o s e r e s i d u e s , whi l e i n t r a c h e i d s m a n n o s e p r e d o m i n a t e d . T h o m p s o n et a l . (125). showed that p o l y s a c c h a r i d e s r i c h i n ga lac tose , a r a b i n o s e , and u r o n i c ac ids p r e d o m i n a t e i n e p i t h e l i a l c e l l s , and that these c e l l s a r e l o w e r i n g lucose b y a p p r o x i m a t e l y 10%. F r o m this ev idence , i t appears p o s s i b l e that each c e l l type has a c h a r a c t e r i s t i c c a r b o h y d r a t e c o m p o s i t i o n . M e i e r (89) and H a a s and K r e m e r s (51) have c o m p a r e d d i f ferences i n p o l y s a c c h a r i d e content for m a t u r e and i m m a t u r e p ine t r a c h e i d s . V a r i a t i o n s ex i s t ing between and a m o n g e a r l y - and la tewood t i s s u e s c o n t r o l the m o s t p r o n o u n c e d d i f f erences found i n wood qual i ty , hence , the inf luence of s u c h v a r i a t i o n s on the c h e m i c a l deve lopment a c r o s s a growth zone w i l l have a m o s t i m p o r t a n t b e a r i n g on a wood's u l t i m a t e u t i l i z a t i o n . M o r p h o l o g i c a l v a r i a t i o n s wi th in a t r e e r e f l e c t the inf luence of t e r m i n a l m e r i s t e m s (74);and m o i s t u r e a v a i l a b i l i t y (158); fo l lowing d o r m a n c y , r e s u m p t i o n of c a m b i a l a c t i v i t y i s a c c o m p l i s h e d through v e r t i c a l aux in t r a n s l o c a t i o n f r o m the c r o w n , c a u s i n g r a d i a l e n l a r g e m e n t o f i m m a t u r e t r a c h e i d s to f o r m e a r l y w o o d . N a t u r a l l y , as the auxin r e a c h i n g the c a m b i u m d e c r e a s e s with d i s tance f r o m the c r o w n , the magni tude and d u r a t i o n of e a r l y w o o d f o r m a t i o n i s l e a s t at the t ree b a s e . T h i s condi t ion r e m a i n s as long as m o i s t u r e is h i g h l y a v a i l a b l e , but wi th d e c r e a s i n g m o i s t u r e (as i n s u m m e r months) , r a d i a l c e l l e n l a r g e m e n t d e c r e a s e s and d i f f erent ia ted ce l l s r e m a i n a l ive l o n g e r , hence , w a l l s b e c o m e t h i c k e r , and la tewood f o r m s (36). T h e m e c h a n i s m b y w h i c h t r a n s i t i o n o c c u r s i s s t i l l i n doubt. Z a h n e r (159) c l a i m s it beg ins after the f i r s t s e v e r e water def ic i t , but L a r s o n (75) b e l i e v e s a d e c r e a s i n g aux in supply to be the cause . F o l l o w i n g t r a n s i t i o n , however , a m i l d m o i s t u r e def ic i t f a v o r s la tewood fo r m a t i o n (159). R e c e n t c h e m i c a l ev idence b y W u and W i l s o n (157) suggests the o c c u r r e n c e of two e a r l y w o o d types wi th in an i n c r e m e n t ( E ^ and E ^ ) , ^ e f i r s t c o r r e s p o n d i n g to wood a r i s i n g f r o m " o v e r - w i n t e r e d " x y l a r y m o t h e r c e l l s , the s e c o n d r e l a t i n g to that f o r m e d b y new c a m b i a l d i v i s i o n s wi th in a g r o w i n g s eason . It i s p r o p o s e d , t h e r e f o r e , that E ^ m i g h t "retain some s i m i l a r i t y at the c h e m i c a l l e v e l of o r g a n i z a t i o n to l a s t - f o r m e d t i s sues of the p r e c e d i n g season" (157). T h e o r i g i n of these t i s s u e s has been d e m o n s t r a t e d b y B a n n a n (10) who has r e m o v e d and s tudied deve lop ing wood throughout s ing le g r o w i n g seasons . F r o m n o r t h e r n white c e d a r ( T h u j a o c c i d e n t a l i s L . ) g r o w n i n the T o r o n t o , O n t a r i o a r e a , B a n n a n (10) found that, on r e s u m p t i o n of c a m b i a l ac t iv i ty , the f i r s t s i te of c e l l d i v i s i o n is i n the o ldes t x y l a r y m o t h e r ce l l s contiguous to the a l r e a d y d i f f erent ia ted x y l e m ; f u r t h e r m o r e , the great m a j o r i t y of these c e l l s , and not the s p e c i f i c l a y e r ( s ) o f c a m b i a l i n i t i a l s , a r e m o s t act ive d u r i n g the f i r s t month(s) of r a d i a l growth . T h e r e f o r e , Barman (12) o b s e r v e s , a c o n s i d e r a b l e p o r t i o n of e a r l y w o o d m a y be f o r m e d b y r e d i v i s i o n of ( o v e r -wintered) x y l e m m o t h e r c e l l s ; this p o r t i o n m a y i n c l u d e anywhere between 2 to 24 (average of 8),such c e l l s (11). Some c h e m i c a l b a c k g r o u n d ex is t s as to c h e m i c a l d i f f erences a c r o s s a growth zone. E a r l y - and la tewood c a r b o h y d r a t e d i f f erences w e r e f i r s t noted b y R i t t e r and F l e c k (102) who r e p o r t e d c e l l u l o s e content of w e s t e r n white p ine ( P i n u s m o n t i c o l a D o u g l . ) , Douglas f i r , and l o b l o l l y p ine to be s i g n i f i c a n t l y h i g h e r (2 to 5%) i n latewood; this s a m e r e l a t i o n s h i p has been i n d i c a t e d for h o l o c e l l u l o s e components of Douglas f i r (9, 53), r e d p ine (53), l o b l o l l y p ine (160); J a p a n e s e r e d p ine (55); and Scots p ine (89). H y d r o l y -zates f r o m growth zones have b e e n s tud ied a l s o : M e i e r (89) and M e i e r and W i l k i e (90) showed that i n Scots p ine , g lucose (ce l lu lose ) content was a constant 56% a c r o s s the r i n g , whi l e g l u c o m a n n a n content i n c r e a s e d b y 4% and that for a r a b i n o g l u c u r o n o x y l a n d e c r e a s e d b y 4%. L a r s o n (76) showed a l m o s t i d e n t i c a l pa t terns i n r e d p ine; at constant age, g lucose r e c o v e r y f r o m la tewood c o n s i s t e n t l y exceeded that of e a r l y w o o d b y 1 to 2%, and that for m a n n a n i n la tewood was a l so 3 to 4% h i g h e r . A r a b i n a n and x y l a n y i e l d s w e r e h i g h e r b y 1 to 2% i n e a r l y w o o d . L a r s o n (76) ,expla ined that, whi le the i n c r e a s i n g g lucose and m a n n o s e va lues ( throughout a r a d i u s ) a r e age-dependent , they m a y be m o d i f i e d b y the a g e - r e l a t e d i n c r e a s e i n w a l l t h i c k n e s s . A s u m m a r y of such data a v a i l a b l e f r o m the l i t e r a t u r e i s p r e s e n t e d i n T a b l e 1. It i s i m p o r t a n t to note that a l l these o b s e r v a t i o n s a r e b a s e d on s a m p l i n g on ly two points wi th in a growth i n c r e m e n t , f r e q u e n t l y with u n u s u a l l y w i d e - r i n g e d m a t e r i a l s . O n l y two p r e v i o u s studies have i n c l u d e d s a m p l i n g m o r e than two points w i th in an i n c r e m e n t . C a r b o h y d r a t e d i s t r i b u t i o n was s tud ied for s ix points wi th in e a c h of t h r e e Douglas f i r i n c r e m e n t s . U s i n g a p r o c e d u r e i n v o l v i n g 0. 5 g wood m e a l and known to have s e r i o u s l i m i t a t i o n s i n s t a t i s t i c a l r e l i a b i l i t y , Ifju (61); showed that for each r i n g , peak c h l o r i t e h o l o c e l l u l o s e as d e t e r m i n e d b y the Z o b e l and M c E l w e e (160) m e t h o d (77 to 78%) o c c u r r e d at the e a r l y w o o d - l a t e w o o d t r a n s i t i o n , whi le f i r s t and l a s t - f o r m e d pos i t i ons i n the i n c r e m e n t gave l o w e r va lues (72 to 73%). In a l a t e r study, these " m i c r o " - h o l o c e l l u l o s e s w e r e c o r r e c t e d for a r e s i d u a l l i g n i n d e t e r m i n a t i o n a p p l i e d for the f i r s t t i m e (151). T h i s m i c r o - K a p p a m e t h o d (149) has been e x a m i n e d and r e c o n f i r m e d . H y d r o l y z a t e s of g lucan p lus m a n n a n (88 to 94% of the h o l o c e l l u l o s e ) fo l lowed the h o l o c e l l u l o s e p a t t e r n , whi le ga lac tan i n c r e a s e d a c r o s s each i n c r e m e n t (2. 5 to 6%), and pentosans d e c r e a s e d (xylan, 8 to 4. 5%; a r a b i n a n , 0. 6 to 0.2%). Ifju a l so d e t e r m i n e d m e a n c e l l u l o s e cha in lengths for e a r l y - and la tewood c e l l u l o s e n i t ra te s d i s s o l v e d i n acetone. M e a n i n t r i n s i c v i s c o s i t y for each of t h r e e i n c r e m e n t s was 34 d l / g i n e a r l y w o o d and 36 d l / g i n la tewood . M a r k (88); s tudied r e s i s t a n t c a r b o h y d r a t e b y C r o s s and B e v a n a n a l y s i s i n e a r l y - and l a t e - e a r l y w o o d and la t ewood of e a s t e r n r e d cedar ( J u n i p e r u s  Virginian a L . ). In o r d e r , each conta ined 45. 0%, 49. 3%, and 57. 7% r e s i s t a n t c a r b o h y d r a t e . B e s i d e s not ing e a r l y w o o d - l a t e w o o d d i f f erences in c a r b o h y d r a t e y i e l d , m a n y of the p r e c e d i n g authors a lso r e p o r t e d s i m i l a r quanti tat ive d i f f erences i n l i g n i n contents , but with the h i g h e r va lues i n each case b e i n g d e r i v e d f r o m e a r l y w o o d . W u and W i l s o n (157) have tabulated s u c h e a r l y w o o d - l a t e w o o d va lues for l i g n i n c o m p a r i s o n s i n con i f erous woods a v a i l a b l e i n the l i t e r a t u r e . U s i n g e x t r a c t e d wood m e a l f r o m t h r e e adjacent i n c r e m e n t s of m a t u r e wood, i n t r a - i n c r e m e n t l i g n i n contents of f ive w e s t e r n con i f erous woods w e r e i n v e s t i g a t e d b y W u (156). In the great m a j o r i t y of i n c r e m e n t s s tudied , e a r l y w o o d was h i g h e r i n l i g n i n p e r c e n t a g e than la tewood, the a v e r a g e d i f f erence between these b e i n g , for i n d i v i d u a l s p e c i e s : Douglas f i r , 2.27%; P a c i f i c s i l v e r f i r , 2.06%; w e s t e r n r e d c e d a r , 1.28%; S i t k a s p r u c e , ( P i c e a s i t chens i s ( B o n g . ) * C a r r . ) 1. 08%; and w e s t e r n h e m l o c k , 0.46%. T h r e e d i f ferent d i s t r i b u t i o n pat terns w e r e evident: 1) l i g n i n i n c r e a s e d f r o m P o s i t i o n 1 to 2 i n e a r l y w o o d and d e c r e a s e d therea f t er to P o s i t i o n 6 i n latewood; 2 ) , l i gn in d e c r e a s e d p r o g r e s s i v e l y f r o m P o s i t i o n 1 to 6; and 3 ) . l ign in i n c r e a s e d f r o m P o s i t i o n 1 to 2 and r e m a i n e d constant therea f t er f r o m P o s i t i o n s 3 t h r o u g h 6. W u found a h i g h l y s ign i f i cant c o r r e l a t i o n for l i g n i n p e r c e n t a g e s between pos i t i ons wi th in growth i n c r e -ments for r e p r e s e n t a t i v e s of the f i r s t p a t t e r n ( P a c i f i c s i l v e r f i r , Douglas f i r , and w e s t e r n r e d cedar) and the r e p r e s e n t a t i v e of the s e c o n d pa t t ern , S i tka s p r u c e . B e t w e e n growth i n c r e m e n t s , Douglas f i r and w e s t e r n r e d c e d a r showed h i g h l y s igni f icant c o r r e l a t i o n s . In. o r d e r to obta in s t a n d a r d c a l i b r a t i o n , K l a s o n l i g n i n was p r e p a r e d . S ince a p o r t i o n of this i s a c i d -so luble , W u ' s va lues m a y be s l i ght ly low. W u (155) showed that m e t h o x y l contents of these spec i e s fo l lowed s i m i l a r pat terns wi th in i n c r e m e n t s . T h e f i r s t p a t t e r n of Wu's l i g n i n d i s t r i b u t i o n has a l so b e e n shown to ex i s t for Douglas f i r p o l y p h e n o l s , as s a m p l e d at eight p o s i t i o n s a c r o s s a s ing le i n c r e m e n t (113, 114); m a x i m u m va lues for q u e r c e t i n , d i h y d r o q u e r -cet in , d i h y d r o k a e m p f e r o l , and p i n o b a n k s i n a l l o c c u r e d within , but not at the i n i t i a t i o n of, e a r l y w o o d . T h e s e m a x i m a o c c u r r e d at a r e l a t i v e p o s i t i o n of about 20% and t herea f t er f e l l off m a r k e d l y to t r a n s i t i o n wood and l e v e l l e d off t h r o u g h the la tewood r e g i o n . T h i s p o s i t i o n is analogous to P o s i t i o n 2 i n W u ' s l i g n i n p a t t e r n . T h e r e i s l i t t l e chance these two pat terns a r e c o i n c i d e n t a l ; the i n f e r e n c e is that a f l a r o n o i d - o r i e n t e d d i s t r i b u t i o n p a t t e r n exis ts at l e a s t wi th in Douglas f i r growth zones and p o s s i b l y i n other con i f erous woods h a v i n g s i m i l a r f l a v o n o i d e x t r a c t i v e s . T h i s a f f i r m s the dual e a r l y w o o d hypothes i s of W u and W i l s o n (157). It has b e e n suggested that both l i g n i n and fLavonoids o r i g i n a t e f r o m a c o m m o n c i n n a m i c a c i d p r e c u r s o r (14). T h i s i s e n t i r e l y p l a u s i b l e . In buckwheat , for e x a m p l e , p - c o u m a r i c a c i d is the l a s t p r e c u r s o r c o m m o n to synthes i s of both l i g n i n and q u e r c e t i n . Some ev idence exis ts as to p h y s i c a l d i f f erences a c r o s s a con i ferous growth zone. I n t r a - i n c r e m e n t t e n s i l e and r a d i a l c o m p r e s s i v e s trengths of s i x con i f erous woods have been s tudied b y H o m o k y (59); r e g r e s s i o n s of both s trength p r o p e r t i e s and s p e c i f i c g r a v i t y showed h i g h l y s igni f icant r e l a t i o n s h i p s . C o m p a r e d wi th g r o s s wood, i t was found that, i n both p r o p e r t i e s , s p e c i f i c g r a v i t y was r e s p o n s i b l e for g r e a t e r s t r e s s i n c r e a s e of g r o s s wood than of t i s s u e . In woods h a v i n g a g r a d u a l t r a n s i t i o n , d i s t r i b u t i o n of s p e c i f i c g r a v i t y , m a x i m u m tens i l e s t r e s s , and m a x i m u m c o m p r e s s i o n s t r e s s r i s e s g r a d u a l l y f r o m e a r l y w o o d , then c u r v e s u p w a r d at the l a s t - f o r m e d la tewood. In those woods h a v i n g abrupt t r a n s i t i o n , the d i s t r i b u t i o n of these p r o p e r t i e s fo l lows a s i g m o i d c u r v e . T h e exp lanat ion of these pat terns i s g iven i n t e r m s of p e r i o d i c i t y of, and v a r i -ations i n , c e l l w a l l t h i c k n e s s . Ifju et a l . (62) found the s a m e s i g m o i d d i s t r i b u t i o n of s p e c i f i c g r a v i t y i n Douglas f i r w h i c h , . when c o r r e l a t e d with t ens ion p a r a l l e l to g r a i n e l a s t i c i t y , and u l t i m a t e t e n s i l e s trength , gave h i g h l y s ign i f i cant r e s u l t s . Ifju (61) p r e v i o u s l y showed t ens ion p a r a l l e l to be a funct ion of c e l l u l o s e p r o p e r t i e s . Ifju et a l . (62) and H o m o k y (59) deve loped s p e c i f i c g r a v i t y p r o f i l e s for f ive w e s t e r n c o n i f e r s and found that a b r o a d e r r a n g e a c c o m p a n i e d woods wi th abrupt e a r l y w o o d - l a t e w o o d t r a n s i t i o n (e. g. 0. 2 - 0 . 7) W o r r a l l (154) showed s ign i f i cant c o r r e l a t i o n between s p e c i f i c g r a v i t y and c e l l w a l l a r e a and found c e l l w a l l dens i ty to v a r y d i r e c t l y with that of wood dens i ty . T h e effect of f e r t i l i z e r t r e a t m e n t on i n t r a - i n c r e m e n t s trength of w e s t e r n r e d c e d a r has b e e n e x a m i n e d (147). F o l l o w i n g a p p l i c a t i o n of h igh n i t r o g e n content f e r t i l i z e r , growth ra te i n c r e a s e d , a c c o m p a n i e d b y a d e c r e a s e d s p e c i f i c g r a v i t y , t e n s i l e s trength, s t i f fness and a v e r a g e t r a c h e i d l ength . 25 M o r p h o l o g i c a l v a r i a t i o n s have b e e n s tudied a c r o s s con i f erous growth i n c r e m e n t s . W i t h i n any one growth zone, the a v e r a g e length of la tewood ce l l s was g r e a t e r than that of e a r l y w o o d (99); a l so , t h e r e s e e m s to be a definite p a t t e r n throughout the increment ; . T h i s p h e n o m e n o n i s a lso found i n A n g i o s p e r m a e (57). B i s s e t e t a l . (17) and B i s s e t and D a d s w e l l (16) have shown that, f o l l owing i n c e p t i o n of growth i n Douglas f i r , c e l l l ength d e c r e a s e s to a m i n i m u m i n the f i r s t p o r t i o n of e a r l y w o o d and thereaf ter i n c r e a s e s to a m a x i m u m i n the latewood, e i ther r a p i d l y or s lowly , depending on the na ture of the e a r l y w o o d - l a t e w o o d t r a n s i t i o n . Studies on v a r i a b i l i t y of this and other c e l l d i m e n s i o n s have been s u m m a r i z e d (36)j as w e l l as the effect of e x t e r n a l e n v i r o n m e n t upon such v a r i a b i l i t y (99). D. C e l l W a l l O r g a n i z a t i o n A t the c e l l u l a r l e v e l , the r e l a t i v e p e r c e n t a g e s of p o l y s a c c h a r i d e s i n the d i f ferent c e l l w a l l l a y e r s has b e e n e s t i m a t e d b y M e i e r (89) b y d i f f e r e n t i a t -i n g t i s s u e t echn ique . F o r Scots p ine and N o r w a y s p r u c e , c e l l u l o s e content was lowest i n the m i d d l e l a m e l l a (M) and p r i m a r y w a l l (P) l a y e r s (35%), but t h e r e -after i n c r e a s e d s t e a d i l y b y 15-20% o v e r the outer , m i d d l e , and i n n e r s e c o n d a r y w a l l (S , S , S ). A c c o r d i n g to T i m e l l (135) this r e a f f i r m s e a r l i e r r e l a t i o n -J. L.r J ships noted b y A s u n m a a and L a n g e . In the M and P , a r a b i n a n , ga lac tan , and p e c t i c ac ids w e r e p r e s e n t i n the o r d e r of 50%; i n 1936, B a i l e y (9) showed M of Douglas f i r to conta in 14% pentosan . M e i e r (89) fur ther showed that g l u c o m a n n a n was c o n c e n t r a t e d i n the S^ and S^ (24 to 27%), whi le m o r e than h a l f the x y l a n was found i n the S^. S c h u e r c h (108) cites T h o m p s o n et a l . as h a v i n g shown that c a r b o x y l content i s h i g h n e a r the P and d e c r e a s e s l i n e a r l y a c r o s s the c e l l w a l l to the l u m e n . A c c o r d i n g to Stewart (118), T h o r n b e r and N o r t h c o t e s u b d i v i d e d n o n - c e l l u l o s i c p o l y s a c c h a r i d e s of the P w a l l of Scots p ine into p e c t i c and n o n - p e c t i c f r a c t i o n s . O f the p e c t i c f rac t ions (10 to 15%), o n e - h a l f was c o m p o s e d of m o n o s a c c h a r i d e uni t s , wi th the r e m a i n d e r be ing u r o n i c a c i d uni ts ; the n o n - p e c t i c f r a c t i o n v a r i e d f r o m 35 to 45% and conta ined a 4 : 1 ra t io of m o n o s a c c h a r i d e s to u r o n i c a c i d u n i t s . T h e S w a l l was a c c o m p a n i e d b y p o l y s a c c h a r i d e s conta in ing g lucose , x y l o s e , g l u c u r o n i c a c i d o r 4 - 0 - m e t h y l g l u c u r o n i c a c i d , ga lac tose , and m a n n o s e un i t s . T h e d i s t r i b u t i o n of l i g n i n t h r o u g h the c e l l w a l l of M o n t e r e y p ine has b e e n s tud ied m o s t t h o r o u g h l y b y W a r d r o p (143) and W a r d r o p and B l a n d (144); a l i g n i n o r i ts p r e c u r s o r is depos i t ed i n i t i a l l y i n the P w a l l n e a r the c e l l c o r n e r s ; d u r i n g the f o r m a t i o n of ( c e l l u l o s e ) l a y e r S^, l i g n i n a p p e a r s a long the i n t e r c e l l u l a r M l a y e r and, s u c c e s s i v e l y , i n the tangent ia l and then r a d i a l P w a l l s . T h e m a j o r i t y of l i g n i n i s depos i ted or appears d u r i n g o r after f o r m a t i o n of ( ce l lu lose ) l a y e r S^; at the s a m e t i m e , l a y e r s S^ and S^ b e c o m e l i g n i f i e d . D u r i n g these p h a s e s of l i g n i f i c a t i o n , l i g n i n cont inues to be depos i ted i n the i n t e r c e l l u l a r and outer l a y e r s of the c e l l w a l l . T h e f i r s t attempt at a quant i tat ive e s t imate of l i g n i n d i s t r i b u t i o n i n the c e l l w a l l was m a d e i n 1925 b y R i t t e r (100), who stated that 75% of the l i g n i n i n wood was l o c a t e d i n the M , with the r e m a i n d e r b e i n g i n the P + S l a y e r s . T h r e e y e a r s l a t e r , he m o d i f i e d this f inding to i m p l y equa l d i s -t r i b u t i o n between M and P + S, but i n 1934, r e v e r t e d to h i s f i r s t s tand. In 1936, B a i l e y (9) showed that the m i d d l e l a m e l l a t r u l y d id cons i s t of 71% l i g n i n and, i n 1954, a c c o r d i n g to F r e y - W y s s l i n g (44) L a n g e u s e d u l t r a -v io l e t s p e c t r o s c o p y to e s t a b l i s h that i n s p r u c e , 60 to 90% of the l i g n i n was p r e s e n t i n the M , with on ly 10-12% b e i n g i n the S l a y e r . D i s t r i b u t i o n throughout the la t t er a p p e a r e d to t a p e r off. F r e y - W y s s l i n g (44) c i tes R u c h and H e n g a r t n e r as h a v i n g shown l i g n i f i c a t i o n i n jute f i b r e s to be u n i f o r m throughout the S l a y e r w h i c h contains s l i g h t l y l e s s than h a l f as m u c h l i g n i n as the P l a y e r . T h e c o n c l u s i o n s of R i t t e r and L a n g e w e r e r e c e n t l y d i sputed b y B e r l y n and M a r k (15) who, b y l u c i d but s i m p l e r e a s o n i n g showed that m o s t of M and P is l i g n i n , but m o s t of l i g n i n i s not i n the M and P l a y e r s ! F r o m other p u b l i s h e d data, they c a l c u l a t e d l i g n i n content i n M to be somewhat l e s s than 40% of the tota l i n wood. T h e state of c e l l u l o s e aggrega t ion d i f fers c o n s i d e r a b l y f r o m that of the e n c r u s t i n g const i tuents: C e l l u l o s e m o l e c u l e s a r e aggregated into b i o -l o g i c a l units of s t r u c t u r e t e r m e d m i c r o f i b r i l s . F r o m the m a n y e l e c t r o n m i c r o s c o p e studies on these uni t s , F r e y - W y s s l i n g (43) has i n t e g r a t e d the i m p o r t a n t c o n c l u s i o n s into a un i fy ing concept of m i c r o f i b r i l s t r u c t u r e . o D i m e n s i o n s of each m i c r o f i b r i l a r e a p p r o x i m a t e l y 100 x 200 A , wi th in w h i c h four m i c e l l e s or c r y s t a l l i t e s a r e loca ted; the la t t er a r e about 30 x 70 I" i n c r o s s sec t ion , at l e a s t 600 A i n length, and a r e s u r r o u n d e d b y p a r a c r y s t a l l i n e m a t e r i a l which , when u n d e r g o i n g l i g n i n r e m o v a l , a p p a r e n t l y c r y s t a l l i z e s to g ive a s l ight i n c r e a s e i n m i c e l l e s i z e . A c c o r d i n g to F r e y - W y s s l i n g (44), the p h y s i c a l a s s o c i a t i o n of l i g n i n with c a r b o h y d r a t e s was f i r s t r e p o r t e d b y F r e y who showed that l i g n i n was 28 e n c r u s t e d i n an a m o r p h o u s state; th is was c o n f i r m e d b y F r e u d e n b e r g et a l . who found that, after quanti tat ive e x t r a c t i o n of c e l l u l o s e , l i g n i f i e d c e l l wa l l s y i e l d e d a f r a m e w o r k of a m o r p h o u s l i g n i n . A s t b u r y et a l . (7) have s tud ied the p h y s i c a l r e l a t i o n s h i p between m i c r o f i b r i l s and a s s o c i a t e d c e l l w a l l c o n -st i tuents and, a c c o r d i n g to W a r d r o p and B l a n d (144), P r e s t o n and A l l s o p showed that the X - r a y d i f f r a c t i o n d i a g r a m of c o i r changed l i t t l e upon l i g n i n r e m o v a l , l e a d i n g to the c o n c l u s i o n that l i g n i n d id not penetrate the m i c r o f i b r i l s . H o d g e and W a r d r o p (58) ,obtained d i r e c t ev idence of l i g n i n p e n e t r a t i o n between c r y s t a l l i n e r e g i o n s of m i c r o f i b r i l s ; they r e p o r t e d that, after de l i gn i f i ca t ion , m i c r o f i b r i l s (perhaps m i c e l l e s ) 50-100 R. i n d i a m e t e r cou ld be seen with m u c h g r e a t e r c l a r i t y . C o p p i c k and F o w l e r (31) s tud ied a c o l d soda pulp of A u s t r a l i a n m o u n t a i n ash ( E u c a l y p t u s regnans F . M u e l l . ) d u r i n g the e a r l y stage of d e l i g n i f i c a t i o n and found l i g n i n s t i l l a d h e r i n g to the m i c r o f i b r i l s u r f a c e s . T h e a m o r p h o u s qua l i ty of l i g n i n r e s i d u e s has b e e n noted b y M f i i l e t h a l e r (92) who i n v e s t i g a t e d the l i g n i n s t r u c t u r e of s i s a l after c e l l w a l l s a c c h a r i f i c a t i o n wi th s u l f u r i c a c i d ; he o b s e r v e d the p r e s e n c e of minute p o r e s (250-40 OA- i n d i a m e t e r ) w h i c h w e r e thought to be f o r m e d when the c e l l u l o s e m i c r o f i b r i l s w e r e d i s s o l v e d . Mtthlethaler t h e r e f o r e c o n c l u d e d that c e l l u l o s e and n o n - c e l l u l o s e each f o r m independent , but i n t e r p e n e t r a t i n g s y s t e m s . F r o m a c r o s s - s e c t i o n of T a s m a n i a n m y r t l e (Nothofagus cunning -h a m i i , O e r s t . )j W a r d r o p and B l a n d (144) i l l u s t r a t e d s i m i l a r f indings to this , not ing the p r e s e n c e of p o r e s 200 to 300 & wide i n r e s i d u a l l i g n i n . A s with M u h l e t h a l e r ' s o b s e r v a t i o n s , these p o r e s c o u l d be expected to be l a r g e r than the m i c r o f i b r i l s b e c a u s e of the s w e l l i n g of c e l l u l o s e and r e m o v a l of p a r a -c r y s t a l l i n e a r e a s d u r i n g so lut ion . A p p r o x i m a t e l y 40 y e a r s after F r e y ' s work , F r e y - W y s s l i n g (44) r e p e a t e d the e x p e r i m e n t s of F r e u d e n b e r g et a l . and p r o d u c e d ' l i g n i n ghosts" of r a d i a l c e l l wal l s of s p r u c e t r a c h e i d s b y d i s s o l v i n g the c a r b o h y d r a t e s with c u o x a m , l e a v i n g the p r o o u s ske le ton of l i g n i n as a "rodlet c o m p o s i t e " body . T h i s suggests that i f a ( l ignin); cement i s added to a w e l l - o r i e n t e d s t r u c t u r e ( ce l lu lo se ) ;and the la t t er r e m o v e d , the c e m e n t w i l l then r e t a i n its o r i g i n a l s t r u c t u r e and t h e r e b y the b i r e f r i n g e n c e of i ts r e f l e c t i n g s u r f a c e l eaves a ghost i m a g e of the o r i g i n a l s t r u c t u r e , c e l l u l o s e . E . B i o s y n t h e s i s W h i l e knowledge of wood b i o s y n t h e s i s i s r a t h e r m e a g r e i n s o m e r e s p e c t s , m u c h u s e f u l i n f o r m a t i o n i s , however , a v a i l a b l e . A l t h o u g h m u c h i s known about o r i g i n of s u g a r s i n p lants , r e l a t i v e l y l i t t l e i s a v a i l a b l e on c a r b o h y d r a t e m e t a b o l i s m i n t r e e s , hence , m o s t suggested m e t a b o l i c p a t h -ways r e s u l t f r o m ana logy with known s o u r c e s i n plants a n d / o r fungi . R e g a r d l e s s of t h e i r apparent p h y s i c a l and c h e m i c a l d i f f erences , g lucose and l i g n i n have a c o m m o n o r i g i n , n a m e l y c a r b o n diox ide (73); the m e c h a n -i s m of c o n v e r s i o n to s u g a r s and p o l y m e r s has been s tudied b y m a n y w o r k e r s . Jones (66) has shown that m o s t hexose s u g a r s a r i s e i n the fo l lowing way: 3 - D - p h o s p h o g l y c e r o n i c a c i d (the f i r s t p r o d u c t of photosynthes i s ) i s sp l i t off f r o m a D - e r y t h r o p e n t u l o s e diphosphate d e r i v a t i v e and, with the e n z y m e a ldo lase , condenses wi th a 3 - D - p h o s p h o g l y c e r a l d e h y d e o r other t r i o s e f r a g m e n t to y i e l d D - f r u c t o s e - 1, 6 - d iphosphate . T h i s m a y then be c o n -v e r t e d to pentose s u g a r s t h r o u g h at l ea s t 3 pathways (66). Jones (66) c i tes K r o t k o v et a l . as showing that, b e s i d e s conta in ing m a i n l y n o n - r e d u c i n g hexoses , photosynthates of e a s t e r n white p ine (P inus s t robus L . ) seed l ings conta in s m a l l amounts of s h i k i m i c and qu in ic a c i d s ; these a r e known to be i m p o r t a n t l i g n i n p r e c u r s o r s . F r o m this and other ev idence , Jones (66) has shown that f o r m a t i o n of l i g n i n p r e c u r s o r s r e q u i r e s the s a m e unit as that u s e d for hexose sugar synthes i s , n a m e l y , 3 - D - p h o s p h o g l y c e r o n i c a c i d (A) . W h e n condensed with D - e r y t h r o s e - 4 - phosphate , it f o r m s 3. - deoxy - 2 -keto - D - a r a b i n o h e x u l o s o n i c a c i d - 7 - phosphate w h i c h then undergoes coup led r e a c t i o n s (73) with (A) to f o r m s h i k i m i c and p r e p h e n i c ac ids (66, 107). H e n c e , i n addi t ion to b e i n g i n v o l v e d i n c e l l u l o s e synthes i s , (A) i s i n v o l v e d i n s e v e r a l stages of l i g n i n b i o s y n t h e s i s . C o l v i n (30) has g iven the fo l lowing r e s u m e of c e l l u l o s e b i o s y n t h e s i s s t a r t i n g where Jones ended: g lucose i s ac t iva ted i n t r a c e l l u l a r l y through g lucose - 1 - phosphate ( G - 1 - P) to u r i d i n e d i p h o s p h a t e g lucose ( U D P G ) and t r a n s f e r r e d to a l o n g - c h a i n p o l y h y d r o x y a l c o h o l to f o r m a l i p i d -g lucosephosphate c o m p l e x . In p lants , this m i g r a t e s t h r o u g h the c y t o p l a s m i c m e m b r a n e into the p lant c e l l w a l l . T h e g lucose is t r a n s f e r r e d (by t r a n s -g lucos idase ) to the end of a c e l l u l o s e c h a i n wi th in the i n s o l u b l e , e l o n -gat ing m i c r o f i b r i l t ips ; the r e s u l t i n g p o l y m e r i z a t i o n and c r y s t a l i z a t i o n into the l a t t i c e a r e r e g a r d e d as s i m u l t a n e o u s . T h e l i p i d c a r r i e r then r e t u r n s to the c e l l m e m b r a n e for r e - u s e inaanother c y c l e . M i c r o f i b r i l o r i e n t a t i o n m a y be subject to any of t h r e e in f luences ; m e c h a n i c a l s t r a i n i n the p lant c e l l w a l l , l a t e r a l a s s o c i a t i o n with V a n der W a a l ' s f o r c e s , and d i r e c t i o n b y the p r o t o p l a s m . 31 S tewart (118) suggests two m e c h a n i s m s of c e l l u l o s e b i o s y n t h e s i s : It has been shown that the p o l y s a c c h a r i d e i s b u i l t up of the s tepwise l engthening of the n o n - r e d u c i n g ends of a p r i m e r , w h i c h acts as the a c c e p t o r m o l e c u l e . It i s p o s s i b l e that p r i m e r m o l e c u l e s of s a c c h a r i d e s a r e t r a n s l o c a t e d into a s t r u c t u r a l m o l d . . . w h e r e they act as a c c e p t o r s for g l u c o s y l donors s u c h as s u c r o s e , U D P G , o r B - l , 4 - l i n k e d g lucans . T h u s the i n d i v i d u a l cha ins of c e l l u l o s e m a y b u i l d up to a degree of p o l y m e r i z a t i o n of 10, 000 o r m o r e , adjacent , p a r a l l e l l y - o r i e n t e d chains p e r h a p s b e i n g o r g a n i z e d into c r y s t a l l i n e m i c e l l e s . T h e a l ternate m e c h a n i s m is that whi le . . . the a v e r a g e lengths of m o s t c e l l u l o s e m i c e l l e s a r e u s u a l l y wi th in the range o f 200-600 K, these va lues c o r r e s p o n d to a D P range of about 40-120 . It i s p o s s i b l e , t h e r e f o r e , that the p r i m e r m o l e c u l e s a r e f o r m e d wi th in th i s r a n g e . T h e y m a y then c r y s t a l l i z e into m i c e l l e s w h i c h , after b e i n g a l i gned i n the s t r u c t u r a l m o l d , a r e subjec ted to the ac t ion of e n z y m e s w h i c h kni t together i n d i v i d u a l cha ins of c e l l u l o s e between the m i c e l l e s with i n c o r p o r a t i o n of new units of g lucose where n e c e s s a r y . In out l in ing the b i o g e n e s i s of c e l l u l o s e , i t was e s t a b l i s h e d that s h i k i -m i c a c i d o r i g i n a t e d f r o m c a r b o h y d r a t e m a t e r i a l . N u m e r o u s w o r k e r s have shown l a b e l l e d s h i k i m i c a c i d to be c o n v e r t e d v i a p r e p h e n i c a c i d into a r o -m a t i c a m i n o a c i d s , of w h i c h two poo l s exist : one for pheny la lan ine and the other for t y r o s i n e . B y this method , N e i s h and c o - w o r k e r s (93) a l so have e s t a b l i s h e d that d e a m i n a t i o n of these a m i n o ac ids l eads to c i n n a m i c a c i d s , and that d e r i v a t i v e s of these ac ids ( c i n n a m i c a lcoho l s a n d / o r t h e i r g l u c o -s ides : D - c o n i f e r i n , p - c o u m a r i n , s y r i n g i n ) s e r v e as i n t e r m e d i a t e s i n the b i o s y n t h e s i s of a n u m b e r of p h e n o l i c metabo l i t e s p e c u l i a r to p lants , i . e . , l i g n i n , f lavonoids and c o u m a r i n s . W h i l e these a r e a l l p h e n y l p r o p a n o i d i n s t r u c t u r e , N e i s h caut ions that this shows on ly that l i g n i n can have a p h e n y l p r o p a n o i d o r i g i n , not that i t a c t u a l l y i s s u c h i n s t r u c t u r e . N e v e r t h -l e s s , s i m i l a r i t y i n o r i g i n and s t r u c t u r e i s , h o w e v e r , s t r o n g ev idence for the concept of p h e n y l p r o p a n o i d s t r u c t u r e i n l i g n i n . T h e m e c h a n i s m for c o n v e r s i o n of c i n n a m i c a c i d d e r i v a t i v e s to l i g n i n has b e e n d i s c u s s e d b y F r e u d e n b e r g (42) who u s e d N o r w a y s p r u c e as an e x a m p l e : T h e t h r e e c i n n a m i c a l coho l s a r r i v e at the c a m b i u m , p r e s u m -ably b y t r a n s l o c a t i o n , where they m a y pass out as ag lycones o r , m o s t f requent ly , c o m b i n e with U D P G to f o r m g lucos ides w h i c h a r e then s t o r e d . T h e g r e a t e r p e r c e n t a g e of c o n i f e r y l a l c o h o l , the m a j o r const i tuent , is p r e s e n t as the g l u c o s i d e c o n i f e r i n (41)* W h e n the g l u c o s i d e s do p a s s out f r o m the c a m b i u m to the i m m a t u r e ce l l s u n d e r g o i n g l i g n i f i c a t i o n (2 to 3 c e l l s f r o m the c a m b i u m ) they a r e h y d r o l y z e d to ag lycones b y ^ — g l u c o s i d a s e , a l o c a l i z e d e n z y m e . T h e ag lycones ( c i n n a m i c a l c o h o l s now) a r e i n t u r n a t tacked b y abundant dehydrogenase p r e s e n t (of w h i c h l a c c a s e and p e r o x i d a s e a r e two m a j o r s o u r c e s ) and c o n v e r t e d into l i g n i n . W h e n the c e l l wa l l s b e c o m e p lugged with l i g n i n , the c e l l i s m a t u r e . F r e u d e n b e r g (42) has a l so shown that con i fer l i g n i n has a m e t h o -d i c a l s t r u c t u r e : L i k e other p o l y m o l e c u l e s , i t i s d e r i v e d f r o m s ingle uni t s , i . e. , c i n n a m i c a l c o h o l s . T h e s e condense o r p o l y m e r i z e v i a m e s o -m e r i c f o r m s with d i f ferent b o n d types at d i f ferent points of a t tachment and without definite sequence . T h r o u g h t h r e e m a j o r r e a c t i o n s , the p o l y -m o l e c u l e grows s i m u l t a n e o u s l y i n at l eas t three d i f ferent ways , consequent ly l i g n i n has a unique p o s i t i o n among h i g h p o l y m e r s , b e c a u s e other h igh p o l y m e r a r e f o r m e d b y one pathway. C o m m e n t i n g on the above a p p r o a c h to l i g n i f i c a t i o n , K r e m e r s (73) s a i d : In c o n f o r m i t y with the p r i n c i p l e that l i g n i n m u s t o r i g i n a t e with photosynthes i s p r o d u c t s , the b i o c h e m i c a l o r i g i n of c o n i f e r y l a l c o h o l has been r e l a t e d to the s i m p l e s u g a r s b y analogy to the m i c r o b i a l m e t a b o l i s m of g lucose v i a sedoheptulose , s h i k i m i c and p r e p h e n i c ac ids to p h e n y l a -lan ine and t y r o s i n e . B i o c h e m i c a l r e a c t i o n s w h i c h would c o n v e r t t y r o s i n e into c o n i f e r y l a l c o h o l v i a f e r u l i c a c i d appear analogous to m a n y t r a n s f o r m a t i o n s o c c u r r i n g i n r e s p i r a t i o n and c a r b o h y d r a t e syn thes i s . A s a whole , F r e u d e n b e r g ' s s c h e m e of l i g n i f i c a t i o n has m u c h appea l b e c a u s e m a n y steps a r e cons i s tent with the g e n e r a l i t i e s of p lant m e t a b o l i s m . 34 III. M e t h o d s for "Wood M i c r o - a n a l y s i s A . C a r b o h y d r a t e F r a c t i o n W o o d c a r b o h y d r a t e a n a l y s i s has e v o l v e d to the state w h e r e tota l p o l y s a c c h a r i d e m a t e r i a l s or f r a c t i o n s t h e r e o f (whether e m p i r i c a l l y d e -f ined o r not) have been p r e p a r e d . E x a m p l e s a r e f i r s t l y , the m a c r o h o l o c e l l u l o s e p r e p a r a t i o n s of V a n B e c k u m and R i t t e r (138) and W i s e et a l (153) and secondly , the c e l l u l o s e of C r o s s and B e v a n (22, 33). T h e ch ie f value of a h o l o c e l l u l o s e p r e p a r a t i o n i s that i t o f fers a beg inn ing m a t e r i a l for f u r t h e r r e s e a r c h ; it g ives u s e f u l i n f o r m a t i o n about the s t a r t i n g m a t e r i a l and a l lows a p p r o x i m a t e quanti tat ive and qual i ta t ive study of h e m -i c e l l u l o s i c f r a c t i o n s and i s o l a t i o n of p e c t i c m a t e r i a l s . D u r i n g the pas t two c e n t u r i e s , v a r i o u s c l a s s i c a l p r o c e d u r e s have b e e n deve loped for the i s o l a t i o n of c a r b o h y d r a t e s f r o m c e l l wa l l s of e x t r a c t i v e -free wood m e a l s . U p to the 1950's, a l l w e r e b a s e d on a two-s tage l i g n i n subst i tut ion and s o l u b l i z a t i o n u s i n g f ree ha logens , t h e i r ox ides o r o x y s a l t s . T h e f i r s t m e t h o d to i s o l a t e c e l l u l o s e to any degree was that of C r o s s and B e v a n (33, 122). T h i s r e q u i r e d t r e a t m e n t of m o i s t m e a l b y a l ternate c h l o r i n a t i o n at 2 5 - 3 0 ° C and e x t r a c t i o n with d i s t i l l e d water , 3% su l fur d i o -x ide so lut ion , water , then b o i l i n g 2% s o d i u m sul f i te . T h i s c y c l e was cont inued u n t i l the f ibrous m a t e r i a l showed a faint p ink t inge on fur ther addi t ion of s o d i u m sul f i te . T h e method , however , was not quantitat ive and conta ined a p p r o x i m a t e l y 80% of the tota l h o l o c e l l u l o s e (23), as at l ea s t 10% of the pentosans and 5% c > / _ - c e l l u l o s e w e r e r e m o v e d wi th the l i g n i n (123, 138). A c c o r d i n g to Wise_et al. (153), the f i r s t m e t h o d to i so la t e q u a n t i -t a t i v e l y both the c e l l u l o s e and h e m i c e l l u l o s e was that advanced b y S c h m i d t who, i n 1932, u s e d c h l o r i n e d iox ide , p y r i d i n e , and water . A l t h o u g h these reagents h a d p r a c t i c a l l y no effect on the c a r b o h y d r a t e s , h i s m e t h o d u n f o r t u n a t e l y r e q u i r e d one m o n t h for the i s o l a t i o n . In 1933, R i t t e r and K u r t h (103). e m p l o y e d a l ternate t r e a t m e n t of c h l o r i n e , a l c o h o l i c p y r i d i n e , and c o l d c a l c i u m h y p o c h l o r i t e on e x t r a c t i v e - f r e e wood m e a l . W h e n c o m p a r e d to S c h m i d t ' s p r o c e d u r e , they obta ined exce l l en t c o n f i r m a t i o n and subst i tuted the t e r m " h o l o c e l l u l o s e " for what S c h m i d t p r e v i o u s l y h a d c a l l e d "ske le t t substanzen", the r e a s o n b e i n g that the la t ter d i d not d e s c r i b e the m a t e r i a l c o r r e c t l y . H o w e v e r , th is m e t h o d needed r e f i n e m e n t as the t i m e r e q u i r e d for a n a l y s i s was two days and the u s e of p y r i d i n e was unpleasant (138)* In 1937, V a n B e c k u m and R i t t e r (138) m o d i f i e d this p r o c e d u r e to shor ten the i s o l a t i o n t i m e to t h r e e h r , t h e r e b y p r o v i d i n g a m e t h o d that i s s t i l l i n p o p u l a r use today (123) as i t r e m o v e s n e a r l y a l l the l i g n i n . T h e so lvent u s e d to d i s s o l v e the c h l o r o l i g n i n and n e u t r a l i z e h y d r o -c h l o r i c a c i d f o r m e d d u r i n g e h l o r i n a t i o n is hot e thano lamine , with a l ternate c h l o r i n a t i o n and e x t r a c t i o n m a d e u n t i l the r e s i d u e r e m a i n s u n c o l o u r e d on fur ther e x t r a c t i o n . T h e so lvent , i t se l f , has l i t t l e i f any act ion on the c a r b o h y d r a t e f r a c t i o n , but i n the aqueous condi t ion , as when fo l lowed with water e x t r a c t i o n , the so lvent tends to r e m o v e s m a l l amounts of c a r b o h y d r a t e and b e c o m e a b s o r b e d b y the h o l o c e l l u l o s e i t s e l f (153)* In addi t ion , c h l o r i n a t i o n causes o v e r h e a t i n g of the m e a l , consequent ly p o l y -s a c c h a r i d e d e g r a d a t i o n and h y d r o l y s i s can be expected (23). 36 Wise_et al_ (153) cite J a y m e as h a v i n g i n t r o d u c e d the use of s o d i u m c h l o r i t e with ace t i c a c i d as a p p l i e d to ex trac ted , m i c r o t o m e d wood s e c t i o n s . T h i s r e q u i r e d 12 h r for d e l i g n i f i c a t i o n and the r e s i d u e , un l ike c h l o r i n a t e d h o l o c e l l u l o s e , conta ined 3 to 5% l i g n i n w h i c h cou ld not be r e m o v e d without l o s s of attendant c a r b o h y d r a t e ; however , b e c a u s e of its s i m p l i c i t y and m i l d act ion on c e l l u l o s e and h e m i c e l l u l o s e , J a y m e 1 s m e t h o d was s tud ied i n t e n s -i v e l y b y W i s e et a l > (153) and m a r k e d i m p r o v e m e n t s have b e e n m a d e s i n c e . W i s e et_al(153) have b e e n able to r e d u c e r e a c t i o n t i m e b y t w o - t h i r d s and app ly this to a n a l y s i s of wood m e a l . C o n i f e r s a r e m o r e amenable to t h i s t r e a t m e n t than to c h l o r i n a t i o n . B r o w n i n g and B u b l i t z (23) found that the f o r e g o i n g m e t h o d p e r m i t t e d excess l o s s of c a r b o h y d r a t e s as d e l i g n i -f i c a t i o n a p p r o a c h e d c o m p l e t i o n . T h e y t h e r e f o r e u t i l i z e d the bes t f eatures of both the c h l o r i t e and c h l o r i n a t i o n p r o c e d u r e s to obta in be t t er pentosan, hence , h o l o c e l l u l o s e y i e l d than e i ther . In the s a m e a r t i c l e w r i t t e n i n 1951, they (23) m a d e an a p p r o p r i a t e r e s u m e of p r o g r e s s i n c e l l u l o s e i s o l a t i o n : T h e i s o l a t i o n of c e l l u l o s e p r e p a r a t i o n s f r o m wood b y d e l i gnif i cat ion wi th su i table reagents has b e e n c a r r i e d out for n e a r l y a century; i n e a r l y work , the d i f f e r -ent iat ion between the substance now des ignated "ce l lu lo se" and " h e m i c e l l u l o s e " was not c l e a r l y r e c o g n i z e d and p a r t of s u c h a na ture that extens ive h y d r o l y s i s and ox ida t ion of the c e l l u l o s e o c c u r r e d . A s a r e s u l t , the "ce l lu lo se" p r e p a r a t i o n s obta ined w e r e of a he terogeneous c h a r a c t e r and l i t t l e s i g n i f i c a n c e c o u l d be at tached to a n a l y t i c a l f i g u r e s . R e c e n t l y , t h e r e has b e e n a need for m i c r o - p r o c e d u r e s b a s e d on a wood m e a l s a m p l e s i ze l e s s than 1 g; four s u c h p r o c e d u r e s have been advanced , a l l d e r i v e f r o m u s i n g s c a l e d - d o w n v e r s i o n s of the m o r e p o p u l a r , though h i g h l y v a r i a b l e m a c r o - m e t h o d s . Z o b e l and M c E l w e e (160) d e t e r m i n e h o l o c e l l u l o s e and < ^ - c e l l u l o s e y ie lds on 0. 75 g p o r t i o n s of wood m e a l and found va lues to be h igh b y 1 to 2%, due to the m i l d m e t h o d of i s o l a t i o n . T h o u g h this m e t h o d gave r e p r o d u c a b l e r e s u l t s with a r e p l i c a t i o n n u m b e r of two, it d i d not appear to be under s t a t i s t i c a l c o n t r o l . E r i c k s o n (38) u s e d a m u l t i s a m p l e s y s t e m e m p l o y i n g 0. 5 g s a m p l e s i n w h i c h e x t r a c t i o n and c h l o r i t e h o l o c e l l u l o s e t r e a t m e n t s w e r e p e r f o r m e d without t r a n s f e r of s a m p l e s . H o w e v e r , whi le great c a r e was taken to study s u c h effects as t e m p e r a t u r e , p a r t i c l e s i ze , e x t r a c t i o n p r o c e d u r e , and p H , no s t a t i s t i c a l v e r i f i c a t i o n was evident as cho ice of s a m p l e s i ze a p p e a r e d to be a r b i t r a r y and no r e p l i c a t i o n was s t ipu la ted . W a t s o n (146) has a p p l i e d the m e t h o d of C r o s s and B e v a n to 0. 5 g s a m p l e s of M o n t e r e y p i n e . O f 50 s a m p l e s h a v i n g two r e p l i c a t i o n s , 43 w e r e wi th in 1% of each o ther . T h i s does not const i tute s t a t i s t i c a l v a l i d i t y . U s i n g weights be low 0. 4 g, however , e r r o r i n c r e a s e d s i g n i f i c a n t l y . L e o p o l d (77) has r e p o r t e d the p r e p a r a t i o n of h o l o c e l l u l o s e f ibres f r o m l o b l o l l y p ine , but f a i l e d to ind ica te s a m p l e s i ze o r r e p l i c a t e s . T h o u g h s t a t i s t i c a l c o n t r o l i s l a c k i n g to a v a r i a b l e degree i n a l l these methods , t h e i r g r e a t d isadvantage i s t h e i r l a r g e s a m p l e s i z e and the h igh r e p l i c a t i o n n u m b e r that i s o b v i o u s l y needed with the m a c r o p r o c e d u r e s upon w h i c h they r e l y . A l s o , c o r r e c t i o n for r e s i d u a l l i g n i n was absent. A di f ferent , fifth s e m i - m i c r o m e t h o d has b e e n u s e d b y M e i e r (89) and M e i e r and W i l k i e (90) i n w h i c h s e c o n d a r y x y l a r y f i b r e s a r e h y d r o l y z e d to t h e i r m o n o s a c c h a r i d e s , f r o m which the p o l y s a c c h a r i d e c o m p o s i t i o n i s c a l c u l a t e d f r o m s o m e b a s i c a s s u m p t i o n s and c h r o m a t o g r a p h i c e v i d e n c e . 38 L a r s o n (76) has a lso u s e d a s i m i l a r m e t h o d for c a l c u l a t i n g p o l y s a c c h a r i d e c o m p o s i t i o n . W h i l e both methods have appea l , i t i s p r o b a b l e that they a r e on ly p r o x i m a t e ; s i n c e r e c o n s t r u c t i o n i n v o l v e s a s s u m p t i o n of p o l y s a c c h a r i d e c o m p o s i t i o n f r o m t h e i r h y d r o l y s i s p r o d u c t s and not d i r e c t e x p e r i m e n t a l ev idence a lone, a degree of u n c e r t a i n t y i s i n t r o d u c e d . A b o u t 1940, r e s e a r c h e r s w e r e t u r n i n g t h e i r attention f r o m i m p e r f e c t c a r b o h y d r a t e i s o l a t i o n to the ac t ion of n i t r i c a c i d on wood. A s w e l l as subst i tut ing and s o l u b l i z i n g the l i g n i n , n i t r i c a c i d f o r m s a c e l l u l o s e n i t r a t e e s ter d e r i v a t i v e w h i c h can be u s e d for y i e l d and m o l e c u l a r weight d e t e r m i n -at ion. J a h n and C o p p i c k (64) r e p o r t e d that n i t r a t i o n of woody t i s s u e s with f u m i n g n i t r i c a c i d was f i r s t done i n 1937 b y F r i e s e and F u r s t who n i t r a t e d a " s p r u c e " and " r e d b e e c h " i n E u r o p e . T h e y u s e d n i t r i c a c i d m i x e d with s u l f u r i c or p h o s p h o r i c ac ids and r e p o r t e d a 50% s o l u b l i z a t i o n of s p r u c e (hence, a s o l i d r e s i d u e of u n d e r 50%). J a h n and C o p p i c k (64) then d i d a f e a s i b i l i t y study to d e t e r m i n e whether or not woody t i s s u e s i n g e n e r a l c o u l d be n i t r a t e d to y i e l d p r o d u c t s of p o s s i b l e p r a c t i c a l o r s c i e n t i f i c v a l u e . B e s i d e s t h r e e p u l p s , e ight woods w e r e s tud ied s u c c e s s f u l l y u s i n g a r a t h e r c r u d e p r o c e d u r e ; a s u l f u r i c - n i t r i c a c i d m i x t u r e at 1 0 ° C was p o u r e d onto a i r - d r y , 60-80 m e s h , u n e x t r a c t e d wood m e a l and m a i n t a i n e d at 1 0 ° C for f ive h o u r s after w h i c h the p r o d u c t was d r o w n e d i n i c e water , b l e a c h e d , and d r i e d . P r o p e r t i e s of the n i t r a t e i n c l u d e d a 90% acetone so lub i l i t y , 11% n i t r o -gen content, and a r a t h e r l o o s e l y def ined s p e c t r u m of m o l e c u l a r weights . C h a r a c t e r i s t i c a l l y , softwoods gave a h i g h e r y i e l d of n i t r a t e . T h e n i t r a t i o n p r o c e d u r e has s i n c e been r e f i n e d and s i m p l i f i e d b y T i m e l l (134) and A l e x a n d e r and M i t c h e l l (2); the l a t t e r deve loped a n i t r a t i n g m i x t u r e which , b y v i r t u e of i t s c a u s i n g m i n i m u m d e g r a d a t i o n and h igh degree of n i t r a t i o n , i s s t i l l u s e d today. In the late 1940's and e a r l y 1950's, work b y s e v e r a l N o r w e g i a n s show that the ©4 - c e l l u l o s e f r a c t i o n of wood pulps c o u l d be obta ined r e l i a b l y b y n i t r a t i o n . T i m e l l (130) r e p o r t e d that B r y d e p i o n e e r e d this a p p r o a c h and l a t e r , B r y d e and S m i t h (25) r e c o v e r e d 45% of a s e m i - c h e m i c a l pulp h a v i n g an i n t r i n s i c v i s c o s i t y of 36 d l / g . A b a d i e and E l l e f s e n (1) then c o m p a r e d - v a n d c e l l u l o s e n i t r a t e (hereaf ter "n i t roce l lu lo se") y i e l d s of h y d r o l y z e d cotton and i n d u s t r i a l pulps between the range of 50 to 98% f r o m 26 p a i r s of v a l u e s . T h e y showed a c o r r e l a t i o n coef f ic ient of 0 .99 and r e g r e s s i o n coef f ic ient of 0 .98 , d e m o n s t r a t i n g n e a r l y i d e n t i c a l quanti tat ive c o r r e s p o n d e n c e . F u r t h e r m o r e , they found qual i ta t ive c o r r e s -pondence b y e x a m i n i n g the degree of p o l y m e r i z a t i o n ; they c o n c l u d e d f r o m both a p p r o a c h e s that the n i t r o c e l l u l o s e f r o m pulp was n i t r a t e d e»^- c e l l u l o s e . B r y d e et a l . (24) showed a s i m i l a r c o r r e l a t i o n i n o ther c o m m e r c i a l pu lps and a l so found that s a m p l e s as s m a l l as 0. 2 g c o u l d be u s e d . T i m e l l (129) has i n v e s t i g a t e d the c h e m i c a l p u r i t y of white s p r u c e ( P i c e a g l a u c a ( M o e n c h . ) V o s s ) n i t r o c e l l u l o s e as w e l l as its cha in length and p o l y d i s p e r s i ty . H e found c h l o r i t e o< - c e l l u l o s e and m a x i m u m n i t r o -c e l l u l o s e y i e lds to agree c l o s e l y ( i . e. , 50 and 49%, r e s p e c t i v e l y ) and that on c h r o m a t o g r a p h i c a n a l y s i s , both conta ined g lucose , m a n n o s e , x y l o s e , and u r o n i c a c i d r e s i d u e s . T i m e l l c o n c l u d e d that both methods account for v e r y s i m i l a r p o r t i o n s of wood, although ne i ther y i e l d "true" c e l l u l o s e . S n y d e r and T i m e l l ( l l l ) s i m i l a r l y i n v e s t i g a t e d P a c i f i c s i l v e r f i r ( A b i e s  b a l s a m e a L . , M i l l . ) and showed c h l o r i t e o ^ - c e l l u l o s e and m a x i m u m n i t r o c e l l u l o s e y i e lds of 48% and 49%, r e s p e c t i v e l y . T h e n i t r o c e l l u l o s e p r o d u c t conta ined g lucose (88%), m a n n o s e (9%) and x y l o s e (1%) r e s i d u e s whi le , s u r p r i s i n g l y , both the w a t e r - a c e t o n e and m e t h a n o l - s o l u b l e p o r t i o n s conta ined g lucose and m a n n o s e r e s i d u e s . T i m e l l (130) f i n a l l y c o m p a r e d p r o d u c t s f r o m both methods of c e l l u l o s e r e c o v e r y for four addi t iona l c o n i f e r s ; each gave c e l l u l o s e va lues that agreed , r a n g i n g i n y i e l d f r o m 40 to 45%. T i m e l l a lso found that the s m a l l e r p o r t i o n of to ta l g lucomannans was o c c l u d e d i n the n i t r o c e l l u l o s e . A l p h a - c e l l u l o s e contents for m o s t spec ie s a g r e e d with those r e p o r t e d p r e v i o u s l y (129) and d i f f erences between methods showed no m o r e v a r i a t i o n than those o b s e r v e d b y A b a d i e and E l l e f s e n (1). S t range ly , o n l y the la t t er authors i n d i c a t e d s o m e s e m b l a n c e of s t a t i s t i c a l r e l i a b i l i t y with r e g a r d to t e s t ing hypotheses and s a m p l i n g technique . A s is c u s t o m a r y with wood c h e m i s t s , the r e m a i n d e r appear to have n e g l e c t e d r e l i a b i l i t y c r i t e r i a a l together . S ince Staudinger , as r e p o r t e d b y S t a m m (115), and K r a e m e r (72) f i r s t d e v e l o p e d e m p i r i c a l equations r e l a t i n g v i s c o s i t y of h igh m o l e c u l a r weight p o l y m e r s to D P , n i t r o c e l l u l o s e has been u s e d as an a n a l y t i c a l too l for v i s c o m e t r i c d e t e r m i n a t i o n of D P and m o l e c u l a r weight i n wood and wood pu~ips ; this has b e e n i ts m o s t p o p u l a r a p p l i c a t i o n . H o w e v e r , A b a d i e and E l l e f s e n (1) have u t i l i z e d n i t r o c e l l u l o s e to d e m o n s t r a t e both qual i ta t ive and quanti tat ive s i m i l a r i t y with d - c e l l u l o s e f r o m pulp and, after conduct ing s i m i l a r e x p e r i m e n t s on N o r t h A m e r i c a n c o n i f e r s , T i m e l l (130) has sugges ted the use of n i t r o c e l l u l o s e as an a l ternate m e t h o d for the i s o l a t i o n and e s t i m a t i o n of - c e l l u l o s e i n wood. In addit ion, this d e r i v a t i v e has b e e n u s e d to s tudy c h a i n - l e n g t h and p o l y d i s p e r s i t y of v a r i o u s pulp spec ies i n S c a n d i n a v i a and N o r t h A m e r i c a . B r y d e et a l . (24) found the m e t h o d e s p e c i a l l y su i t ed to the study of d iges t ion p r o c e s s e s at v a r i o u s stages of de l ign i f i ca t ion; s i n c e the l i g n i n was r e m o v e d it d id not i n t e r f e r e with m e a s u r e m e n t s . H e n c e , these d i v e r s i f i e d app l i ca t ions , ind ica te that n i t r o -c e l l u l o s e m a y be e m p l o y e d as a u s e f u l and i m p o r t a n t a n a l y t i c a l too l i n wood and c e l l u l o s e s c i e n c e . In c o n s i d e r i n g the m e c h a n i s m of n i t r o c e l l u l o s e f o r m a t i o n , i t i s i m p o r t a n t to b e a r i n m i n d that c e l l u l o s e i s a f ibrous m a t e r i a l that m a y be c o n s i d e r e d at s e v e r a l l e v e l s of or i en ta t ion , depending on the i n v e s t i g a t o r and the ques t ion h i s a n a l y s i s i s meant to a n s w e r . One m a y p r o g r e s s f r o m the s u b - m a c r o s c o p i c l e v e l of the p lant c e l l t h r o u g h the f i b r i l l a r and m i c r o -f i b r i l l a r s u b m i c r o s c o p i c l e v e l s to the m i c e l l a r and, f ina l ly , the m o l e c u l a r stage of the c l a s s i c m o n o c l i n i c unit c e l l of M e y e r and M i s c h . B r i e f l y , this env i sages the unit c e l l for nat ive c e l l u l o s e as conta in ing five c e l l o b i o s e units p o s i t i o n e d i n such a way that d i s tances between atoms of the d i f ferent chains d e t e r m i n e the n a t u r e of the f o r c e s h o l d i n g the c e l l u l o s e la t t i ce g l u c o p y r a n o s e units hav ing one p r i m a r y and two s e c o n d a r y h y d r o x y l s p e r r i n g . It i s t h e r e f o r e c l e a r that, i n f o r m a t i o n of any c e l l u l o s e d e r i v a t i v e , together (63, 87). E a c h cha in , of c o u r s e , c o m p r i s e s m a n y 42 the p r o b l e m of h y d r o x y l a c c e s s i b i l i t y i s an i m p o r t a n t one. In o r d e r to c o m p r e h e n d c e l l u l o s e r e a c t i o n s , however , one m u s t b e g i n at the s u b m i c r o s c o p i c l e v e l : h e r e , m i c r o f i b r i l s are p r o p o s e d as cons i s t ing of aggregates of c e l l u l o s e chains ( m i c e l l e s ) p a s s i n g through o r d e r e d ( c r y s t a l l i n e ) and d i s o r d e r e d (amorphous ) r e g i o n s . If a reagent penetra tes between m i c r o f i b r i l s into a m o r p h o u s r e g i o n s , the extent and rate of r e a c t i o n i n c r e a s e s great ly ; how ever , the r e a c t i o n p r o d u c t w i l l be n o n - u n i f o r m , as no r e a c t i o n w i l l have o c c u r r e d with h y d r o x y l s of the c r y s t a l l i n e r e g i o n s . O n l y when the la t t er condi t ion i s f u l f i l l e d w i l l u n i f o r m i t y re su l t , hence , i n f o r m a t i o n of c e l l u l o s e d e r i v a t i v e s , it i s i m p o r t a n t that a l l c e l l u l o s e h y d r o x y l s a r e ava i lab le for r e a c t i o n (63). B e s i d e s this effect of s u p e r m o l e c u l a r s t r u c t u r e on subst i tuent d i s t r i b u t i o n , two other f a c t o r s m u s t be c o n s i d e r e d , the c e l l u l o s e l i n e a r p o l y m e r i c n a t u r e and the h y d r o x y l p r o p e r t i e s . T h e l o n g chain na ture of c e l l u l o s e m a k e s i t i m p o r t a n t that r e a c t i o n s o c c u r a long the c h a i n i n o r d e r to p r o d u c e a homogeneous end p r o d u c t ; r e c e n t w o r k (63) has shown m o s t c e l l u l o s e r e a c t i o n s ( inc lud ing "nitrat ion") to be p e r m u t o i d , i . e . , a l l h y d r o x y l s a r e c o m p l e t e l y a c c e s s i b l e . T h i s has the o v e r a l l effect of m a k i n g the r e a c t i o n p r o c e e d h o m o g e n e o u s l y . W h e n a l l h y d r o x y l s a r e a s s u m e d to be a c c e s s i b l e and equa l ly r e a c t i v e , the d i s t r i b u t i o n of subst i tuents with m e a n degree of subst i tut ion (D S) can be p r e d i c t e d . S p u r l i n (112) showed that a c e l l u l o s e d e r i v a t i v e hav ing an i n t e r m e d i a t e o v e r a l l degree of subst i tut ion always contains a c e r t a i n amount of unsubst i tuted , mono , d i - and t r i - s u b s t i t u t e d a n h y d r o g l u c o s e uni ts , 43 w h e r e a s one with a h i g h D S (2. 7 to 3. 0) c l o s e l y a p p r o a c h e s homogene i ty . H e a l so showed that d i f f erences i n h y d r o x y l r e a c t i v i t y (which a r e sl ight) d i d not g r e a t l y affect the o v e r a l l subst i tuent d i s t r i b u t i o n I H e n c e , the la t t er i s of r e l a t i v e l y m i n o r i m p o r t a n c e . In o r d e r to b r i n g c e l l u l o s e h y d r o x y l s into contact with a reagent , h y d r o g e n bonds m u s t be b r o k e n to a l low e n t r y of the swe l l ing agent. In the case of n i t r a t i o n , this causes l i m i t e d i n t r a - c r y s t a l l i n e s w e l l i n g c h a r a c -t e r i s t i c of a new la t t i ce to give a new, w e l l - d e f i n e d X - r a y d i a g r a m and al lows f o r m a t i o n of the w e l l - k n o w n addi t ion c o m p o u n d of K n e c h t . Such compounds a r e i m p o r t a n t i n that reagents can f r e e l y diffuse to enhance r e a c t i v i t y and this p r e d i s p o s e s f o r m a t i o n of m o r e or l e s s homogeneous d e r i v a t i v e s (63). T h e K n e c h t c o m p o u n d s e r v e s as the i n t e r m e d i a t e i n n i t r a t i o n of c e l l u l o s e wi th n i t r i c a c i d above 61%; concentra t ion; i n i ts f o r m a t i o n , X - r a y ev idence shows the c e l l u l o s e la t t i ce i s a t tacked and expanded m a i n l y i n one d i r e c t i o n . W h e r e a s the p e r i o d i c i t y along the b axis of the m o n o -c l i n i c c e l l i s u s u a l l y unchanged, the a and c d i m e n s i o n s i n c r e a s e (98). T h i s i s e x p l a i n e d b y an i n c r e a s e i n the (101) i n t e r p l a n a r d i s tance , but a l m o s t i d e n t i c a l (101) and (002) spac ings with those of c e l l u l o s e II (105). F r o m a c h e m i c a l point of v iew, the addi t ion c o m p o u n d f o r m s as fo l lows: when c e l l u l o s e i s t r e a t e d with c o n c e n t r a t e d n i t r i c a c i d , the h y d r o g e n bond between adjacent h y d r o x y l s i s d e s t r o y e d . T h i s i s r e p l a c e d b y a new bond f o r m e d between one h y d r o x y l , the h y d r o n i u m i o n of the reagent , and e i ther the oppos i te h y d r o x y l of the adjacent cha in d i r e c t l y 44 or t h r o u g h another m o l e c u l e o r i o n . H e n c e , one or m o r e oxygen atoms m a y f o r m a connect ing b r i d g e between h y d r o x y l s (105). A c o r r e c t amount of water i n the m i x e d a c i d i s i m p o r t a n t (2); enough m u s t be p r e s e n t to p e r m i t reagent i o n i z a t i o n , but not enough for compet i t i on between h y d r o x y l s and the water m o l e c u l e s for the h y d r o n i u m ions and, thus , p r e v e n t addition", c o m p o u n d f o r m a t i o n (63). When water i s p r e s e n t i n o p t i m u m quanti ty and h y d r o n i u m ions f o r m h y d r o g e n bonds , the counter ions with t h e i r water she l l s fo l low v i a e l e c t r o s t a t i c a t t r a c t i o n to cause la t t i ce expans ion and i n t e r m i c e l l a r swe l l ing (105). T h e c e l l u l o s e h y d r o x y l s a r e then capable of r e a c t i n g l ike o r d i n a r y a l iphat i c h y d r o x y l s to f o r m e s t e r s . N i t r a t i o n is c a r r i e d out i n a m e d i u m of cone n i t r i c a c i d , a s t r o n g l y a c i d i c swe l l ing agent ( s u l f u r i c , p h o s p h o r i c , o r ace t i c ac id) , and water . T h i s r e a c t i o n i s v e r y r a p i d and, s t r i c t l y , does not o c c u r with c e l l u l o s e i t se l f , but with the addi t ion c o m p o u n d . W h i l e the swe l l ing ac ids have s t rong aff ini ty for h y d r o x y l s , n i t r i c a c i d is o b v i o u s l y s u p e r i o r ; this m a y be due, i n p a r t , to the N0^ i o n h a v i n g a p l a n a r s t r u c t u r e whi le ions of s u l f u r i c and p h o s p h o r i c ac ids a r e not such , but a r e r a t h e r v o l u m i n o u s (91). Subst i tut ion o c c u r s wi th p r o d u c t i o n of a n i t ra te e s ter and n i t r i c a c i d - h y d r a t e m o l e c u l e ; with i n c r e a s e i n n i t r a t i o n t i m e , m o r e h y d r a t e i s p r o d u c e d and l e s s a c i d is a v a i l a b l e for n i t r a t i o n (91). In the m i c e l l a r r e g i o n s , the n i t r o g e n content of c e l l u l o s e is a net r e s u l t of two p r o c e s s e s : i n w a r d "di f fus ion" of f r e s h a c i d and o u t w a r d 'd i f fus ion" of "spent" a c i d (^ L. e . , n i t r i c a c i d - h y d r a t e ) . F o r l a c k of knowledge and the a p p r o p r i a t e t e r m , the e x p r e s s i o n "di f fus ion" i s u s e d b y M i l e s (91) to d e s c r i b e this p r o c e s s . T h e 45 f ina l s o l i d p r o d u c t i s not s i m p l y n i t r o c e l l u l o s e , but a n i t r o c e l l u l o s e - n i t r i c a c i d c o m p l e x . T h e above g ives a g e n e r a l u n d e r s t a n d i n g of the r e l a t i v e rate of n i t r a t i o n with t i m e : at f i r s t , n i t r o g e n content r i s e s r a p i d l y to a point wi th in 1% of the f ina l va lue , but s ince the rate d e c r e a s e s with t i m e , the f ina l i n t e r v a l i s p a s s e d on ly after a l ong p e r i o d . O t h e r factors a lso in f luence speed of n i t r a t i o n : a c i d v i s c o s i t y p a r a l l e l s n i t r a t i o n t i m e m a r k e d l y and with di lute ac ids and those of low n i t r o g e n content (see addi t ion c o m p o u n d format ion) n i t r a t i o n i s s low (91). T h e p r e s e n c e of a s w e l l i n g agent i s n e c e s s a r y as i t p r e s e r v e s the c e l l u l o s e f ibrous s t r u c t u r e and acts as a d e h y d r a t i n g agent on n i t r i c a c i d to f o r m the N O * ion; use of n i t r i c a c i d alone causes f ibres to ge la t in ize w h i c h i m p e d e s e s t e r i f i c a t i o n (46). N i t r a t i o n c a r r i e d out with s u l f u r i c a c i d ca ta lys t l eads m a i n l y to n i t r a t i o n ; i n c r e a s i n g the s u l f u r i c a c i d content and d e c r e a s i n g the water content (after o p t i m u m quantity) enhances su l fa t ion ( e s t e r i f i c a t i o n with s u l f u r i c ac id) , p r e v e n t i n g m a x i m u m n i t r a t i o n . T h i s i s a l l e v i a t e d b y u s i n g p h o s p h o r i c a c i d , an a c i d of l o w e r e l e c t r o p h i l i t y . B e i n g w e a k e r , it f o r m s l e s s phosphate e s ter as a s ide p r o d u c t ( r e s i d u a l p h o s p h o r u s content i s n e v e r m o r e than 0. 4%) (48), t h e r e f o r e , a h i g h e r n i t r o g e n content is at ta ined (e .g . 13. 9%) (2, 47); A l s o , i t i s thought to y i e l d a p r o d u c t of e s s e n t i a l l y the s a m e D P as that of the o r i g i n a l c e l l u l o s e (48), hence , it i s p a r t i c u l a r l y su i ted for d e t e r m i n a t i o n of plant and l i g n i f i e d m a t e r i a l s . T h o u g h ace t i c a n h y d r i d e g ives s l i g h t l y bet ter va lues , it cannot s w e l l and, hence , n i t ra te p lant c e l l u l o s e . 46 In s u m m a r y , m a x i m u m y i e l d of n i t r o c e l l u l o s e i s c o r r e l a t e d with that of c h l o r i t e - c e l l u l o s e to a h i g h l y s ign i f i cant degree e i ther when n o n - c o r -r e c t e d (1) or c o r r e c t e d (130) for n o n - g l u c a n m a t e r i a l . T h i s , of c o u r s e , p r e s u p p o s e s use of the o p t i m u m n i t r a t i n g m i x t u r e of A l e x a n d e r and M i t c h e l l (2) u s e d under n i t r a t i n g condi t ions ( e s tab l i shed for each spec ies ) as g iven by T i m e l l (134). T h e method cons i s t s of a r e l a t i v e l y n o n - d e g r a d a t i v e c o n v e r s i o n of c e l l u l o s e to a n i t r a t e d e r i v a t i v e , w h i c h m a y be p e r f o r m e d on s a m p l e s as s m a l l as 0. 2 g (24). B e s i d e s i n d i c a t i n g y i e l d , the m e t h o d w i l l a l low use of suff ic ient m a t e r i a l for subsequent a n a l y s i s . H e r e i n l i e s an i m p o r t a n t nove l ty that m i g h t a l low r e l i a b l e m e a s u r e m e n t s to be made on minute amounts of wood m a t e r i a l s wi th r e a s o n a b l e r e p l i c a t i o n n u m b e r . T h e m e t h o d c o u l d conta in u s e f u l features because of the s m a l l amount o f wood m a t e r i a l needed, a r e q u i r e m e n t w h i c h even the " s e m i - m i c r o 1 1 methods have f a i l e d to mee t . T h e r e i s no s i m p l e or s a t i s f a c t o r y m e t h o d for the a n a l y t i c a l d e t e r m i n a t i o n of c e l l u l o s e i n wood: after r e d u c i n g wood to a sui table p a r t i c l e s i ze , the p o l y s a c c h a r i d e f r a c t i o n m a y be e i ther e x t r a c t e d d i r e c t l y f r o m this o r the m e a l m a y be de l ign i f i ed b y a m i l d p r o c e d u r e to give h o l o c e l l u l o s e . T h e f o r m e r i s p o s s i b l e on ly i n a few c a s e s : a r a b i n o -ga lactans m a y be w a t e r - e x t r a c t e d (hence, t h e i r l o c a t i o n i n the c e l l w a l l i s quest ionable) and a p p r o x i m a t e l y h a l f the h e m i c e l l u l o s e s i n a n g i o s p e r m s m a y be e x t r a c t e d d i r e c t l y u s i n g 16% s o d i u m h y d r o x i d e . O t h e r than these i n s t a n c e s , de l i gnif i ca t ion i s n e c e s s a r y for a l l con i f erous woods . Idea l ly , s u c h an i s o l a t i o n seeks comple te l i g n i n r e m o v a l without l o s s of, or at tack on, the a s s o c i a t e d p o l y s a c c h a r i d e component s . E x p e r i m e n t a l l y , this i s d i f f icul t to ach ieve and no p r o c e d u r e has yet b e e n d e v i s e d to mee t this a i m without a t tacking the p o l y s a c c h a r i d e s . A l t h o u g h i n d i s p e n s i b l e for f u r t h e r i n g knowledge of wood c h e m i s t r y , p r e s e n t methods have a lso c a u s e d m u c h confus ion . Such a n a l y t i c a l p r o c e d u r e s a r e at bes t e m p i r i c a l l y u s e f u l for i s o l a t i n g groups of r e l a t e d subs tances , r a t h e r than s ing le m o l e c u l a r s p e c i e s . T h e p r o d u c t r e s u l t i n g f r o m the ac t ion of fuming n i t r i c a c i d on wood, h o w e v e r , has been shown b y T i m e l l (130) and A b a d i e and E l l e f s e n (1) to c l o s e l y a p p r o x i m a t e cxi - c e l l u l o s e content. M o r e o v e r , i n f o r m i n g this d e r i v a t i v e , the l i g n i n i s subst i tuted, then s o l u b l i z e d ; the net r e s u l t i s that t h r e e i m p o r t a n t changes have o c c u r r e d wi th l e s s degradat ion than e n c o u n t e r e d wi th the convent iona l two stage l i g n i n i s o l a t i o n p r o c e d u r e . F u r t h e r , the d e r i v a t i v e has double use fu lness for e s t i m a t i o n of o< - c e l lu lo s y i e l d and m o l e c u l a r weight (or D P) d e t e r m i n a t i o n . B e c a u s e of i ts p o l y m o l e c u l a r na ture , hence , p o l y d i s p e r s i t y , the d i s t r i b u t i o n of c e l l u l o s e m o l e c u l a r weights (or that of i ts d e r i v a t i v e s ) i s of i n t e r e s t to p h y s i c a l c h e m i s t s . T h e methods m o s t c o m m o n l y e m p l o y e d for d e t e r m i n a t i o n of the "d i f f erent ia l d i s t r i b u t i o n c u r v e " a r e those of f r a c t i o n a l p r e c i p i t a t i o n or so lut ion . T h e f o r m e r is a p p l i e d to c e l l u l o s e d e r i v a t i v e s i n so lut ion through addi t ion of a n o n - s o l v e n t , b y r e m o v a l of solvent , or b y addi t ion of so lvent n o n - s o l v e n t m i x t u r e s ; the net r e s u l t i s that p r e c i p i t a t e s o c c u r i n o r d e r of d e c r e a s i n g c h a i n - l e n g t h . T h e la t t er m e t h o d r e l i e s on the p r o g r e s s i v e e x t r a c t i o n of f rac t ions of i n c r e a s i n g c h a i n - l e n g t h f r o m u n d i s s o l v e d c e l l u l o s e d e r i v a t i v e s as the e x t r a c t i n g so lvent b e c o m e s a be t ter so lvent . 48 T h e fo l lowing studies with n i t r o c e l l u l o s e f r o m c o n i f e r s invo lve the use of f r a c t i o n a t i o n b y p r e c i p i t a t i o n . C o p p i c k and J a h n (32) n i t r a t e d s p r u c e and white p ine , and found that the v i s c o s i t y f r e q u e n c y c u r v e s for e a c h spec i e s c o n s i s t e d of two groups of m o l e c u l a r s i z e s . T h e f i r s t , m a i n l y c a r b o h y d r a t e i n na ture , h a d wide m o l e c u l a r weight d i s t r i b u t i o n of a s i z e c o m p a r a b l e to n i t r a t e d cotton l i n t e r s ; the second, c o m p o s e d of a p p r o x i -m a t e l y 5% of the a l c o h o l - e x t r a c t e d p r o d u c t , h a d a n a r r o w d i s t r i b u t i o n of low m o l e c u l a r weight, w h i c h p r o b a b l y r e p r e s e n t e d a m i x t u r e of l i g n i n d e g r a d a t i o n p r o d u c t s and n o n - c e l l u l o s i c m a t e r i a l s . T i m e l l (129) d e t e r m i n e d acetone was 33 d l / g u s i n g a C a n n o n - F e n s k e v i s c o m e t e r . F r e q u e n c y d i s t r i b u t i o n of D P showed two peaks wi th in a range of 1000 to 5500, one o c c u r r i n g at 1400 and c o r r e s p o n d i n g to 20% of the c e l l u l o s e , and the other o c c u r r i n g at 3100; among the n u m e r o u s spec ie s h a v i n g this two-peak c h a i n - l e n g t h d i s t r i b u t i o n a r e some s p r u c e s , w e s t e r n h e m l o c k , and Douglas f i r (129). A c c o r d i n g to T i m e l l (129), J o r g e n s e n has found a o n e - p e a k d i s t r i b u t i o n for b l a c k s p r u c e . M a n n o s e r e s i d u e s w e r e r a t h e r u n i f o r m l y d i s t r i b u t e d o v e r the ent i re range and l i t t l e d i f f erence showed, c h e m i c a l l y , between each peak. In P a c i f i c s i l v e r f i r , Snyder and T i m e l l (111) showed that the f r e q u e n c y d i s t r i b u t i o n of D P v a r i e d between 900 and 5500 and, as with white s p r u c e , two m a x i m a w e r e p r e s e n t : that at 1000 r e p r e s e n t e d 25% whi le the second, at 2500, r e p r e s e n t e d m o s t of the r e m a i n d e r . In l o c a t i o n and g e n e r a l na ture , this i s a l m o s t i d e n t i c a l to that obta ined for white s p r u c e (129) and p a p e r b i r c h ( B e t u l a p a p y r i f e r a M a r s h ) (137). that for white s p r u c e m a x i m u m of c e l l u l o s e n i t r a t e d i s s o l v e d i n M a x i m u m . |/(J of c e l l u l o s e n i t r a t e d i s s o l v e d i n acetone was 40 d l / g u s i n g a C a n n o n - F e n s k e v i s c o m e t e r ; th is i s h igher than the 33 d l / g quoted e l s e w h e r e for this spec i e s (129), the s o u r c e of this d i s c r e p a n c y b e i n g unknown. T h r o u g h o u t the f r e q u e n c y d i s t r i b u t i o n , l i t t l e c h e m i c a l d i f f erence was evident . M u c h i n f o r m a t i o n exis ts as to the nature and fine s t r u c t u r e of c e l l u l o s e i n s i tu . M a i n l y f r o m X - r a y s tudies , the s i ze and o r i e n t a t i o n of the m o n o c l i n i c uni t c e l l a r e known, as i s the a p p r o x i m a t e s i ze of c r y s t a l l i t e s and t h e i r r e g i o n s . B e c a u s e of the s o l i d c r y s t a l l i n e n a t u r e of c e l l u l o s e , however , i ts p o l y m e r i c or m o l e c u l a r p r o p e r t i e s cannot be s tud ied i n s i tu with p r e s e n t methods and, consequent ly , it m u s t be s o l u b l i z e d to d i s p e r s e i ts m o l e c u l e s . M a n y qual i ta t ive methods a r e a v a i l a b l e for c e l l u l o s e c h a r a c t e r i z a t i o n : o s m o t i c p r e s s u r e and sed imenta t ion e q u i l i b r i u m methods m a y give m o l e c u l a r weights o r D P d i r e c t l y ; a condi t ion for the la t ter i s the a s s u m p t i o n of the p r e s e n c e or absence of a definite l a t e r a l a s s o c i a t i o n of the s t r u c t u r a l chains (115); E n d - g r o u p and v i s c o s i t y methods give p r i m a r y - c h a i n lengths w h i c h m a y , i n t u r n , be c o n v e r t e d to m o l e c u l a r weights b y a s s u m i n g a degree of a s s o c i a t i o n (115). In conjunct ion with other m e a s u r e m e n t s d i f fus ion studies y i e l d m o l e c u l a r weight and shape f a c t o r s , and s p r e a d i n g m e a s u r e m e n t s , the m o l e c u l a r t h i c k n e s s e s . T h e p o l y - d i s p e r s i t y of c e l l u l o s e and i ts d e r i v a t i v e s affects s o m e m e a s u r e m e n t s d i f f erent ly : whi le v a r i o u s types of a v e r a g e can be c a l c u l a t e d f r o m sed imenta t ion e q u i l i b r i u m data, 50 v i s c o s i t y methods y i e l d w e i g h t - a v e r a g e m o l e c u l a r weights and o s m o t i c p r e s s u r e and end - group methods give those on a n u m b e r - a v e r a g e . F o r p o l y j d i s p e r s e m a t e r i a l s , the l a t t er g ives s m a l l e r a v e r a g e m o l e c u l a r weights . • W i t h the l i g h t - s c a t t e r i n g technique, w e i g h t - a v e r a g e m o l e c u l a r weights a r e d e t e r m i n e d along with i n f o r m a t i o n about the s i ze and shape of the p o l y m e r ; c e l l u l o s e solut ions undergo c o n s i d e r a b l e degradat ion , however , and absolute m e a s u r e s a r e i m p r a c t i c a l . U s e d with c e l l u l o s e d e r i v a t i v e s , though, the technique has b e e n s u c c e s s f u l on so lut ions of c e l l u l o s e n i t r a t e (8)* T h e u l t r a c e n t r i f u g e (120) m a y be u s e d to d e t e r m i n e not o n l y a v e r a g e m o l e c u l a r weight, but a l so m o l e c u l a r weight d i s t r i b u t i o n and s e d i m e n t a t i o n v e l o c i t y . E x p e r i m e n t a l l y , v i s c o s i t y m e a s u r e m e n t of a c e l l u l o s e so lut ion is the m o s t a v a i l a b l e and s i m p l e s t of the above methods , hence , i t has b e e n a p p l i e d e m p i r i c a l l y to gauge p lant p r o d u c t i o n c o n t r o l and effects of v a r i o u s c h e m i c a l t r e a t m e n t s on c e l l u l o s e , these be ing l a r g e l y fo l lowed and c o n t r o l l e d b y m e a s u r e m e n t s i n c u p r a m m o n i u m so lut ion (9 5). E v i d e n c e f r o m r e v e r s i b l e and degradat ive t r a n s f o r m a t i o n s between c e l l u l o s e and i ts c o m m o n d e r i v a t i v e s show both a r e d i s p e r s e d as s ing le cha ins ; s h o u l d they be a s s o c i a t e d , s u c h t r a n s f o r m a t i o n s wou ld be expected to a l ter the a s s o c i a t i o n (72). F u r t h e r , c e l l u l o s e and s u c h d e r i v a t i v e s i n di lute so lut ions with "good" so lvents are d i s p e r s e d i n units that r i g h t f u l l y m a y be r e g a r d e d as m o l e c u l e s (72, ) . L i n e a r p o l y m e r s ( l o n g - c h a i n m o l e c u l e s ) affect v i s c o s i t y to a far g r e a t e r extent than s p h e r i c a l p a r t i c l e s ; this effect i n c r e a s e s r a p i d l y with an i n c r e a s i n g m i n o r - m a j o r axis r a t i o . F o r r i g i d , r o d l i k e p o l y m e r s , no s i m p l e r e l a t i o n -ship ex i s t s between s p e c i f i c v i s c o s i t y , c o n c e n t r a t i o n and a x i a l r a t i o ; a so lu t ion is p o s s i b l e when B r o w n i a n m o t i o n i s e i ther so grea t as to negate o r i e n t a t i o n (e. g. s m a l l p a r t i c l e s ) or so s m a l l as to be n e g l i g i b l e (e. g. l a r g e p a r t i c l e s ) ; no so lut ion i s p o s s i b l e for i n t e r m e d i a t e cond i t i ons . M o s t r e l a t i o n s h i p s , h o w e v e r , i n v o l v e the square of m i n o r - m a j o r " r a t i o s a n d some a p p r o a c h c o n s i d e r i n g the effect ive p a r t i c l e v o l u m e equal to a sphere d e s c r i b e d b y the p a r t i c l e l ength as the d i a m e t e r (115). T o give a t r u e p i c t u r e of a h i g h p o l y m e r i n so lut ion , one would expect that, as r e f l e c t i n g i ts f l ex ib le n a t u r e , i ts v i s c o s i t y should be l e s s than that of r i g i d r o d s , but m o r e than that of a r a n d o m c o i l . T h a t th is i s the case has b e e n shown f r o m a r e l a t i o n between i n t r i n s i c v i s c o s i t y and m o l e c u l a r weight, the M a r k - H o u w i n k equat ion (34, 105): K 1 - K . Ma M M w h e r e : K , , , M a r e constants v a r y i n g M for so lvent and c e l l u l o s e d e r i v a t i v e = i n t r i n s i c v i s c o s i t y D P = degree of p o l y m e r i z a t i o n T h e exponent ,ta.n is a funct ion of the g e o m e t r y of the m o l e c u l e i n so lut ion; t h e o r e t i c a l l y , i ts va lue ranges f r o m 0. 5 for cha in m o l e c u l e s with u n r e s t r i c t e d ro ta t ion (a r a n d o m coi l ) to 1. 5 to 2 .0 for stiff, r o d l i k e m o l e -cu les ; c e l l u l o s e t r i n i t r a t e i n acetone has a va lue of 1.0, showing that such m o l e c u l e s i n so lut ion d i s p l a y f a i r l y - l o w f l ex ib i l i t y , although they a r e far f r o m r o d l i k e (105). T h e constants of this and other v i s c o s i t y equations a r e obta ined b y c o m p a r i s o n of v i s c o m e t r i c m e a s u r e m e n t s with one of the other m o l e c u l a r weight methods , e. g. u l t r a c e n t r i f u g a t i o n . T h e v i s c o s i t y method , then, m e r e l y e x p r e s s e s an e m p i r i c a l p r o p o r t i o n a l i t y ; i t i s not an absolute m e t h o d u s e d for m o l e c u l a r w e i g h t / D P d e t e r m i n a t i o n , but a s i m p l e m e a n s of fo l lowing such v a r i a t i o n s of m e m b e r s f r o m a p o l y m e r i c s e r i e s . C o m p a r e d to s t a n d a r d v i s c o s i t y methods , v i s c o s i t y of n i t r o c e l l u l o s e of fers these add i t iona l advantages: i t i s r a p i d and a c c u r a t e ( c o m p a r e the c u p r a m m o n i u m method); l i g n i n , be ing r e m o v e d f r o m the s t a r t i n g m a t e r i a l , does not i n t e r f e r e wi th m e a s u r e m e n t s ; and c h a i n - l e n g t h d e g r a d a t i o n is l e a s t ev ident . A p a r t f r o m the i n s t a b i l i t y of the n i t r a t e s when f o r m e d , the on ly f u r t h e r l i m i t a t i o n of consequence i s the need for deve lopment of a h i g h l y a c c u r a t e and p r e c i s e m e t h o d for e s t i m a t i o n of n i t r o g e n content, s ince v a r i a t i o n s i n th is w i l l m a r k e d l y affect v i s c o s i t y . B . O t h e r C o m p o n e n t s Methods a v a i l a b l e for m i c r o - a n a l y s i s of l i g n i n have b e e n r e v i e w e d r e c e n t l y b y "Wu and W i l s o n (157), whi le those for po lypheno l s and r e s i n s i n Douglas f i r a r e g iven i n p a p e r s b y S q u i r e et a l . (114) and C a m p b e l l et a l . (27), r e s p e c t i v e l y . M A T E R I A L S A N D M E T H O D S I. W o o d S a m p l e P r e p a r a t i o n A . S a m p l i n g C r i t e r i o n T h e c r i t e r i o n for s e l e c t i o n of wood m a t e r i a l s was b a s e d on a b r o a d b o t a n i c a l s o u r c e of wood t i s s u e s : thereby , r e su l t s f r o m the w o r k m i g h t be i n t e r p r e t e d o v e r a r e a s o n a b l e range and m o r e c l o s e l y a p p r o a c h a g e n e r a l s tatement . F r o m P i n a c e a e , s ix g e n e r a and seven spec ie s w e r e s a m p l e d ; these w e r e j a c k pine (P inus b a n k s i a n a ( L a m b . ) ), S i t k a s p r u c e ( P i c e a  s i t chens i s ( B o n g . ) C a r r . ) , b l a c k s p r u c e ( P i c e a m a r i a n a g ( M i l l . ) B . S .P . ) ), t a m a r a c k ( L a r i x l a r i c i n a (Du Roi) K . K o c h ) , Douglas f i r ( P s e u d o t s u g a  m e n z i e s i i ( M i r b . ) ; F r a n c o ) , w e s t e r n h e m l o c k ( T s u g a h e t e r o p h y l l a ( R a f j S a r g . ) , and P a c i f i c s i l v e r f i r ( A b i e s a m a b i l i s ( D o u g l . ) F o r b . ) . Woods f r o m two g e n e r a and spec i e s of C u p r e s s a c e a e were i n c l u d e d ; these w e r e w e s t e r n r e d c e d a r ( T h u j a p l i c a t a Donn) and ye l low c e d a r ( C h a m a e c y p a r i s n o o t k a -tens i s ( D . Don.) S p a c h . ); T h e en t i re s a m p l i n g p l a n i n c l u d e d two f a m i l i e s , eight g e n e r a , and nine spec i e s , with r e p l i c a t i o n between t r e e s for one spec i e s and r e p l i c a t i o n of m o r e than one i n c r e m e n t wi th in t r e e s for two s p e c i e s . O r i g i n and d e s c r i p t i o n of g r o s s wood c h a r a c t e r i s t i c s for s o m e of these wood s a m p l e s i s g iven i n A p p e n d i x III. B . P r e p a r a t i o n of W o o d M e a l s T h e g e n e r a l p r o c e d u r e for p r e p a r a t i o n of wood m e a l s was as fo l lows: i m m e d i a t e l y after f e l l ing , d i s c sec t ions w e r e r e m o v e d f r o m each s t e m at b r e a s t height , w r a p p e d i n po lye thy lene , and t r a n s f e r r e d to the W o o d S c i e n c e L a b o r a t o r y at the U n i v e r s i t y of B r i t i s h C o l u m b i a . F r o m these , r e c t a n -gu lar , s t r a i g h t - g r a i n e d s p e c i m e n b l o c k s £ 1 / 2 - i n (tangential) x 4 - i n ( longitudinal) x 2 - i n ( rad ia l ) ~] w e r e sp l i t f r o m the outer h e a r t w o o d or sapwood along the m a j o r and m i n o r axes and soaked i n water for s e v e r a l days . I n c r e m e n t s chosen r e p r e s e n t e d c h a r a c t e r i s t i c widths (2 to 3 m m ) for r e g u l a r m a t u r e wood i n the p a r t i c u l a r s t e m sect ions and for the s p e c i e s . A s W u and W i l s o n (157) point out, this i s a s t r o n g point of s a m p l i n g ; i n c o n t r a s t to f o r m e r w o r k on e x c i s e d e a r l y w o o d and latewood, this does not r e q u i r e a b n o r m a l l y w i d e - r i n g e d m a t e r i a l . B l o c k s w e r e m i c r o t o m e d i n the m a n n e r d e s c r i b e d b y Ifju (61), w h e r e b y e a c h s p e c i m e n was p l a c e d in the jaws of a s p e c i a l 6 - i n v i s e , a l igned, and t ightened so that the top growth r i n g p a r a l l e l l e d the b lade cutt ing edge. T h e p r e c e d i n g r i n g was s e c t i o n e d tangent ia l ly to a l low for m i n o r b l o c k adjustments i n the cutt ing p lane and the r e s u l t i n g e x t r a sec t ions w e r e u s e d to d e t e r m i n e n i t r a t i o n t i m e to m a x i m u m y i e l d ; between 25 to 35 sec t ions a v e r a g i n g lOO.^u t h i c k n e s s were r e m o v e d f r o m each i n c r e m e n t and n u m b e r e d i n d i v i d u a l l y with a l c o h o l - b e n z e n e so luble p e n c i l . T h e s e w e r e a i r -d r i e d and d i v i d e d into s i x equal groups a c c o r d i n g to s i x s equent ia l l y s p a c e d pos i t i ons a c r o s s the i n c r e m e n t f r o m e a r l y - to la tewood. A f t e r g r i n d i n g the sect ions t h r o u g h a W i l e y m i l l , s i e v i n g and c o l l e c t i n g a c e r t a i n m e s h f r a c t i o n to be d e s c r i b e d , 0. 5 to 1. 0 g p o r t i o n s of the wood m e a l s w e r e s e a l e d s e p a r a t e l y into s m a l l (1 1 / 2 - i n x 2- in) 1 0 0 - m e s h n y l o n o r g a n z a bags with a s o l d e r i n g gun. A l l bags w e r e g r o u p e d together and s u c c e s s i v e l y e x t r a c t e d . 55 A s the m a t e r i a l s h a d b e e n c o l l e c t e d and p r e p a r e d o v e r a 3 - y r i n t e r v a l , s l ight d i f f erences o c c u r r e d in s o m e aspects of p r e p a r a t i o n . In 1963, W u (156) s tud ied S i t k a s p r u c e , Douglas f i r , w e s t e r n h e m l o c k , P a c i f i c s i l v e r f i r , and w e s t e r n r e d c e d a r . Sect ions w e r e g r o u n d into m e a l u s i n g an i n t e r m e d i a t e W i l e y m i l l , c o l l e c t e d as the 40-80 m e s h f r a c t i o n , h o m o -genized , condi t ioned to s i m i l a r m o i s t u r e content, and s e a l e d u n d e r n i t r o g e n u n t i l u s e d for this s tudy. T h e other woods were c o l l e c t e d i n 1966, and, apar t f r o m the Douglas f i r s a m p l e f r o m I n c r e m e n t 40 (which was m i c r o -t o m e d two days after fe l l ing) , b l o c k sect ions w e r e s t o r e d i n the c o l d i n t h y m o l so lu t ions . F o l l o w i n g m i c r o t o m i n g , sect ions w e r e fed g r a d u a l l y through a v a r i a b l e speed m i c r o - W i l e y m i l l ( W i l e y - F . R . I . m i c r o model ) set at a p p r o x i m a t e l y 3500 r p m , and g r o u n d to pass a 2 0 - m e s h s c r e e n . T h e l a t t er two steps m i n i m i z e d f ines; on s c r e e n i n g , the 40-60 m e s h f r a c t i o n was r e t a i n e d whi le the o v e r s i z e p a r t i c l e s w e r e r e t u r n e d to the m i l l and r e g r o u n d to p a s s aga in the 2 0 - m e s h s c r e e n . B y this method , a i r - d r y wood m i c r o s e c t i o n s w e r e r e c o v e r e d in 75 to 80% y i e l d as 40-60 m e s h wood m e a l . T h e 40-60 m e s h f r a c t i o n s i ze was c h o s e n b e c a u s e p r e l i m i n a r y studies showed that for both e a r l y - and latewood, n i t r o c e l l u l o s e y i e l d r e a c h e s a m a x i m u m for this p a r t i c l e s i ze and i s l ea s t v a r i a b l e i n the range of p a r t i c l e s i z e between 8 0 - m e s h (0. 16 m m ) and 9 .0 m m . L i k e w i s e , T i m e l l (130) a l so r e c o v e r e d h i g h e r n i t r o c e l l u l o s e y ie lds with 40-60 m e s h white s p r u c e m e a l than with 60-80 m e s h wood m e a l . E a r l y s tudies also showed that the wood e x t r a c t i o n t r e a t m e n t in f luenced n i t r a t i o n . T h e p r o c e d u r e f i n a l l y adopted was s u c c e s s i v e e x t r a c -t ion of a l l s a m p l e s as a group with four - 1 h r changes of b o i l i n g d i s t i l l e d water and a i r - d r y i n g , fo l lowed with a l c o h o l - b e n z e n e (1:2) for 24 h r i n a Soxhlet a p p a r a t u s . A s e x a m p l e of e x t r a c t i o n s tudies , four t r e a t m e n t s of five r e p l i c a t e s e a c h were a p p l i e d to the same Douglas f i r l a tewood m e a l ; fo l lowing n i t r a t i o n on the m o i s t u r e - f r e e e x t r a c t e d m e a l , that g i v i n g the h ighes t y i e l d with l e a s t v a r i a t i o n d ic ta ted the c o u r s e of future w o r k . In o r d e r of i n c r e a s i n g y i e l d , the t r e a t m e n t s w e r e found to be e thyl e ther , ethanol , water (46.1 + 1.0%); water , e ther , a l c o h o l (49.3 + 1.3%); a l c o h o l -benzene , water (49.7 + 0.8%); and water , a l c o h o l - b e n z e n e (51.0 +_0.3%). It was not the p u r p o s e of this thes i s to t h o r o u g h l y e x a m i n e the i n t e r a c t i o n of wood e x t r a c t i o n h i s t o r y with n i t r o c e l l u l o s e p r e p a r a t i o n . O b v i o u s l y , s o m e s e r i o u s effects a r e i n v o l v e d . T h e l i t e r a t u r e neg lec t s these e n t i r e l y . C . V a l i d i t y of R e s u l t s T h e a p p l i c a t i o n of s ta t i s t i c s to wood c h e m i s t r y p r o c e d u r e s is p r i m i t i v e o r often neg lec ted , with consequence that the v a l i d i t y of s o m e r e s u l t s i s open to s e r i o u s ques t ion . W i t h this i n m i n d , both s a m p l e s i ze and r e p l i c a t i o n n u m b e r w e r e c a r e f u l l y e x a m i n e d i n the p r e s e n t study. T a b l e 2 shows a t y p i c a l c a l c u l a t i o n for d e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r . T h e p r o c e d u r e was r e p e a t e d s e v e r a l t i m e s d u r i n g deve lopment of methods for the p u r p o s e of eva luat ing p r o g r e s s i n c o n t r o l l i n g e x p e r i m e n t a l e r r o r . T h e objec t ive was to m i n i m i z e the amount of m a t e r i a l needed for a s t a t i s t i c a l l y defens ib le d e t e r m i n a t i o n . T h u s , i t was f i n a l l y found that, to d e t e r m i n e 57 y i e l d r e l i a b l y for a s ingle p o s i t i o n wi th in a wood growth i n c r e m e n t , on ly 3 x 0. 1 g = 0. 3 g of wood m e a l was needed. In addit ion, this s a m p l e s i z e s u p p l i e d suf f ic ient c e l l u l o s e n i t ra te for n i t r o g e n c o r r e c t i o n s and v i s c o s i t y d e t e r m i n a t i o n s . T h e amount of c e l l u l o s e r e c o v e r e d as the n i t ra te was c a l c u l a t e d f r o m the y i e l d c o r r e c t e d for the n i t r o g e n p e r c e n t a g e of the d e r i v a t i v e : M i l e s (91) g ives a convenient equat ion for t h i s : . 100 N P = 3 1 . 13 - N \_2~] w h e r e p = i n c r e a s e i n weight of 100 g of "ce l lu lo se" N = n i t r o g e n , % T h e s y m b o l "p" i s r e a l l y a c o n v e r s i o n fac tor u s e d to reduce weight o f n i t r o c e l l u l o s e to weight of "ce l lu lo se" ( r e g a r d e d h e r e as an e s t imate of <=>C - c e l lu lose ) and i s d e r i v e d f r o m the r e l a t i o n s h i p (rat io) between m o l e -c u l a r weights of c e l l u l o s e t r i n i t r a t e and c e l l u l o s e . A s the f o r m e r is 297 and the la t t er 162 this ra t io i s then 1.833, wh ich c o r r e s p o n d s to c o m p l e t e n i t r a t i o n of c e l l u l o s e (14. 15% N)* U s e of 0. 2 g s a m p l e s gave good r e s u l t s u s i n g three r e p l i c a t e s , but r e q u i r e d twice the amount of m a t e r i a l as 0. 1 g without l a r g e change i n absolute value o r r e l i a b i l i t y . B y u s i n g 0. 05 g, r e p r o d u c i b i l i t y was l o s t . T h e f ina l p r o c e d u r e , a p p l i e d to t h r e e 0. 1 g r e p l i c a t e s for s a m p l e s f r o m four o ther s p e c i e s , gave va lues not un l ike those for the Douglas f i r e a r l y -and la tewood. T h e r e f o r e , i t was conc luded that this n u m b e r wou ld be s u f f i -c ient for a l l wood t i s s u e s . W h e r e the d i f f erence (range) among the three r e p l i -cates was m u c h g r e a t e r than the conf idence i n t e r v a l of 1.2%, or w h e r e the absolute y i e l d a p p e a r e d quest ionable , dupl icate sets of de terminat ions w e r e done and m o d a l va lues w e r e chosen f r o m a l l data r e p r e s e n t i n g a p o s i t i o n . II. N i t r a t i o n P r o c e d u r e A . M i x e d A c i d P r e p a r a t i o n T h e p r o c e d u r e u s e d for p r e p a r i n g the n i t r a t i n g m i x t u r e was that deve loped b y A l e x a n d e r and M i t c h e l l (2) and m o d i f i e d b y T i m e l l (134). A d d i t i o n a l f ea tures w e r e d i s c o v e r e d . A n a l y t i c a l grade , c o l o r l e s s , 90% f u m i n g n i t r i c a c i d (120 m l ) was p o u r e d into a 500 m l , g l a s s - s t o p p e r e d E r l e n m e y e r f l a s k . T h i s was i m m e r s e d i n a D e w a r f lask (140 m m d i a m e t e r ) f i l l e d with ethylene g l y c o l and c o o l e d to about - 1 5 ° C u s i n g a " W h i r l p o o l " t h e r m o e l e c t r i c i m m e r s i o n c o o l e r (Can lab M o d e l 84-640) r e g u l a t e d b y t r a n s f o r m e r . U s e of a l a r g e r d i a m e t e r D e w a r f lask d id not a l low the d e s i r e d t e m p e r a t u r e d e p r e s s i o n , p r e s u m a b l y b e c a u s e of g r e a t e r coolant s u r f a c e a r e a exposed to the a t m o s p h e r e . S ince the a c i d was s l i gh t ly c o l o r e d as r e c e i v e d f r o m the s u p p l i e r , i t was n e c e s s a r y to r e m o v e the n i t r o g e n oxides b y b u b b l i n g t h r o u g h d r y n i t r o g e n . T o do th i s , a two l i t e r r o u n d - b o t t o m e d f lask was f i l l e d t h r e e - f o u r t h s fu l l of a c i d , p l a c e d i n a heat ing mant l e , and heated to 4 0 ° ito 5 0 ° C for on ly 1 to 2 h r (139). D u r i n g this t i m e , and for an h o u r fo l lowing the heat ing p e r i o d , a s t r e a m of n i t r o g e n , p a s s e d c o n s e c u t i v e -l y through cone s u l f u r i c a c i d and c a l c i u m c h l o r i d e was b u b b l e d through a gas d i s p e r s i o n tube into the a c i d . O n b e c o m i n g c o l o r l e s s , the a c i d was a l lowed 59 to c o o l and was s t o r e d i n the o r i g i n a l bott le at 0 ° C . A tota l amount of 72 g of o v e n - d r y , a n a l y t i c a l grade p h o s p h o r u s pentoxide was we ighed into a b e a k e r and then added i n s m a l l i n c r e m e n t s to the a c i d . W i t h each addit ion, the f lask was s w i r l e d v i g o r o u s l y to d i s s ipate the heat of so lut ion and a v o i d r e l e a s e of b r o w n f u m e s . A f t e r each addit ion, the f lask contents w e r e coo l ed to - 1 5 ° C . and the b e a k e r s e a l e d f r o m the a t m o s p h e r e wi th a l u m i n u m f o i l . F o l l o w i n g the l a s t addit ion, the c loudy white m i x t u r e was kept at r o o m t e m p e r a t u r e for 1 to 1 1/2 h r and s w i r l e d f r e q u e n t -l y . A t this stage, the m i x t u r e was c o m p o s e d of two d i s t inc t i m m i s c i b l e p h a s e s , both of w h i c h w e r e c l e a r and c o l o r l e s s . T h i s was r e f r i g e r a t e d at 5 ° C for 4 to 6 h r , r e m o v e d and s w i r l e d v i g o r o u s l y into one m i s c i b l e phase , and r e f r i g e r a t e d for a s econd p e r i o d of 5 to 6 h r . F o l l o w i n g th i s , the m i x t u r e was r e a d y for u s e . O v e r n i g h t s torage of the n i t r a t i o n m i x t u r e i s a l lowed . M a x i m u m u s e f u l s torage t i m e , however , i s one or two days after the p r e p a r a t i o n i s s t a r t e d . B e y o n d this p e r i o d , c r y s t a l s a r e depos i ted on the f lask b o t t o m and the c o m p o s i t i o n of the a c i d changes . O n p r e p a r a t i o n , the so lu t ion contains n i t r i c a c i d , p h o s p h o r i c a c i d , and p h o s p h o r u s pentoxide i n a weight ra t io of 64:26:10. T h i s m i x e d a c i d m u s t be c l e a r and c o l o r l e s s the fo l lowing day, and any m i n o r p a r t i c l e s m a y be r e m o v e d by f i l t r a t i o n o v e r f r i t t e d g l a s s . A l t h o u g h i n i t i a l i m m i s c i b i l i t y has been e n c o u n t e r e d be fore , no r e a s o n has b e e n advanced for this b e h a v i o r (136), n o r i s one g iven for the r e q u i r e d "aging" p e r i o d fo l lowing t r a n s i t i o n into one phase . In the p r e s e n t w o r k it was found that both features are n e c e s s a r y o r the a c i d r e m a i n s or s epara te s as a two-phase s y s t e m d u r i n g the f i r s t stage of n i t r a t i o n . B . N i t r a t i o n T h e p r o c e d u r e for n i t r a t i n g wood m e a l i s that d e s c r i b e d b y T i m e l l (134). A f t e r d r y i n g o v e r p h o s p h o r u s pentoxide under r e d u c e d p r e s s u r e (1 to 2 days) , wood m e a l (0 .10 g) was we ighed into a 50 m l we igh ing bott le and s t o p p e r e d . A t n i t r a t i o n , the bott le was i n v e r t e d , opened and with the m e a l r e m a i n i n g i n the l i d , 6 m l of n i t r a t i n g m i x t u r e at - 1 5 ° C w e r e t r a n s f e r r e d to the bott le u s i n g a c l ean , c a l i b r a t e d 20 m l g l a s s h y p o d e r m i c b a r r e l and p l u n g e r . T h e m e a l was added g r a d u a l l y i n s m a l l por t ions whi le the f la sk contents w e r e s w i r l e d ins tant ly and v i g o r o u s l y on each addi t ion . U p o n the l a s t addi t ion , the bott le was r e - s t o p p e r e d , s w i r l e d to c l e a n the s ides of a d h e r i n g wood m e a l , and set as ide at 18 + 1 ° C . A water bath was kept at the p r o p e r t e m p e r a t u r e b y u s i n g an e l e c t r o t h e r m a l vol tage r e g u l a t o r to c o n t r o l a c o n s t a n t - h e a d r e s e r v o i r fed b y a s t r e a m of c o l d tap w a t e r . T h e t i m e s r e q u i r e d for deve lopment of m a x i m u m n i t r o c e l l u l o s e y i e l d at p r o p e r degree of subst i tut ion with m i n i m u m n i t r o c e l l u l o s e d e p o l y -m e r i z a t i o n v a r i e d between woods of d i f ferent spec i e s , r a n g i n g f r o m 38 to 40 h r for P a c i f i c s i l v e r f i r , w e s t e r n r e d c e d a r , and the s p r u c e s , to 43 to 45 h r for Douglas f i r . T h e s e t i m e s w e r e i n a g r e e m e n t with those d e t e r m i n e d b y Ifju (61) and T i m e l l (130) for s i m i l a r s p e c i e s . W e s t e r n h e m l o c k , 61 t a m a r a c k , jack p ine , and ye l low c e d a r f a i l e d to n i t ra te p r o p e r l y . D u r i n g the r e a c t i o n p e r i o d , f lask contents w e r e s w i r l e d at l ea s t s i x t i m e s at e v e n l y - s p a c e d i n t e r v a l s . T h i s p r o v e d e s s e n t i a l i n o r d e r to m i n i m i z e v a r i a t i o n i n y i e l d and p r o v i d e p r o d u c t s with p r o p e r n i t r o g e n content Qi. e. , 13.8% o r h i g h e r ) . In contras t , for r e a s o n s unknown, continuous m e c h a n i c a l agi tat ion is known to give m e a s u r e a b l e den i t ra t ion and r e d u c t i o n i n i n t r i n s i c v i s c o s i t y after the f i r s t 20 h r of n i t r a t i o n (129, 137). C . C e l l u l o s e N i t r a t e R e c o v e r y P r o d u c t s of wood n i t r a t i o n w e r e r e c o v e r e d a c c o r d i n g to the m e t h o d of T i m e l l (134). A f t e r c o m p l e t i n g n i t r a t i o n for the r e q u i r e d t i m e p e r i o d , the f la sk and contents w e r e c o o l e d to - 1 5 ° C . T h e a c i d s and so luble p r o d u c t s w e r e r e m o v e d b y f i l t r a t i o n through a 30 m l c o a r s e , f r i t t e d - g l a s s c r u c i b l e , suc t ion b e i n g i n t e r r u p t e d b e f o r e a i r en tered the s o l i d r e s i d u e . T h i s was fo l lowed b y i m m e d i a t e addi t ion and r e m o v a l of 40 m l of 50% aq ace t i c a c i d at - 1 5 ° C (104) and 40 m l of i c e d water . T h e c r u c i b l e was r e m o v e d , f i l l e d with sa tura ted aq s o d i u m b i c a r b o n a t e , and left for 5 m i n to s o l u b l i z e some of the n i t r a t e d , o x i d i z e d , and d e g r a d e d l i g n i n . T h e b i c a r b o n a t e was d i s p l a c e d with 30 m l of 10% aq a c e t i c a c i d at 0 ° C and the r e s i d u e was washed with d i s t i l l e d water unt i l washings w e r e n e u t r a l . T h i s was t r a n s f e r r e d with m e t h a n o l to a 50 m l E r l e n m e y e r and shaken m e c h a n i c a l l y for 1 h r to r e m o v e the r e m a i n i n g l i g n i n d e g r a -dat ion p r o d u c t s . Good l i g n i n r e m o v a l i s e s s e n t i a l i n obta in ing a n i t r a t e that i s c o m p l e t e l y a c e t o n e - s o l u b l e (2). T h e n i t r a t e d m e a l was r e t u r n e d to the c r u c i b l e , r i n s e d with m e t h a n o l , and t r a n s f e r r e d to a 250 m l w i d e - m o u t h E r l e n m e y e r conta in ing 150 m l of acetone . T h i s was s t i r r e d at 2, 200 r p m for 5 m i n with a m e c h a n i c a l s t i r r e r . A f t e r u n d i s s o l v e d r e s i d u e s ( p r o b a b l y nat ive x y l a n d in i trates ) s e t t l ed o v e r 12 h r , the c l e a r ye l low supernatant l i q u o r was decanted whi le the s w o l l e n r e s i d u e was c e n t r i f u g e d at 15, 000 r p m for 1 to 1 1/2 h r and w a s h e d once . T h e supernatant so lut ions w e r e c o m b i n e d and p o u r e d into one l i t e r of d i s t i l l e d w a t e r . P r e c i p i t a t e d n i t r o c e l l u l o s e f i b r e s w e r e c o l l e c t e d a r o u n d a spatu la and p r e s s e d into a flat m a s s . T h e r e c o v e r e d p r o d u c t p r o b a b l y conta ined m i n o r amounts of g a l a c t o g l u c o m a n n a n or g l u c o m a n n a n t r i n i t r a t e s o c c l u d e d with the c e l l u l o s e t r i n i t r a t e , although m o s t contaminants a r e r e p o r t e d to r e m a i n i n so lu t ion on addi t ion of the acetone so lut ion to water (134). T h e p r e c i p i t a t e was t r a n s f e r r e d to a 30 m l f r i t t e d - g l a s s c r u c i b l e , w a s h e d with water and m e t h a n o l and, fo l lowing 4 to 5 h r a i r - d r y i n g , the m a t e r i a l was d r i e d under r e d u c e d p r e s s u r e o v e r p h o s p h o r u s pentoxide at r o o m t e m p e r -ature for 24 h r . F o l l o w i n g a n a l y s i s for y i e l d , n i t r o g e n content, and v i s c o s i t y , it was s t o r e d i n the c o l d . N i t r a t i o n is a r e v e r s i b l e p r o c e s s ; b e i n g very r a p i d i n the e s t er f o r m a t i o n stage, but e x t r e m e l y s low i n the d e - e s t e r i f i c a t i o n o r h y d r o l y s i s s tage. H e n c e , u s i n g h igh DS and p r o p e r r e c o v e r y techniques l e s s e n s the chance for n i t r a t e e s t er r e m o v a l (deni trat ion) . H o w e v e r , opportuni t i e s for d e n i t r a t i o n m a y be i n c r e a s e d e n o r m o u s l y b y r a i s i n g t e m p e r a t u r e (91). S ince m a j o r heat effects at any stage of the n i t r a t i o n p r o c e s s a r e those a c c o m p a n y i n g a c i d d i lu t ion (the heat of the n i t r a t i o n i t s e l f b e i n g neg l ig ib le ) , 63 the s u c k i n g of a i r through the r e s i d u e and inef f ic ient or t a r d y drowning cause l o c a l t e m p e r a t u r e i n c r e a s e s w h i c h p r o m o t e a s e r i o u s den i t ra t ing effect (91). O f c o u r s e , this w i l l a d v e r s e l y affect absolute y i e l d and v i s c o s i t y va lues as w e l l as r e p r o d u c a b i l i t y b y i n t r o d u c i n g a l a r g e e x p e r i m e n t a l e r r o r . III. N i t r o g e n D e t e r m i n a t i o n T h e p r e f e r r e d m e t h o d for d e t e r m i n i n g tota l n i t ra te e s ter n i t r o g e n on c e l l u l o s e t r i n i t r a t e i s the s e m i - m i c r o K j e l d a h l d iges t ion (6, 49, 61). G a s -v o l u m e t r i c methods , whi le su i table , a r e e i ther l e s s r e p r o d u c i b l e (37) o r m o r e tedious (56); s p e c t r o p h o t o m e t r y methods m a y y i e l d a c c u r a t e r e s u l t s (29, 79) but r e q u i r e e laborate , s o p h i s t i c a t e d equipment and l a c k the s i m -p l i c i t y of p r o c e d u r e e s s e n t i a l for r a p i d a n a l y s i s . B r i e f l y , the e s ter is d iges ted with c o l d cone s u l f u r i c a c i d i n the p r e s e n c e of a r e a d i l y C - n i t r a t e d , a r o m a t i c c o m p o u n d ( s a l i c y l i c acid) and the n i t r o a r o m a t i c c o m p o u n d thus f o r m e d i s r e d u c e d with s o d i u m t h i o -sulfate to an a m i n e (56). W h i l e the D e v a r d a m o d i f i c a t i o n (56) e m p l o y s d iges t ion i n a lka l ine so lut ion wi th a m e t a l , a m o r e sui table m e t h o d i s the use of a t r a c e of s e l e n i u m with the th iosul fate to ca ta lyze r e d u c t i o n (21). T h e so lut ion m a y then be t r e a t e d with an excess of s o d i u m h y d r o x i d e and the a m m o n i a d i s t i l l e d into b o r i c a c i d and t i t r a t e d d i r e c t l y with s t a n d a r d a c i d . T h i s m e t h o d of M a and Z u a z a g a (82) i s c o m m o n l y u s e d . Its d i sadvantage i s that the b u f f e r i n g ac t ion of the b o r i c a c i d m a k e s the end point l e s s s h a r p than with the b a c k - t i t r a t i o n m e t h o d u s i n g n i c k e l a m m o n i u m sulfate (148). N e s s l e r ' s reagent g ives d i r e c t c o l o r i m e t r i c d e t e r m i n a t i o n of a m m o n i a in the digest . A l t h o u g h m o r e r a p i d than s e m i - m i c r o o r m i c r o - K j e l d a h l , i t i s r e p o r t e d to be not so a c c u r a t e o r dependable (148). T h e a n a l y t i c a l p r o c e d u r e u s e d i n the p r e s e n t study was e s s e n t i a l l y that of M a and Z u a z a g a (82) as m o d i f i e d b y S t e y e r m a r k (119). T a b l e 3 shows a t y p i c a l d e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r for the n i t r o g e n d e t e r m i n a t i o n (n = 2). W h e r e the d i f f erence between the two r e p l i c a t e s was g r e a t e r than the conf idence i n t e r v a l of 0. 16%, a t h i r d d e t e r m i n a t i o n was m a d e and the a v e r a g e of the two c l o s e s t va lues was u s e d . T h e c e l l u l o s e n i t r a t e to be a n a l y s e d for n i t r o g e n was d r i e d i n vacuo o v e r p h o s p h o r u s pentoxide . A 15 to 20 +_ 0. 05 m g p o r t i o n was we ighed on a S p o e r h a s e s e m i - m i c r o a n a l y t i c a l b a l a n c e and t r a n s f e r r e d to a 100 m l A m i n c o d iges t ion - d i s t i l l a t i o n f lask . T h r e e m l of stock so lut ion conta in ing 0. 1 g of reagent grade s a l i c y l i c a c i d and 3. 0 m l of cone s u l f u r i c a c i d w e r e d i s p e n s e d to e a c h f lask b y g lass h y p o d e r m i c b a r r e l and p l u n g e r . T h e contents w e r e shaken m e c h a n i c a l l y for 2 to 3 h r to e n s u r e comple te so lut ion and a r o m a t i c n i t r a t i o n . It was noted that this p r o v i d e s c o n s i d e r a b l e s a v i n g i n t i m e c o m p a r e d with other methods which , unaccountably , spec i fy a l o n g d i s s o l u t i o n p e r i o d without agi tat ion (49, 61). F u r t h e r , i t was found that shak ing gave m o r e r e p r o d u c e a b l e n i t r o g e n va lues than obta ined b y o v e r -night d i s s o l u t i o n without ag i tat ion . A p p r o x i m a t e l y 0. 3 g of reagent grade s o d i u m thiosul fate p e n t a -h y d r a t e was added and, fo l lowing a 15 m i n coo l ing p e r i o d (119), two s e l e n i z e d H e n g a r granu le s w e r e added. T h e f lasks w e r e d iges ted 2 1/2 h r at set t ing 6 on an A m i n c o r o t a r y K j e l d a h l d iges t ion apparatus (3) that h a d b e e n w a r m e d p r e v i o u s l y . F l a s k s w e r e ro ta ted 2 to 3 t i m e s d u r i n g d iges t ion to e n s u r e that s p l a s h e d m a t e r i a l s on the f lask s ides r e f l u x e d into the m a i n contents . O n coo l ing the digest , the f lask s ides w e r e r i n s e d with 10 to 15 m l of d i s t i l l e d water , and the f lask was g r e a s e d and at tached to an A m i n c o s t e a m d i s t i l l a t i o n a s s e m b l y (3). A 125 m l E r l e n m e y e r f la sk conta in ing 10 m l of 4% reagent grade b o r i c a c i d so lut ion and m i x e d i n d i c a t o r was p l a c e d u n d e r the condenser d e l i v e r y tube with the t ip extending beneath the l i q u i d l e v e l . T h e i n d i c a t o r s w e r e b r o m c r e s o l g r e e n (0. 5 g i n 100 m l of ethanol) and m e t h y l r e d (0 .1 g i n 100 m l of ethanol) . T o m a k e a s tock so lut ion for twe lve d e t e r m i n a t i o n s , f ive d r o p s of the f o r m e r and ten of the la t t er w e r e added to 120 m l of the b o r i c a c i d so lut ion . T e n m l of 40% s o d i u m h y d r o x i d e w e r e r u n c a r e f u l l y into the d i s t i l l a t i o n f lask t h r o u g h the en trance tube and the r e s u l t i n g , s t r o n g l y a lka l ine m i x t u r e was s t e a m d i s t i l l e d for 7 m i n and cont inued 2 m i n l o n g e r to wash out the c o n d e n s e r t ip . A n A m i n c o e l e c t r i c s t e a m genera tor was u s e d (3), with the rate of s t e a m g e n e r a t i o n c o n t r o l l e d b y the v a r i a b l e t r a n s f o r m e r . A few m l of d i s t i l l e d water w e r e u s e d to w a s h the s ides of the E r l e n -m e y e r f lask and the b o r i c a c i d so lut ion conta in ing the a m m o n i a was t i t r a t e d to the end point with 0. 02 N h y d r o c h l o r i c a c i d . T h e c o l o r was m a t c h e d to that for an equa l v o l u m e of b o r i c a c i d , both i n d i c a t o r s , and one drop of excess h y d r o c h l o r i c a c i d . T h e t i t r a t i o n a c i d was s t a n d a r d i z e d u s i n g r e c r y s t a l l i z e d b o r a x a c c o r d i n g to the m e t h o d of V o g e l (139); n o r m a l i t y was c h e c k e d i n t r i p l i c a t e be fore e v e r y u s e . B l a n k d e t e r m i n a t i o n s w e r e m a d e i n the absence of a s a m p l e , u s i n g a l l reagents , and the va lue obta ined was s u b t r a c t e d f r o m e x p e r i m e n t a l va lues of a g iven s e r i e s . T h e m e t h o d was s t a n d a r d i z e d against r e c r y s t a l l i z e d reagent p o t a s s i u m n i tra te 66 (n i t rogen content = 13.85%). C a l c u l a t i o n of n i t r o g e n content was as fo l lows: M m l 0. 02 N a c i d ( c o r r e c t e d ) x 14. 008 x 100% [ 4 ] % N i t r o g e n = f —-s a m p l e wt, g ( o v e n - d r y ) , I V . V i s c o s i t y D e t e r m i n a t i o n T h e p r o c e d u r e u s e d for d e t e r m i n i n g i n t r i n s i c v i s c o s i t y was that of Ifju (61) .based on w o r k of D a v i s o n (35). A 3 to 5 + .01 m g s a m p l e was we ighed on a C a h n g r a m e l e c t r i c m i c r o a n a l y t i c a l b a l a n c e and t r a n s f e r r e d to a 15 m l po lye thy lene test tube f itted with a p e r f e c t l y c l o s i n g po lye thy lene c a p . T e n m l of reagent g r a d e acetone w e r e added and the tube was shaken m e c h a n i c a l l y o v e r n i g h t to effect so lut ion . A 5 m l a l iquot was p ipe t t ed to a c l ean , d r y C a n n o n - F e n s k e v i s c o m e t e r (4) a l i gned v e r t i c a l l y and suspended i n a v i s i b i l i t y j a r bath at 25 +_0. 1 ° C . A f t e r wa i t ing 5 m i n for t e m p e r a t u r e e q u i l i b r i u m , the v i s c o m e t e r c a p i l l a r y tube and efflux bulb w e r e f i l l e d b y at taching a r u b b e r bulb to the open a r m and squeez ing gent ly . T h i s technique m i n i m i z e d e v a p o r a t i o n , hence e r r o r s c a u s e d b y d r a w i n g the so lu t ion up the c a p i l l a r y b y d i r e c t suc t ion (4). E f f l u x t i m e was m e a s u r e d to the n e a r e s t 0. 1 sec between the u p p e r and l o w e r etch m a r k s . Be tween d e t e r -m i n a t i o n s , the v i s c o m e t e r was r i n s e d exhaus t ive ly with reagent grade acetone and d r i e d b y p a s s i n g t h r o u g h a i r , then p l a c i n g it i n an oven . P e r i o d i c a l l y , the v i s c o m e t e r was c l e a n e d with aqua r e g i a . S p e c i f i c v i s c o s i t y , , was c a l c u l a t e d f r o m the e x p r e s s i o n t / t - 1, w h e r e t i s efflux t i m e of the so lut ion and t that of p u r e acetone , o o T h i s a s s u m e s that dens i t i es of the solvent and the so lut ion a r e equa l . Ident i f i cat ion of flow t i m e (t) with absolute v i s c o s i t y 1^ i s , s t r i c t l y speaking , i n c o r r e c t and r e s u l t s i n e r r o r i f the so lut ion dens i ty i n c r e a s e s s i g n i f i c a n t l y with c o n c e n t r a t i o n . T h e dens i ty c o r r e c t i o n , wh ich is v e r y s m a l l i n di lute so lut ions of h igh v i s c o s i t y , can be sa fe ly i g n o r e d (121). K i n e t i c e n e r g y l o s s e s o c c u r due to p e r t u r b e d flow at the c a p i l l a r y ends, p a r t i c u l a r l y when an o r g a n i c so lvent with r a p i d efflux t i m e i s u s e d . A c o r r e c t i o n m a y be a p p l i e d (121), but a be t ter so lut ion i s to use a v i s -c o m e t e r with a s m a l l bulb and a l ong c a p i l l a r y of sui table d i a m e t e r . H e r e the k i n e t i c e n e r g y effect would then be r e d u c e d to l e v e l s w h i c h can be d i s r e g a r d e d . . T h e s p e c i f i c v i s c o s i t y va lues so c a l c u l a t e d w e r e c o r r e c t e d for k i n e t i c e n e r g y l o s s e s , a c c o r d i n g to T i m e l l (128); i n the fo l lowing m a n n e r : f F ( t + t ) + 1) ' i .. o o s p s j u s p . <L C 5 J ^ o where : ^ sp = the c o r r e c t e d s p e c i f i c v i s c o s i t y . )^ n sp = o b s e r v e d va lue . and F = a fac tor c a l c u l a t e d for the v i s c o m e t e r f r o m the o e x p r e s s i o n : m do V F ° ~ 8 r f t " T T L £ 6 3 n o o 1 68 w h e r e : m = the k i n e t i c e n e r g y coef f ic ient , (1), i . e . , end effects for the c a p i l l a r y w e r e neg l ec ted . d = dens i ty of acetone (0 .785) . o V = the v o l u m e i n m l of the v i s c o m e t e r bulb (3. 65), the absolute v i s c o s i t y of p u r e acetone (0. 003075 po i se ) . t = the eff lux t i m e of p u r e acetone (162.9 sec) , o L = the length of the c a p i l l a r y (7 .75 c m ) . Subst i tut ing the above va lues into the above e x p r e s s i o n , F for the v i s c o m e t e r o u s e d i n this e x p e r i m e n t was c a l c u l a t e d as 0. 0293548. W h e n the i n t r i n s i c v i s c o s i t y of c e l l u l o s e n i t r a t e i n acetone exceeds a p p r o x i m a t e l y ten (a weight average degree of p o l y m e r i z a t i o n of about 2, 000), the o r i e n t a t i o n of the m o l e c u l e s i n the d i r e c t i o n of flow l o w e r s the apparent i n t r i n s i c v i s c o s i t y . T h e effect i n c r e a s e s with i n c r e a s i n g m o l e c u l a r weight, and the e r r o r i n i n t r i n s i c v i s c o s i t y exceeds 10% for c e l l u l o s e of h ighes t D P (121). T h i s affects s h e a r grad ien t which , for each bulb at a g iven c o n c e n t r a t i o n , i s c a l c u l a t e d f r o m the f o r m u l a of K r o e p l i n (121): G = 8V/3TT r 3 t L 7 ] w h e r e : r = c a p i l l a r y r a d i u s (0 .02125 c m ) i A f t e r c o r r e c t i n g s p e c i f i c v i s c o s i t y va lues for k i n e t i c e n e r g y l o s s , the i n t r i n s i c v i s c o s i t i e s w e r e c a l c u l a t e d b y m e a n s of the S c h u l t z - B l a n s c h k e and H u g g i n s equation, as g iven b y D a v i s o n (35): r - ^ P 0 , U " 1 -~K^7p t 8 1 where : J ^ _ , = the i n t r i n s i c v i s c o s i t y c o r r e s p o n d i n g to the shear , G , at wh ich the m e a s u r e m e n t was m a d e . K = a fac tor taken as 0. 30 a c c o r d i n g to D a v i s o n (35). 69 C = c o n c e n t r a t i o n i n d l / g . T h e i n t r i n s i c v i s c o s i t y |{|]Q> v a r i e s i n a r e g u l a r m a n n e r c o r r e s -pond ing to shear dependence of the v i s c o s i t y (126, 127). O n the other hand, rate of shear depends upon efflux t i m e which , i n t u r n , i s i n f l u e n c e d b y both c o n c e n t r a t i o n and n i t r o c e l l u l o s e D P . In o r d e r to obta in c o m p a r a b l e va lues for the v a r i o u s concentra t ions of d i f ferent D P n i t r a t e s , a l l r e s u l t s w e r e adjusted to the 500 sec v e l o c i t y grad ient b y u s i n g the fo l lowing r e l a t i o n -ship r e p o r t e d b y D a v i s o n (35): l o s L<l 500 = p l ° e • T o V + l o e rf1 G C 9 ] w h e r e : P = the s lope of the s tra ight l ine r e l a t i n g the l o g of i n t r i n s i c v i s c o s i t y to the l og of rate of s h e a r . P m a y be d e t e r m i n e d b y the fo l lowing e x p r e s s i o n : C io 1 d logtf^G d l o g G D a v i s o n (35) d e t e r m i n e d P e x p e r i m e n t a l l y and r e l a t e d P to i n t r i n s i c v i s c o s i t y b y the fo l lowing equat ion: P = 0.0039 v/l] - 0 . 8 x l 0 " 8 frf] C l O ^ 500 500 S ince P i s r e l a t e d to i n t r i n s i c v i s c o s i t y at 500 sec * i n e q u a t i o n t l l l , the va lue obta ined b y subst i tut ing [ J ^ I Q i n this equation can be u s e d to ca l cu la te the f i r s t a p p r o x i m a t i o n of the s lope P . T h i s va lue , when subst i tuted i n equat ion C9 3 , g ives a f i r s t a p p r o x i m a t i o n to |yjl 500* 70 W h e n r e subst i tuted into equation O i l » ^ 1 5 Q Q g ives a b e t t e r e s t imate of P . T h i s b r a c k e t i n g technique can be cont inued u n t i l the r e s u l t i n g \dj 500 C ^ I A N S E S l e s s than 0.001 i n i n t r i n s i c v i s c o s i t y with e a c h s u c c e s s i v e step. T h e l a b o r i o u s c a l c u l a t i o n can be r e p l a c e d b y c o m p u t e r so lut ion ( U . B . C . W o o d S c i e n c e P r o g r a m WS 7040-2) . T h e extent to w h i c h c e l l u l o s e n i t ra te i s subst i tuted g r e a t l y affects its i n t r i n s i c v i s c o s i t y . A n i n c r e a s e i n DS f r o m 2. 3 to 3. 0 (12. 0 to 14. 15% of n i trogen) doubles the i n t r i n s i c v i s c o s i t y . If n i t r o g e n a n a l y s i s shows l e s s than fu l l subst i tut ion, the f o r m u l a of L i n d s l e y and F r a n k ( 8 0 ) i s u s e d to c o n v e r t the i n t r i n s i c v i s c o s i t y to a c o m m o n b a s i s , that i s , to what i t would be w e r e the s a m p l e fu l l y n i t r a t e d : l Q g , n — = l o g f + (14. 15 - X) B c \ z l w h e r e : 1^ ^ = the i n t r i n s i c v i s c o s i t y of the f u l l y n i t r a t e d c e l l u l o s e . the i n t r i n s i c v i s c o s i t y of the p a r t i a l l y n i t r a t e d s a m p l e . f = 1 . 8 3 3 - 0 . 589x, a funct ion w h i c h accounts x for the d i f f erence i n m o l e c u l a r weights between p a r t i a l l y and f u l l y n i t r a t e d c e l l u l o s e . x = the p e r cent n i t r o g e n i n the p a r t i a l l y n i t r a t e d s a m p l e . B = 0 . 114, an e m p i r i c a l constant . S ince a l l v i s c o s i t y m e a s u r e m e n t s i n this study w e r e c a r r i e d out at 2 5 ° C , f u r t h e r adjus tment of the i n t r i n s i c v i s c o s i t y va lues i s n e c e s s a r y . A l l r e s u l t s w e r e c o n v e r t e d into va lues c o r r e s p o n d i n g to those taken at 71 2 0 ° C t e m p e r a t u r e b y m u l t i p l y i n g the i n t r i n s i c v i s c o s i t i e s d e t e r m i n e d b y 1. 04716. T h e fac tor was obta ined f r o m the T r e i b e r and A b r a h a m s o n r e l a t i o n s h i p as r e p o r t e d b y Ifju (61). V . L i g n i n D e t e r m i n a t i o n T h e p r o c e d u r e u s e d h e r e for u l t r a - v i o l e t s p e c t r o p h o t o m e t r i c d e t e r m i n a t i o n of l i g n i n was o r i g i n a t e d b y J o h n s o n et a l . (65). M o i s t u r e -f ree wood m e a l of a c c u r a t e l y d e t e r m i n e d weight (0. 020 g) i s p l a c e d i n a g lass tube hav ing a notched , g r o u n d - g l a s s s topper . T e n m l of 25% reagent grade a c e t y l b r o m i d e i n ace t i c a c i d i s added and the tube i s p l a c e d i n a water bath at 70_+ 1 ° C and s w i r l e d gently at 10 m i n i n t e r v a l s to a s s i s t d i s s o l u t i o n . A f t e r e x a c t l y 30 m i n , the contents are c o o l e d at 13 + 1 ° C for 8 to 10 m i n , then t r a n s f e r r e d to a 200 m l v o l u m e t r i c f lask conta in ing 9 m l of 2 M s o d i u m h y d r o x i d e and 50 m l of ace t i c a c i d . T h e t r a n s f e r i s c o m p l e t e d b y r i n s i n g with 5 to 10 m l of ace t i c a c i d and fo l lowing th i s , 1 m l of 7. 5 M h y d r o x y l a m i n e h y d r o c h l o r i d e i s added to the f lask . E x a c t l y 5 m i n fo l lowing t r a n s f e r , the contents a r e m a d e up to v o l u m e with reagent grade ace t i c a c i d and the m i x t u r e i s c o o l e d u n d e r c o l d water . P e a k a b s o r b a n c e i s then m e a s u r e d at 282 m u , and l i g n i n i s c a l c u l a t e d a c c o r d i n g to the fo l lowing equat ion: _ _ A b s o r b a n c e [| 13 3 L i g n m c A b s o r p t i v i t y x m o i s t u r e - f r e e s a m p l e wt w h e r e a b s o r p t i v i t y is d e t e r m i n e d for each s p e c i e s . S ince this m e t h o d was f i r s t p u b l i s h e d i n 1961, v a r i o u s aspects of the technique have b e e n r e - e x a m i n e d and e r r o r s not i m m e d i a t e i n h e r e n t have b e e n e n c o u n t e r e d . It has been d e m o n s t r a t e d (157) that an i n c r e a s e of 7 m g i n s a m p l e weight l o w e r s l i g n i n d e t e r m i n e d b y 0. 1% and, s i m i l a r l y , i n c r e a s i n g d i lu t ion b y 50 m l o r a b s o r b a n c e b y 0 .4 l o w e r s l i g n i n d e t e r m i n e d b y the s a m e amount . A s t r o n g i n t e r a c t i o n of s a m p l e s i ze with d i lu t ion and a b s o r b a n c e i s also evident . Studies on e l a p s e d t i m e between d i lu t ion and m e a s u r e m e n t have shown that di lute solut ions m a y be s t o r e d i n the c o l d for 24 h r , and s t i l l p r o v i d e stable a b s o r b a n c e s . A l s o noted was the r a p i d n a g i n g f l o f a c e t y l b r o m i d e , such that a b s o r p t i v i t y va lues b e c a m e e r r a t i c o n l y h o u r s after p r e p a r i n g f r e s h l y d i s t i l l e d reagent; this was avo ided , h o w e v e r , b y s e a l i n g f r e s h stock under n i t r o g e n i n i n d i v i d u a l a m p u l e s . W u (156) r e c o g n i z e d and c o r r e c t e d s e v e r a l of these i n c o n s i s t e n c i e s and e s t i m a t e d l i g n i n va lues for S i t k a s p r u c e , Douglas f i r , w e s t e r n h e m l o c k P a c i f i c s i l v e r f i r , and w e s t e r n r e d c e d a r . T h e s e o r i g i n a l data, as w e l l as new data for b l a c k s p r u c e and Douglas f i r a r e u s e d h e r e to e x p l o r e the i m p o r t a n t l i g n i n - c a r b o h y d r a t e r e l a t i o n s h i p s f r o m o b s e r v a t i o n s of t h e i r r e s p e c t i v e p a t t e r n s . 73 E X P E R I M E N T A L R E S U L T S Changes i n s o m e i m p o r t a n t c h e m i c a l p r o p e r t i e s a c r o s s con i f erous growth zones a r e s u m m a r i z e d i n T a b l e 4. E s t i m a t e d l i g n i n and - c e l l u l o s e contents , and n i t r o c e l l u l o s e v i s c o s i t y a r e tabulated for woods f r o m t h r e e g e n e r a and four spec ie s of P i n a c e a e (Si tka s p r u c e , b l a c k s p r u c e , Douglas f i r , and P a c i f i c s i l v e r f ir ) and one spec ies of C u p r e s s a c e a e ( w e s t e r n r e d c e d a r ) . E s t i m a t e d <^ >^  - c e l l u l o s e i s shown as that r e c o v e r e d as n i t r o c e l l u l o s e and c o r r e c t e d for n i t r o g e n content u s i n g the equat ion of M i l e s (91). A v e r a g e s for <^></ - c e l l u l o s e ( T a b l e 4) a r e d e t e r m i n e d on the b a s i s of at l ea s t t h r e e r e p l i c a t e s and, except for two pos i t ions i n Douglas f i r I n c r e m e n t N o . 40, a v e r a g e s for l i g n i n a r e b a s e d on two r e p l i c a t e s . S i tka s p r u c e h a d the h ighes t a v e r a g e y i e l d of cxi - c e l l u l o s e (48. 3%), fo l lowed i n d e c r e a s i n g o r d e r b y both Doug las f i r s a m p l e s (which h a d i d e n t i c a l a v e r a g e y i e l d s of 46.7%), b l a c k s p r u c e (45.2%), P a c i f i c s i l v e r f i r (44.9%), and w e s t e r n r e d c e d a r (44. 0%). W e s t e r n r e d c e d a r had the h ighes t average l i g n i n content (31. 2%), fo l lowed i n t u r n b y b l a c k s p r u c e (29. 5%), Douglas f i r I n c r e m e n t N o . 40 (27.8%), P a c i f i c s i l v e r f i r (27.5%), Doug las f i r I n c r e m e n t s N o . 64 to 66 (26. 7%), and S i t k a s p r u c e (25. 7%). L a r g e v a r i a b i l i t y was encountered among v i s c o s i t y r e p l i c a t e s and v e r y f requent ly the v i s c o s i t y range at one p o s i t i o n o v e r l a p p e d those of contiguous p o s i t i o n s . It was dec ided , t h e r e f o r e , that these data have l i t t l e m e a n i n g other than as a qua l i ta t ive m e a s u r e of s a t i s f a c t o r y de r i v a t i v e f o r m a t i o n . 74 E x a m i n a t i o n of m a t e r i a l f r o m a f r e s h l y - c u t Douglas f i r t r e e ( Increment N o . 40) and b l a c k s p r u c e r e v e a l e d the two r e p r e s e n t a t i v e c > < / - c e l l u l o s e e a r l y w o o d pat terns as shown i n F i g . 1. R e p l i c a t e va lues a r e p lo t ted above each p o s i t i o n e x m a i n e d . A r e c e n t (60) m a t h e m a t i c a l m o d e l d e s c r i b e s e a c h p a t t e r n b y u t i l i z i n g r e l a t i v e p o s i t i o n wi th in the i n c r e -ment , p e r cent latewood, and e s t i m a t e d c<^ - c e l l u l o s e y i e l d . T h e m o d e l , s t a n d a r d e r r o r of e s t imate ( S E ) , and r e g r e s s i o n and c o r r e l a t i o n E coef f ic ients (b and r , r e s p e c t i v e l y ) w e r e c a l c u l a t e d f r o m a c o m p u t e r so lut ion ( U . B . C . W o o d S c i e n c e P r o g r a m WS7040-3 ) . L i n e a r r e g r e s s i o n s and c o r r e l a t i o n coef f ic ients of the - c e l l u l o s e content on p o s i t i o n a r e l i s t e d for a l l i n c r e m e n t s in T a b l e 5. R e s u l t s of a n a l y s i s of v a r i a n c e ( A N O V A ) for - c e l l u l o s e content wi th in growth zones of e a c h spec ies a r e tabulated i n the u s u a l f o r m as T a b l e s 6 t h r o u g h 11. F o r each spec i e s , l e a s t s ign i f i cant ranges between p o s i t i o n m e a n s (Duncan's m u l t i p l e - r a n g e test) a r e p r e s e n t e d c o i n c i d e n t a l l y with A N O V A r e s u l t s i n T a b l e s 6a through 11a. F o r a l l ten i n c r e m e n t s , pa t terns of e s t i m a t e d ax^ - c e l l u l o s e , e s t i m a t e d l i g n i n , and t h e i r c o m b i n e d va lues a r e p lot ted i n F i g . 2. T a b l e 12 l i s t s l i n e a r r e g r e s s i o n s and c o r r e l a t i o n coef f ic ients of e s t i m a t e d oC - c e l l u l o s e on l i g n i n contents for a l l i n c r e m e n t s of each s p e c i e s . F i g u r e 3 d e s c r i b e s the h i g h l y s ign i f i cant l i n e a r c o r r e l a t i o n between these l i g n i n and <=><L - c e l l u l o s e e s t imates for a l l pos i t i ons s tudied wi th in i n c r e m e n t s . 75 F r o m F i g . 2 a l l i n d i v i d u a l and c o m b i n e d l i g n i n and - c e l l u l o s e va lues w e r e p lo t ted for each p o s i t i o n and i n c r e m e n t and a r e p r e s e n t e d as F i g . 4. T h e la t ter shows that the d i s p e r s i o n about the c o m b i n e d data i s s i g n i f i c a n t l y l e s s than that about e i ther of the two i n d i v i d u a l m e a n s . C o r r e l a t i o n coeff ic ients f r o m l i n e a r r e g r e s s i o n s of [/t^ on CX^ - c e l l u l o s e y i e l d for four spec i e s a r e tabulated i n T a b l e 13. A s a m e a n s of showing c h a i n - l e n g t h v a r i a t i o n i n e a r l y w o o d , data c o r r e s p o n d i n g to f i r s t - f o r m e d e a r l y w o o d t i s sues a r e i n c l u d e d or e x c l u d e d f r o m each r e g r e s s i o n . 76 D I S C U S S I O N T h e p r e s e n t study is not c o n c e r n e d with d e s c r i p t i o n of m o l e c u l a r s t r u c t u r e s o r , for that m a t t e r , with deve lopment of p r o c e d u r e s for d e r i v i n g s tatements on u l t i m a t e c h e m i c a l p u r i t y . R a t h e r , its p u r p o s e and attention a r e f o c u s s e d on a f i r s t e s t imate of i m p o r t a n t quantitat ive r e l a t i o n s h i p s of m a j o r wood const i tuents that ex i s t i n t i s s u e s s a m p l e d wi th in con i ferous growth zones . A n s w e r s w e r e sought to such quest ions as where , how m u c h , and how a r e these i n t e r - r e l a t e d . T h i s d i f f ers f r o m the a i m s of b a s i c wood c h e m i s t r y . T h e two approaches f requent ly come together b y i n t e r c h a n g e of m e t h o d s . It i s u n d e r s t o o d that future deve lopments m a y p r o v i d e m e a n s for m a k i n g fine adjustments to the f i r s t a p p r o x i m a t i o n s d e r i v e d i n this study. D i r e c t n i t r a t i o n of wood s e e m e d a l i k e l y a n a l y t i c a l too l for m e a s u r i n g an i n t r a - i n c r e m e n t c a r b o h y d r a t e y i e l d f r a c t i o n . T h i s p r o v e d to be c o r r e c t ; however , l i m i t a t i o n s , as w e l l as advantages a r e attendant with the m e t h o d . F o r e x a m p l e , con i f erous wood n i t ra te s m a y contain s m a l l quantit ies (up to 7%) of mannans , but v e r y l i t t l e (below 1. 5%) x y l a n s (130). It m a y be argued , then, that the d e r i v a t i v e does not m e e t the c l a s s i c def in i t ion as o<f - g lucan . T h a t i s , i t i s not p u r e 1, 4 - $ - D - g l u c o -a n h y d r o p y r a n o s e . T h i s i s r e c o g n i z e d i n the p r e s e n t study, where y i e lds c o r r e c t e d for n i t r o g e n a r e r e g a r d e d as r e a s o n a b l e e s t imates of o / - c e l l u -lo se , such as those p r e p a r e d f r o m convent iona l h o l o c e l l u l o s e s (124). T h e s e e s t i m a t e s , t h e r e f o r e , i n c l u d e the u s u a l p a r t i a l g lucan p r o d u c t s without attempt to r e s o l v e v a r i a t i o n s b y extens ive ana lys i s of const i tuent c a r b o h y d r a t e s . T h e la t ter p r o c e d u r e s , as u s e d b y T i m e l l (130), a lso c a r r y a d i sadvantage i n that ra t io s between m o n o m e r sugars m u s t be a s s u m e d i n o r d e r to m a k e c o r r e c t i o n s . A m a j o r l i m i t a t i o n of the m i c r o - n i t r o c e l l u l o s e m e t h o d is that i t cannot be u n i v e r s a l l y a p p l i e d to a l l woods . T h a t i s , the s u c c e s s of the m e t h o d depends on ab i l i t y to m a n u f a c t u r e a sui table d e r i v a t i v e . E v e n with m a n y t r i a l s and adjustments of p r o c e d u r e , this was not a c c o m p l i s h e d with four spec ie s of the p r e s e n t study: jack pine , t a m a r a c k , w e s t e r n h e m l o c k , and ye l low c e d a r . O t h e r w o r k e r s (18, 129, 137) have h a d s i m i l a r e x p e r i -ence i n c h e m i c a l t r e a t m e n t of s o m e of these woods . A fur ther inherent d isadvantage with n i t r o c e l l u l o s e is that the p r o d u c t cannot be r e d u c e d to c e l l u l o s e without c o l l a p s e of the c e l l u l o s e c h a i n . V i s c o s i t y data w e r e m o s t l y u s e f u l for i n d i c a t i n g p r e s e n c e or absence of extens ive d e g r a d a t i o n as one c r i t e r i o n for judging s u c c e s s f u l n i t r o c e l l u l o s p r e p a r a t i o n . T h e y a l so p r o v i d e d s o m e c o m p a r i s o n s of i n t r a - i n c r e m e n t d i f f erences in c h a i n - l e n g t h . S ince [ffi i s a m o r e sens i t ive m e a s u r e of degradat ion than cs^ - c e l l u l o s e y i e l d b y n i t r a t i o n , the h i g h e r v a r i a b i l i t y n i t r a t i o n p r o c e d u r e . F o r in s tance , the range of - c e l l u l o s e y i e l d v a r i e m i g h t be expected to v a r y even m o r e than th i s . T h i s i n t e r a c t i o n of wood e x t r a c t i o n h i s t o r y with n i t r o c e l l u l o s e p r e p a r a t i o n has been c o m p l e t e l y a s s o c i a t e d with e m p h a s i z e s the need for r e f i n e m e n t of the wood a p p r o x i m a t e l y 5%, depending on e x t r a c t i v e p r e - t r e a t m e n t ; , t h e r e f o r e 78 n e g l e c t e d i n the l i t e r a t u r e ! M e a n s for e s t i m a t i n g l i g n i n with s m a l l amounts of m a t e r i a l s e e m to be be t ter e s t a b l i s h e d s ince the a c e t y l b r o m i d e - a c e t i c a c i d m e t h o d for U V l i g n i n d e t e r m i n a t i o n was f i r s t p u b l i s h e d (65). H o w e v e r , c e r t a i n i n c o n s i s t e n c i e s have been found (157). W u (156) r e c o g n i z e d and c o r r e c t e d s e v e r a l of these i n c o n s i s t e n c i e s , brought the technique to a s t a t i s t i c a l l y defens ib le l e v e l , and fo l lowed b y e s t i m a t i n g i n t r a - i n c r e m e n t l i g n i n pat terns for s e v e r a l s p e c i e s . W u and W i l s o n (157) a l so showed that a v e r a g e l i g n i n va lues obta ined for the woods s tudied c o m p a r e d w e l l with va lues found i n the l i t e r a t u r e . T h e s e data a r e r e p o r t e d as p a r t of T a b l e 4 and p lot ted in F i g . 2. T h e s e l i g n i n va lues p lus new data for b l a c k s p r u c e and Douglas f i r w e r e u s e d to e x p l o r e i n t r a - i n c r e m e n t c e l l u l o s e - l i g n i n r e l a t i o n s h i p s . In s u m m a r y , data d e v e l o p e d and u s e d i n this s tudy are r e g a r d e d as s t a t i s t i c a l l y defens ib le e s t imates of the two m a j o r con i ferous i n t r a -i n c r e m e n t wood c h e m i c a l components for w h i c h no absolute m e a s u r e o r p r o c e d u r e s have yet b e e n advanced . I. R e v i e w of Data A . A l p h a - c e l l u l o s e E s t i m a t e s T h e range of a v e r a g e <=*C - c e l l u l o s e e s t imates found for the five spec i e s r e p o r t e d i n this study (44. 0% to 48.3%) a r e r e c o r d e d i n T a b l e 4. T h e s e agree f a v o r a b l y with those found by T i m e l l (130) who r e p o r t e d a range of - c e l l u l o s e b y n i t r a t i o n f r o m 41. 3% for jack pine and e a s t e r n h e m l o c k ( T s u g a canadens i s ( L . ) C a r r ) up to 46, % to 48% for white s p r u c e as g iven i n T a b l e 1. C l o s e a g r e e m e n t i s a lso noted b y s p e c i e s ; a v e r a g e va lues for both s p r u c e s f a l l i n the s a m e range as white s p r u c e r e p o r t e d b y T i m e l l (130). P a c i f i c s i l v e r f i r a lso c o r r e s p o n d s c l o s e l y to data of T i m e l l (130). T h e s e r e s u l t s a f f i r m the c o n s i s t e n c y of the n i t r o c e l l u l o s e method , w h i c h s e e m s to be independent of s a m p l e s i ze (down to 0. 1 gm) and o p e r a t o r v a r i a b i l i t y . E x c e p t for P o s i t i o n 1 i n w e s t e r n r e d c e d a r , the va lues do not appear to extend the range of whole wood v a l u e s . T h i s p e c u l i a r , s ing le p o s i t i o n was e x a m i n e d . t w i c e i n dupl icate d e t e r m i n a t i o n s which gave the s a m e v a l u e s . Y i e l d of a l p h a - c e l l u l o s e b y n i t r a t i o n c o m p a r e s c l o s e l y to that p r e -p a r e d f r o m convent iona l h o l o c e l l u l o s e de terminat ions on g r o s s wood. T h e f o r m e r m e t h o d i s g e n e r a l l y l o w e r b y 2 to 3%. T h i s agrees with T i m e l l (130), who a s c r i b e d p a r t of this d i f ference as due to the p r e s e n c e of m o r e n o n - g l u c a n m a t e r i a l r e t a i n e d i n convent iona l <cx^  - c e l l u l o s e . T h e d i f f erence i n y i e lds by both methods v a r i e s b y s p e c i e s : In Douglas f i r , for ins tance , the y i e l d range (44. 0% to 49.4%) c o m p a r e s c l o s e l y to that found b y K e n n e d y and J a w o r s k y (68) who r e p o r t e d a range of c h l o r i t e - c e l l u l o s e content of 45% to 51% on whole wood. T h e f o r m e r , however , appears to have m o r e i n h e r e n t v a r i a t i o n than the 46% to 48% range i n c h l o r i t e cx^ - c e l l u l o s e found b y H a l e and C l e r m o n t (53). T h e d i f f erence between both methods of e-*/' - c e l l u l o s e m e a s u r e m e n t , however , appears g r e a t e r for P a c i f i c s i l v e r f i r . T h i s i s at v a r i a n c e with what T i m e l l (130) r e p o r t e d ; p r e v i o u s l y he showed that y i e lds of cxT - c e l l u l o s e f r o m c h l o r i t e h o l o c e l l u l o s e and n i t r a t i o n a r e e s s e n t i a l l y the s a m e v a l u e . W i t h white s p r u c e and e a s t e r n white c e d a r ( T h u j a o c c i d e n t a l i s L . ), T i m e l l (130) found that d i f f erences w e r e evident; these w e r e 2. 5% and 4. 3%, r e s p e c t i v e l y . T h e r e f o r e , for the r e l a t e d spec i e s of th is s tudy (both s p r u c e s and w e s t e r n r e d cedar) i t i s p r o b a b l e that - c e l l u l o s e as e s t i m a t e d b y the n i t r o c e l l u l o s e m e t h o d m a y be low b y a p p r o x i m a t e l y these amounts . B . V i s c o s i t y E s t i m a t e s S ince no attempt was m a d e to d e t e r m i n e c e l l u l o s e p o l y m o l e c u l a r i t y , va lues r e p o r t e d a r e r e g a r d e d as r e p r e s e n t i n g average e s t i m a t e s . It i s r e c o g n i z e d that i n d i v i d u a l n i t r o c e l l u l o s e s p r o b a b l y conta ined v a r i a b l e c h a i n -length d i s t r i b u t i o n s , for in s tance as peaks r e p o r t e d b y T i m e l l (129, 137) for s o m e of the s a m e s p e c i e s . A l t h o u g h n i t r a t i o n y i e lds p r o d u c t s s i m i l a r to those of the o r i g i n a l c e l l u l o s e (49), i t i s r e c o g n i z e d that the h a r s h condit ions undergone b y wood t i s sues d u r i n g n i t r a t i o n cause s o m e c h a i n - l e n g t h d e g r a d a t i o n (134). E x c e p t for Douglas f i r I n c r e m e n t N o . 40, it appears that l i t t l e c h a i n - l e n g t h d e g r a -dat ion o c c u r r e d a c r o s s any of the growth i n c r e m e n t s . A s shown b y b l a c k s p r u c e v i s c o s i t y data, s torage of wood as a b l o c k i n c o l d t h y m o l so lut ion a p p e a r e d to i n v o l v e l e s s degradat ive effects than when wood m e a l was s t o r e d under n i t r o g e n at r o o m t e m p e r a t u r e . T h i s focuses attention aga in on the inf luence of wood p r e t r e a t m e n t . 81 What is p u z z l i n g i s the l o w e r jjjrf f r o m f r e s h l y - c u t Doug las f i r ( Increment N o . 40). T h i s was s ec t ioned and n i t r a t e d i m m e d i a t e l y after s a m p l i n g the t r e e . T h e on ly r e a s o n g iven for its l o w e r v i s c o s i t y i s that p e r h a p s this wood was o v e r - n i t r a t e d , hence o v e r - e x p o s e d to the h y d r o l y t i c effect of c h a i n - s c i s s i o n . W h i l e i s known to d e c r e a s e after e a r l y stages of n i t r a t i o n ( 1 2 9 ) ; p r e v i o u s e x p e r i e n c e ga ined i n th is study and e l s e w h e r e ( 1 2 9 ) ind ica tes that jj^ l does not m a r k e d l y d e c r e a s e unt i l about the t i m e of m a x i m u m n i t r a t i o n . T h e range of n i t r o c e l l u l o s e va lues on s t o r e d Douglas f i r m e a l s c o m p a r e d f a v o r a b l y with that of Ifju (61), who r e p o r t e d a v e r a g e |ff^  of two e a r l y w o o d and la tewood r e p l i c a t e s as 34. 0 and 36. 0 d l / g r e s p e c t i v e l y . It i s unfortunate that i n t r a - i n c r e m e n t \j^J pa t terns cou ld not be e s t a b l i s h e d f r o m the p r e s e n t p r e p a r a t i o n s . B e c a u s e of e x c e s s i v e v a r i a b i l i t y e n c o u n t e r e d a m o n g r e p l i c a t i o n s , the r e l i a b i l i t y of d e t e r m i n i n g an average f r o m these wou ld have l i t t l e m e a n i n g for b e t w e e n - p o s i t i o n c o m p a r i s o n s for , v e r y f requent ly , the range of at one p o s i t i o n o v e r l a p p e d that of cont iguous p o s i t i o n s . In v iew of this l i m i t a t i o n , t h e r e f o r e , i t is felt that these v i s c o s i t y data give i n d i c a t i o n on ly of the range of r e l a t i v e c h a i n - l e n g t h d e g r a d a t i o n a c r o s s the growth i n c r e m e n t s s tud ied . P e r h a p s m o r e attention needs to be g iven to a c c u r a c y of the n i t r o g e n d e t e r m i n a t i o n . B y the f o r m u l a of L i n d s l e y and F r a n k (80), unit changes i n a c c o m p a n y changes i n n i t r o g e n content of a p p r o x i m a t e l y 0. 1%. H e n c e , it i s sugges ted that the m e t h o d of n i t r o g e n d e t e r m i n a t i o n be adapted to the use of 0. I N s t a n d a r d a c i d and t h r e e r e p l i c a t i o n s . 82 C . L i g n i n E s t i m a t e s E s t i m a t e d a v e r a g e l i g n i n content of b l a c k s p r u c e (29.5%) agrees c l o s e l y with the spec ie s a v e r a g e of 28% (22). T h a t for Douglas f i r I n c r e m e n t N o . 40 (27. 8%) i s wi th in 1% of that r e p o r t e d b y W u (156) for h i s Douglas f i r ; however , both a r e w e l l be low the spec i e s a v e r a g e of 31. 5% (22). T h e s e data a r e r e p o r t e d as p a r t of T a b l e 4 and p lo t ted as F i g . 2. A s both Douglas f i r t r e e s c a m e f r o m the l o w e r m a i n l a n d of B . C . , i t m a y be that Douglas f i r o r i g i n a t i n g f r o m this a r e a , i s c h a r a c t e r i s t i c a l l y l o w e r i n l i g n i n . II. I n t r a - i n c r e m e n t A l p h a - c e l l u l o s e E s t i m a t e s and t h e i r S i g n i f i c a n c e A . T w o R e p r e s e n t a t i v e pat terns Y i e l d of <=>{ - c e l l u l o s e s f r o m Douglas f i r I n c r e m e n t N o . 64 gave a r a t h e r definite p a t t e r n ( F i g . 2), as d id both adjacent growth i n c r e m e n t s , suggest ing that s u c h a p a t t e r n i s a r e g u l a r feature wi th in a g iven con i f erous s t e m . E x a m i n a t i o n of m a t e r i a l f r o m a s econd Douglas f i r s t e m showed the s a m e r e s u l t . E x a m i n a t i o n of four other woods showed that a s e c o n d p a t t e r n m i g h t o c c u r ( F i g . 2). T h e two - c e l l u l o s e y i e l d pat terns a r e d e s c r i b e d as fo l lows: 1. A l p h a - c e l l u l o s e y i e l d d r o p p e d s l i gh t ly f r o m P o s i t i o n 1 (or ear lywood) to 2, then r o s e s h a r p l y to a m a x i m u m e i ther at P o s i t i o n 5 o r 6 (latewood) as r e p r e s e n t e d b y Douglas f i r . 2. Y i e l d of - c e l l u l o s e i n c r e a s e d s h a r p l y f r o m P o s i t i o n 1 to 5, whereupon i t e i ther peaked or d r o p p e d off at P o s i t i o n 6; 83 this was c h a r a c t e r i s t i c for both s p r u c e s e x a m i n e d and w e s t e r n r e d c e d a r . 3. P a c i f i c s i l v e r f i r v a r i e d a c c o r d i n g to i n c r e m e n t , fo l lowing e i ther of the above two p a t t e r n s . F r o m r e c e n t work b y Ifju ( 6 l V H o m o k y (59) and W o r r a l l (154) on i n t r a - i n c r e m e n t s p e c i f i c g r a v i t y p r o f i l e s , i t s e e m s a p p r o p r i a t e to c o n s i d e r e a r l y w o o d as i n c l u d i n g P o s i t i o n s 1 to 3; t r a n s i t i o n wood, P o s i t i o n 4; and la t ewood as P o s i t i o n s 5 and 6, when i n c r e m e n t s a r e d i v i d e d into s ix equal p a r t s . T h e two g e n e r a l pat terns of cxT - c e l l u l o s e depos i t ion a r e p r e s e n t e d i n F i g . 1. Douglas f i r r e p r e s e n t s the f i r s t type of pa t t ern , showing m i n i m u m y i e l d at c o n s i d e r a b l e c e l l u l a r depth wi th in the e a r l y w o o d ; this p a t t e r n also ho lds for s i x of the ten i n c r e m e n t s r e p o r t e d ( F i g . 2). M a x i m u m y i e l d m a y be a s s o c i a t e d e i ther with cont inuat ion or c o n c l u s i o n of la tewood growth . B l a c k s p r u c e r e p r e s e n t s the s e c o n d type of pa t t ern , showing m i n i m u m y i e l d at the i n i t i a t i o n of e a r l y w o o d . A s with Douglas f i r , m a x i m u m y i e l d was a s s o c i a t e d e i ther wi th cont inuat ion o r c o n c l u s i o n of la tewood growth . F i g . 1 a lso shows that no d i f f erence i n c h a i n - l e n g t h i s apparent throughout e i ther i n c r e m e n t . E a c h p a t t e r n i s m o s t a c c u r a t e l y d e s c r i b e d b y a r e c e n t m a t h e m a t i c a l m o d e l ( l o g a r i t h m i c equation) r e p o r t e d b y H o m o k y et_aL_(60), b a s e d on r e l a t i v e p o s i t i o n , p e r cent latewood, and e s t i m a t e d cx^ - c e l l u l o s e y i e l d . F o r b l a c k s p r u c e , I n c r e m e n t N o . 40 S E and r a r e 0 .40 and 0 .95 , r e s p e c t i v e l y ; i n the s a m e o r d e r , these are 0. 60 and 0 .96 for Douglas f i r I n c r e m e n t N o . 40. F o r c o m p a r i s o n p u r p o s e s , l i n e a r r e g r e s s i o n s for both spec i e s a r e l i s t e d i n T a b l e 5; these do not fit the b l a c k s p r u c e and Douglas f i r data as •well as does the m o d e l . T r a n s f o r m a t i o n s have been u s e d with s u c c e s s to i m p r o v e the fit i n cases w h e r e n o n - l i n e a r i t y has o c c u r r e d with r e l a t i o n s h i p s between wood p r o p e r t i e s . W i l s o n and Ifju (150) have d e s c r i b e d t e n s i l e s trength b e h a v i o r s a c r o s s con i f erous i n c r e m e n t s , b y u s i n g an arc tangent funct ion . T h e a p p l i c a t i o n h e r e of the p a r t i c u l a r t r a n s f o r m a t i o n : £n Y = a + b x + b x + b x (60 ) I s its f i r s t use to d e s c r i b e n o n -l i n e a r b e h a v i o r of a wood c h e m i c a l p r o p e r t y a c r o s s a con i f erous growth i n c r e m e n t . B v C h e m i c a l E v i d e n c e for T w o E a r l y w o o d T y p e s T h e ex i s tence of m i n i m u m cx'- c e l l u l o s e y i e l d deep wi th in the e a r l y -wood ( P o s i t i o n 2) i s new c h e m i c a l ev idence suggest ing o c c u r r e n c e of a m a j o r p h y s i o l o g i c a l change with p r o g r e s s of s e a s o n a l growth; this i s cons i s tent with, and t h e r e b y r e - a f f i r m s the dual e a r l y w o o d hypothes i s of W u and W i l s o n (157). T o r e i t e r a t e , this hypothes i s states that e a r l y w o o d a r i s i n g f r o m " o v e r w i n t e r e d " x y l a r y m o t h e r c e l l s r e t a i n s a c h e m i c a l p r e - d i s p o s i t i o n towards la tewood of the p r e c e d i n g s eason . It i m p l i e s , t h e r e f o r e , a d i f f erence i n c h e m i c a l c o m p o s i t i o n f r o m that of ce l l s f o r m e d b y new c a m b i a l d i v i s i o n s wi th in the p r e s e n t g r o w i n g season . M o r p h o l o g i c a l data on f ibre lengths i n Douglas f i r c a r r y the s a m e sugges t ion (16, 17). T h e hypothes i s r e la t e s 85 to ev idence p r e s e n t e d b y B a n n a n ( 1 0 ) o n e a s t e r n white c e d a r g r o w n i n southern O n t a r i o . B a n n a n (10) found that, on r e s u m p t i o n of c a m b i a l ac t iv i ty , the f i r s t s i te of c e l l d i v i s i o n is i n the o ldes t x y l e m m o t h e r ce l l s contiguous to the a l r e a d y - d i f f e r e n t i a t e d x y l e m ; f u r t h e r m o r e , the grea t m a j o r i t y of these c e l l s , and not the s p e c i f i c l a y e r ( s ) of c a m b i a l i n i t i a l s , are m o s t ac t ive d u r i n g the f i r s t month(s) of r a d i a l growth . H e n c e , B a n n a n (12) o b s e r v e d that a c o n s i d e r a b l e p o r t i o n of e a r l y w o o d m a y be f o r m e d b y r e - d i v i s i o n of (overwintered) x y l e m m o t h e r c e l l s . T h e p o r t i o n m a y i n c l u d e anywhere between 2 to 24 (average of 8) s u c h " o v e r w i n t e r e d " c e l l s (11). W h e r e m a n y such ce l l s o c c u r , this f i r s t - f o r m e d e a r l y w o o d i s s a m p l e d as P o s i t i o n 1 a n d / o r 2 wi th in a s ing le growth i n c r e m e n t . Such a condi t ion m a y have a r i s e n i n Douglas f i r and p o s s i b l y not i n other woods e x a m i n e d although P a c i f i c s i l v e r f i r fo l lowed e i ther pa t t ern , as s tated p r e v i o u s l y . It i s not known whether the d i f f erence i n pat terns r e s u l t s f r o m i n h e r e n t spec i e s d i f f erences or i s a r e s u l t of c l i m a t i c d i f f e r e n c e s . A l p h a - c e l l u l o s e y i e lds at P o s i t i o n 1 c o u l d r e l a t e to the c o m b i n a t i o n of s a m p l i n g p r o c e d u r e and p e r i o d i c i t y of c a m b i a l r e a c t i v a t i o n . W h i l e the c e s s a t i o n t i m e of c a m b i a l d i v i s i o n v a r i e s w i d e l y with al t i tude, la t i tude , c l i m a t e , and site (12), so a l so can this be s a i d for t i m e of c a m b i a l r e a c t i v a t i o n . E v e n where these f a c t o r s a r e s i m i l a r wi th in a s m a l l f o r e s t a r e a , r e a c t i v a t i o n t i m e v a r i e s with spec i e s and i n d i v i d u a l s wi th in s p e c i e s . A t H a n e y , B . C . , W a l t e r s and Soos (140) found that w e s t e r n r e d c e d a r and Douglas f i r c o m m e n c e d shoot growth a c t i v i t y b y the m i d d l e of A p r i l , two weeks b e f o r e that for w e s t e r n h e m l o c k and w e s t e r n white p i n e . A t C o r v a l l i s , O r e g o n , G r i l l o s 86 and S m i t h (50) c l a i m that the c a m b i u m of Douglas f i r r e s u m e s a c t i v i t y d u r i n g the m i d d l e of M a r c h ; the f i r s t d i v i s i o n s o c c u r i n the m o t h e r ce l l s n e a r e s t the m a t u r e x y l e m . W h i l e these o b s e r v a t i o n s o n l y show the effect of lat i tude on shoot growth and c a m b i a l r e a c t i v a t i o n i n Douglas f i r , one cannot deny the in f luence on other s p e c i e s . F o r example , both s p r u c e s u s e d i n the p r e s e n t study c a m e f r o m m o r e n o r t h e r l y la t i tudes ; the S i tka s p r u c e f r o m T e r r a c e , B . C . and b l a c k s p r u c e , f r o m n o r t h e r n Q u e b e c . It cou ld be expec ted that the c a m b i a l zones for both r e s u m e d a c t i v i t y at l a t e r dates than t r e e s f r o m H a n e y , B . C . , wh ich m a y re la te to f r e q u e n c y of x y l a r y m o t h e r c e l l d i v i s i o n s . B e s i d e s d e t e r m i n i n g l i g n i n b y the wood d iges t ion m e t h o d of J o h n s o n et a l . (65), another m e t h o d d e v i s e d b y Chow (28) was a p p l i e d to d e t e r m i n -at ion of l i g n i n wi th in Douglas f i r I n c r e m e n t N o . 40. T h i s p r o v i d e s d i r e c t m e a s u r e m e n t f r o m I n f r a - R e d (IR) s p e c t r o s c o p i c a b s o r p t i o n u s i n g thin ( 2 0 ^ ) tangent ia l wood sec t ions . B o t h l i g n i n methods c o r r e l a t e h igh ly ; the IR m e t h o d a l so r e v e a l s peak l i g n i n content at P o s i t i o n 2, w h i c h r e a f f i r m s b y other m e a n s the ex i s tence of two e a r l y w o o d t y p e s . Chow (28) has, a lso d e r i v e d an e x p r e s s i o n for r e l a t i n g c a r b o x y l / c a r b o n y l ra t io on th in wood t i s s u e s . W i t h i n the e a r l y -wood of Douglas f i r , P a c i f i c s i l v e r f i r , and w e s t e r n r e d c e d a r , where i n c r e m e n t s have b e e n e x a m i n e d , this ra t io peaks at a p p r o x i m a t e l y the same r e l a t i v e p o s i t i o n as shown for l i g n i n d e t e r m i n e d b y h i s m e t h o d . T h e b e h a v i o r fur ther suggests p r e s e n c e of d i f ferent e a r l y w o o d types at the c h e m i c a l funct iona l group l e v e l . 87 C . A l p h a - c e l l u l o s e P a t t e r n s and E a r l y w o o d - L a t e w o o d V a r i a t i o n s F i g . 2 shows e s t i m a t e d o<d - c e l l u l o s e pat terns for a l l ten i n c r e -ments r e p o r t e d . V e r i f i c a t i o n of definite pat terns for each spec i e s was a c h i e v e d b y two s t a t i s t i c a l t e s t s . A n a l y s i s of v a r i a n c e ( A N O V A ) showed c o n -c l u s i v e l y that h i g h l y s ign i f i cant d i f f erences ex i s t ed a m o n g m o s t of the pos i t ions ( T a b l e s 6 to 11). T o d e t e r m i n e s ign i f i cant d i f f erences between p o s i t i o n s , Duncan's m u l t i p l e - r a n g e test was u s e d ( T a b l e s 6a to 11a). In c o m p a r i s o n to the F test, Duncan ' s t es t accounts for the n u m b e r of p o s i t i o n m e a n s c o m p a r e d . In w e s t e r n r e d c e d a r , the f r e s h l y - c u t Douglas f i r , and both s p r u c e s (those s p e c i m e n s w h e r e i n just one i n c r e m e n t was studied), the la tewood was s i g n i f i c a n t l y h i g h e r than e a r l y w o o d i n s>< - c e l l u l o s e y i e l d s . A l t h o u g h this was not e n t i r e l y t r u e with S i t k a s p r u c e l a t ewood ( y i e l d for P o s i t i o n 6 was not s t a t i s t i c a l l y d i f ferent f r o m that for P o s i t i o n s 2 and 3), P o s i t i o n 4 had s i m i l a r y i e l d to that of P o s i t i o n 5, and both of these w e r e s i g n i f i c a n t l y h igher than e a r l y w o o d . W i t h i n w e s t e r n r e d c e d a r e a r l y w o o d , pos i t i ons d i f f e r e d s i g n i f i c a n t l y f r o m e a c h other , whereas none d i f f e r e d wi th in the t r a n s i t i o n -wood- la tewood; this a l so h e l d for the f r e s h l y - c u t Douglas f i r with the except ion that P o s i t i o n 5 was s i g n i f i c a n t l y h i g h e r than the r e m a i n i n g t r a n s i -t i onwood- la t ewood . W i t h i n b l a c k s p r u c e , P o s i t i o n 1 was s i gn i f i can t ly l o w e r than the r e m a i n d e r of e a r l y w o o d , w h e r e a s P o s i t i o n 5 was s i gn i f i can t ly h igher than t r a n s i t i o n w o o d - l a t e w o o d . A l t h o u g h i n a few ins tances y i e l d values f e l l outs ide the d e s i r e d conf idence i n t e r v a l of 1. 0%, this h a d no effect on s i g n i f i -cance of the e a r l y w o o d - l a t e w o o d d i f f e r e n c e s . F o r these spec i e s l i n e a r r e -g r e s s i o n s of o £ - c e l l u l o s e e s t imates on r e l a t i v e p o s i t i o n wi th in growth zones 88 a r e r e p o r t e d i n T a b l e 5. A l l a r e h i g h l y s ign i f i cant . F o r s t o r e d m e a l s f r o m Douglas f i r and P a c i f i c s i l v e r f i r (where in t h r e e adjacent i n c r e m e n t s w e r e studied); A N O V A showed that, as with the s ingle i n c r e m e n t s , h i g h l y s ign i f i cant d i f f erences ex i s t ed a m o n g m o s t p o s i t i o n s . T h i s was t r u e a l so between growth i n c r e m e n t s ( T a b l e s 10 and 11). F o r both spec i e s , l a t ewood y i e lds w e r e s i g n i f i c a n t l y h i g h e r than those of e a r l y w o o d . F o r P a c i f i c s i l v e r f i r , the y i e l d p a t t e r n was the s a m e for a l l t h r e e growth i n c r e m e n t s (as e v i d e n c e d b y negat ive i n t e r a c t i o n ) ; wi th in the e a r l y w o o d , P o s i t i o n 3 was s i g n i f i c a n t l y h i g h e r and i n t r a n s i t i o n w o o d , P o s i t i o n 4 was l i k e w i s e l o w e r ( T a b l e 11a). O n l y one of the t h r e e growth i n c r e m e n t s was s i g n i f i c a n t l y d i f ferent i n a v e r a g e y i e l d . In Douglas f i r , A N O V A r e v e a l e d a h i g h l y s ign i f i cant i n t e r a c t i o n between pos i t i ons and growth i n c r e m e n t s wi th m o s t i n t e r a c t i o n c a u s e d b y v a r i a t i o n at P o s i t i o n s 1 and 2 which , i n t u r n , affected the shape of y i e l d c u r v e s for each r i n g . H e n c e , whi le the g e n e r a l p a t t e r n of y i e l d ho lds for these t h r e e r i n g s , i ts shape i s not constant throughout the s ix p o s i t i o n s i n e v e r y r i n g . B y Duncan ' s test ( T a b l e 10a), P o s i t i o n 3 was s i g n i f i c a n t l y h i g h e r i n y i e l d wi th in e a r l y w o o d whi le P o s i t i o n s 4 and 6 w e r e s i g n i f i c a n t l y d i f ferent f r o m e a c h other , but not f r o m P o s i t i o n 5. I n c r e m e n t s N o . 64 and 66 w e r e s i g n i f i c a n t l y d i f ferent f r o m each o ther , but not f r o m I n c r e m e n t N o . 65. F o r these s a m e m a t e r i a l s , l i n e a r r e g r e s s i o n s of - c e l l u l o s e content on r e l a t i v e p o s i t i o n wi th in growth zones w e r e c o m p u t e d and found to be h i g h l y s ign i f i cant . F o r Douglas f i r and P a c i f i c s i l v e r f i r , c o r r e l a t i o n 89 coef f ic ients w e r e . 86 and . 83 r e s p e c t i v e l y ( T a b l e 5). W h i l e r e g r e s s i o n equations showed that although i n i t i a l c e l l u l o s e y ie lds of Douglas f i r w e r e h i g h e r b y 2%, it i s i n t e r e s t i n g to note the m a r k e d s i m i l a r i t y between r e g r e s s i o n coef f ic ients ( .75 and .76) i n T a b l e 5. T h i s suggests that, for the i n c r e m e n t s s tudied , y i e lds for both spec i e s i n c r e a s e d constant ly and at n e a r l y i d e n t i c a l ra tes d u r i n g t h e i r r e s p e c t i v e growth p e r i o d s . P e r h a p s c e l l u l o s e depos i t ion a c r o s s annual i n c r e m e n t s i s r e g u l a t e d b y a m e c h a n i s m c o m m o n to m o r e than one and p o s s i b l y s e v e r a l s p e c i e s . In v iew of s ign i f i cant c o r r e l a t i o n coef f ic ients , both equations wou ld be u s e f u l for e s t i m a t i n g ^ j ^ / - c e l l u l o s e contents throughout m a t u r e growth i n c r e m e n t s for these s p e c i e s . R e s u l t s f r o m A N O V A and Duncan's m u l t i p l e - r a n g e tests for a l l i n c r e m e n t s r e - a f f i r m the ex i s tence of h i g h e r - c e l l u l o s e o r g lucan content i n la tewood as found b y p r e v i o u s w o r k e r s (53, 55, 76, 89, 102). E a r l i e r r e s u l t s are g iven i n T a b l e 1. A l l , however , s a m p l e d just two points w i th in a growth i n c r e m e n t and a n a l y z e d wood m a t e r i a l b y methods known to have l i m i t a t i o n s , s u c h as c e l l u l o s e p r e p a r e d b y the C r o s s and B e v a n p r o -c e d u r e (33), h o l o c e l l u l o s e b y s o d i u m c h l o r i t e (153), and c e l l u l o s e b y c h r o m a -t o g r a p h y of wood h y d r o l y z a t e s (76, 89). E x c e p t i n g the a n o m a l y i n w e s t e r n r e d c e d a r , the magni tude of e a r l y w o o d - l a t e w o o d d i f f erences for the ten i n c r e m e n t s r e p o r t e d h e r e appears to r e f l e c t the inf luence of t r a n s i t i o n type . Douglas f i r , a spec ie s h a v i n g c h a r a c t e r i s t i c a l l y abrupt t r a n s i t i o n , shows an average d i f f erence of 4 to 5%; both s p r u c e s , on the other hand, a r e c h a r a c t e r i s t i c a l l y woods of g r a d u a l t r a n s i t i o n and show d i f f erences of 90 o n l y Z to 3%. H a l e and C l e r m o n t (53) d e t e r m i n e d c h l o r i t e h o l o c e l l u l o s e on r e d p ine and Douglas f i r e a r l y - and la tewood and found an 8 to 9% d i f f e r e n t i a l . It i s felt that this m a y r e p r e s e n t r a t h e r e c c e n t r i c b e h a v i o r . A l t h o u g h they m e a s u r e d C r o s s and B e v a n c e l l u l o s e i n Douglas f i r , R i t t e r and F l e c k (10Z) showed an e a r l y w o o d - l a t e w o o d d i f f erence of 3-4% which s eems to be i n be t ter a g r e e m e n t with l i t e r a t u r e values, and r e s u l t s r e p o r t e d h e r e . S ince the o n l y p r e v i o u s w o r k showing i n t r a - i n c r e m e n t c h l o r i t e h o l o -c e l l u l o s e and c a r b o h y d r a t e pat terns at m o r e than two pos i t i ons wi th in an i n c r e m e n t was done b y Ifju (61) on Douglas f i r wood, d i s c u s s i o n and c o m p a r i -sons i n th is s ec t i on a r e r e s t r i c t e d to this s ing le s p e c i e s . Ifju's r e s u l t s have b e e n s u m m a r i z e d e a r l i e r (151) whi le those f r o m the p r e s e n t study a r e g iven i n F i g . Z . B o t h sets of data show h i g h e r c a r b o h y d r a t e content i n latewood; howe ve r , s i m i l a r i t y ends h e r e . A p a r t f r o m the 30% d i f f erence i n absolute c a r b o h y d r a t e y i e l d s , what contras t s m o s t i n the c o m p a r i s o n i s the shape of the c u r v e s and the l o c a t i o n of p r o f i l e p e a k s . Ifju 1 s h o l o c e l l u l o s e pat terns fo l low the p a r a b o l i c c u r v e for a l l t h r e e i n c r e m e n t s e x a m i n e d , with the l o w e r of the two c u r v e ends b e i n g at P o s i t i o n 1 and the apex o c c u r r i n g at P o s i t i o n 4, w h i c h r e l a t e s exac t ly to i n i t i a t i o n of la tewood. C o m p a r e d to pat terns of o<l - c e l l u l o s e e s t i m a t e d i n this study, ne i ther Ifju's h o l o c e l l u l o s e n o r g lucan and m a n n a n contents i n d i c a t e d m i n i m u m or m a x i m u m y i e l d at P o s i t i o n Z . T h e second obvious d i f f erence i s the peak ing of h o l o c e l l u l o s e and g lucan p lus m a n n a n contents at the e a r l y w o o d - l a t e w o o d t r a n s i t i o n , whi le t h e o ^ - c e l l u l o s e y i e l d peaks deep wi th in the la tewood o r , l e s s c o m m o n l y , at P o s i t i o n 6.. F r o m Ifju's work , the ga lac tan content fo l lowed m o s t c l o s e l y 9 1 the e s t a b l i s h e d t r e n d for r_>/ - c e l l u l o s e i n this study, whi le the x y l a n content d id the r e v e r s e , showing an a v e r a g e d r o p of 3% f r o m e a r l y - to la tewood. A l t h o u g h pat terns of h o l o c e l l u l o s e and e s t i m a t e d o<^ - c e l l u l o s e content i n Douglas f i r do not agree , addi t ional data f r o m Ifju's w o r k (151) and i n f o r m a t i o n about the acetone s o l u b i l i t y of n o n - g l u c a n n i t ra te s (130) might e x p l a i n s o m e of the d i s c r e p a n c y . T i m e l l (130) found n i t r o c e l l u l o s e of s ix c o n i f e r o u s woods to have an a v e r a g e p u r i t y of 94%. O f the two m a j o r n o n - g l u c a n p o l y s a c c h a r i d e s w h i c h m a y b e r e c o v e r e d with the n i t r o c e l l u l o s e , x y l a n d in i t ra te i s a c e t o n e - i n s o l u b l e (130, 134). It i s p r o b a b l y not i n c l u d e d as s u c h i n the - c e l l u l o s e y i e l d . A s the content of x y l a n i n e a r l y w o o d i s l o w e r b y 2 to 4%, this wou ld p a r t l y exp la in the l o w e r - c e l l u l o s e y i e l d found i n the e a r l y w o o d . T h e r e i s no obvious r e a s o n for the d i f f erence i n l o c a t i o n of p e a k s . T i m e l l (130) has d e m o n s t r a t e d that 4 to 7% g l u c o m a n n a n i s o c c l u d e d i n the n i t r o c e l l u l o s e . If, d u r i n g n i t r a t i o n , p r o p o r t i o n a t e l y m o r e of this s h o r t - c h a i n m a t e r i a l i s s o l u b l i z e d o r los t i n the r e g i o n of its grea tes t o c c u r r e n c e , this wou ld tend to give a r a t h e r u n i f o r m , low c o n t r i b u t i o n of g l u c o m a n n a n throughout the i n c r e m e n t . T h i s l o s s , when c o u p l e d with that of the a c e t o n e - i n s o l u b l e x y l a n d in i t ra te , c o u l d account for the m a j o r d i f f erence between the c u r v e s and peak pos i t ions for h o l o c e l l u l o s e and e s t i m a t e d <=><^  - c e l l u l o s e . R e s i d u e s of x y l o s e and m a n n o s e w e r e not m e a s u r e d i n the p r e s e n t study. 92 In s u m m a r y , c>C - c e l l u l o s e pat terns w e r e e s t a b l i s h e d a c r o s s growth zones f r o m s e v e r a l con i f erous woods . T h e s e pat terns suggest r e l a t i o n s h i p of the l o n g - c h a i n c a r b o h y d r a t e f r a c t i o n to s e a s o n a l deve lopment wi th in c o n i f e r o u s growth zones . C o m p a r i n g r e s u l t s of this s tudy to the l i t e r a t u r e shows good a g r e e m e n t to d e t e r m i n a t i o n s of o £ - c e l l u l o s e e s t i m a t e d b y n i t r o c e l l u l o s e p r e p a r a t i o n . T h e m e t h o d appeals as a m e a n s for e x a m i n i n g minute amounts of m a t e r i a l . T h e use of t h r e e r e p l i c a t e s p e r p o s i t i o n is s t a t i s t i c a l l y de fens ib le . III. R e l a t i o n s h i p between C e l l u l o s e - L i g n i n P a t t e r n s A . E v i d e n c e for C o m p l e m e n t a r y C h a r a c t e r A d i s t inc t nove l ty of the new m e t h o d r e p o r t e d h e r e i n is that a l l data a r i s e at a l e v e l a l l owing c o m p a r i s o n to other c h e m i c a l and p h y s i c a l pa t terns deve loped at the s a m e l e v e l . Notable r e l a t i o n s h i p s were found when l i g n i n and - c e l l u l o s e pat terns w e r e c o m p a r e d for the s a m e pos i t i ons wi th in i n c r e m e n t s ( F i g . 2). T h o u g h d i f f erences for both components between growth zones and spec ie s a r e evident , the p a t t e r n of one i s o b v i o u s l y the c o m p l e m e n t of the o ther . T h i s shows even at the points of changing s lope and for e x t r e m e pos i t i ons within any i n c r e m e n t . T h e i n t e r d e p e n d e n c y i s w e l l e x e m p l i f i e d for P a c i f i c s i l v e r f i r and Douglas f ir , , w h e r e r i n g - t o - r i n g p o s i t i o n a l d i f f erences m o d i f y the l i g n i n p a t t e r n . T h e o< - c e l l u l o s e c o m p l e m e n t of these i s a l m o s t quant i ta t ive ly p e r f e c t . W h e r e no change appears i n the s lope of one component , as with both s p r u c e s for ins tance , so a lso is t h e r e no c o r r e s p o n d i n g change i n the s lope of i t s c o m p l e m e n t . In both s p r u c e s , l i g n i n contents d e c r e a s e s t e a d i l y f r o m P o s i t i o n s 1 to 4 or 5 and, c o n v e r s e l y , o ^ . - c e l l u l o s e y i e lds i n c r e a s e i n the s a m e magni tude t h r o u g h these p o s i t i o n s . W i t h the sole except ion of P o s i t i o n 1 i n w e s t e r n r e d c e d a r , pa t t erns for both components a r e cont inuous ly c o m p l e m e n t a r y throughout the 60 pos i t i ons wi th in the 10 i n c r e m e n t s e x a m i n e d . T h i s adds new d i m e n s i o n for u n d e r s t a n d i n g the c o m p l e x i n t e r - r e l a t i o n s h i p s of the two m a j o r con i f erous wood component s . T h e c o m p l e m e n t a r y i n t e r - d e p e n d e n c y of l i g n i n and cx^ - c e l l u l o s e was c o m p a r e d b y r e g r e s s i o n a n a l y s i s of the c o m b i n e d data (60 p o s i t i o n s ) . In s tudying c e l l d i f f erent ia t ion , i t i s known that l i g n i f i c a t i o n can be f i r s t noted fo l lowing s e c o n d a r y w a l l f o r m a t i o n (143), hence , l i g n i n content was r e g a r d e d as b e i n g dependent on <=>C - c e l l u l o s e content. In F i g . 3 the r e l a t i o n s h i p of this c o m p l e m e n t i s shown as a h i g h l y s ign i f i cant l i n e a r c o r r e l a t i o n (r = - 0 . 785) between the two e s t i m a t e s . B y v i r t u e of this s t r o n g r e l a t i o n s h i p with c o m b i n e d data f r o m n u m e r o u s b o t a n i c a l s o u r c e s , the hypothes i s r e c e i v e s s t r o n g suppor t . F o r the ten c o n i f e r o u s i n c r e m e n t s c o m b i n e d t h e r e i n , the o d - c e l l u l o s e e s t imate was r e l a t e d to l i g n i n b y the equat ion Y = 63. 08 - 0. 773X, w h e r e : Y = l i g n i n and X = © < - c e l l u l o s e e s t i m a t e . T h e c o r r e l a t i o n coef f ic ient c o m p a r e s v e r y f a v o r a b l y wi th that of -0 . 764 as r e p o r t e d b y B y r d et a l . (26)ifor whole wood of l o b l o l l y p i n e . H i g h l y s ign i f i cant l i n e a r c o r r e l a t i o n s w e r e found a lso for eight of the ten i n c r e m e n t s when these w e r e a n a l y z e d s e p a r a t e l y . R e s u l t s of i n d i v i d u a l ana lyses a r e p r e s e n t e d i n T a b l e 12. E x c e p t for the one a n o m a l y i n w e s t e r n r e d c e d a r , the " c o m p l e m e n t " hypothes i s s e e m s to h o l d r e g a r d -94 l e s s of s p e c i e s or i n c r e m e n t . H a d i t been p o s s i b l e to t rea t l i g n i n and <=»<d - c e l l u l o s e r e p l i c a t e s as m a t c h e d o b s e r v a t i o n s , a l l r e g r e s s i o n s l i s t e d i n T a b l e 12 w o u l d have b e e n h i g h l y s igni f icant s ince , as a consequence , degrees of f r e e d o m i n the a n a l y s i s wou ld have been i n c r e a s e d t w o - f o l d . B . E v i d e n c e for M u t u a l l y E x c l u s i v e R e l a t i o n s h i p Be tween C e l l u l o s e and and L i g n i n F u r t h e r ev idence of l i g n i f i c a t i o n as the c o m p l e m e n t of - c e l l u l o s e d i s t r i b u t i o n is p r e s e n t e d i n F i g . 4. A l l m e a n cx^ - c e l l u l o s e e s t imates and l i g n i n va lues w e r e c o m b i n e d and plot ted for e a c h p o s i t i o n with the i n t e n -t i o n of c o m p a r i n g i n t e r - s p e c i e s v a r i a t i o n s . In F i g . 4 a r e shown the m e a n (x) and absolute range of one s t a n d a r d dev iat ion (s) about a v e r a g e s for a l l e s t imates of c><^  - c e l l u l o s e , l i g n i n , and the s u m of both . T h e data t r e a t e d this way p r o v i d e two o b s e r v a t i o n s of note . F i r s t , the s u m of the component e s t imates c l u s t e r s about the c e n t r a l va lue of 72 to 74%. Secondly , d i s p e r s i o n about the c o m b i n e d va lues i s s i gn i f i can t ly l e s s than that about e i ther of the two i n d i v i d u a l m e a n s e x a m i n e d s e p a r a t e l y . T h e s e i m p o r t a n t o b s e r v a t i o n s suggest that for the i n c r e m e n t s s tudied , a l l spec i e s h a d a c o m m o n c r i t i c a l l e v e l that r e p r e s e n t s the s u m of a unique c o m b i n a t i o n of c e r t a i n c e l l w a l l components upon w h i c h the u l t i m a t e s t r u c t u r a l na ture of the c e l l w a l l depends, r e g a r d l e s s of s eason of f o r m a t i o n . T h i s d e m o n s t r a t e s that some c lo se p h y s i o l o g i c a l c o n t r o l exists o v e r these c h e m i c a l components , as i n d i c a t e d b y the s i g n i f i c a n t l y l o w e r d i s p e r s i o n about the c o m b i n e d e s t i m a t e s . W h y this p h e n o m e n a o c c u r s i s not patent ly obvious; however , it does give s t r o n g i n d i c a t i o n of the c lose , f ine ly b a l a n c e d i n t e r - r e l a t i o n s h i p e x i s t i n g b e t w e e n , ^ - c e l l u l o s e and l i g n i n . C l e a r l y , a p r e - d e t e r m i n e d quanti ty of s o m e p r e c u r s o r (e. g. , 72 to 74% i n eventual weight) i s p r o d u c e d in m e t a b o l i c pathways , and b y c o m p l e x b i o -synthet ic sequences , this i s d i r e c t e d for i n c o r p o r a t i o n as e i ther l i g n i n or long c h a i n g lucan e n d - p r o d u c t s (but n e v e r both) s u c h that the s u m for both r e s u l t s i n a s i m i l a r va lue , r e g a r d l e s s of i n d i v i d u a l t r e e or spec ie s d i f f e r e n c e s . T h i s ind icates that con i f erous t r e e p h y s i o l o g y i s o r i e n t e d m o r e towards the f i n i s h e d b i o s y n t h e t i c p r o d u c t r a t h e r than t o w a r d s m a j o r i n d i v i d u a l components i n v o l v e d i n s u c h s y n t h e s i s . T h e constant 26 to 28% of other m a t e r i a l m u s t be h e m i c e l l u l o s e s , wh ich s e e m l e s s w e l l r e l a t e d quant i ta t ive ly to the b a s i c g l u c a n than i s l i g n i n . T h i s amount of h e m i c e l l u l o s e i s n e v e r r e c o v e r e d f r o m m e m b e r s of the C o n i f e r a l e s , w h i c h r e q u i r e d e l i g n i f i c a t i o n b e f o r e h e m i c e l l u l o s e s can be e x t r a c t e d . A s seen i n F i g . 4, va lues for w e s t e r n r e d c e d a r a r e o b v i o u s l y h igh , b e i n g d i s p l a c e d 2 to 3% above the x. T h i s i s the on ly m e m b e r e x a m i n e d that showed s u c h b e h a v i o u r throughout the i n c r e m e n t ; it m a y have a s p e c i f i c p r e - d i s p o s i t i o n towards type of l i g n i n t r e a t m e n t . F o r this spec i e s , l i g n i n d e t e r m i n a t i o n b y u l t r a - v i o l e t s p e c t r o s c o p y has tended to be h i g h i n the o r d e r of 10%. M a c L e a n and M u r a k a m i (85) have found s y r i n g y l as w e l l as g u i a c y l groups i n c e d a r l i g n a n s . T h i s o r other u n d e s c r i b e d p h e n o m e n a m a y contr ibute to h i g h e r a b s o r b a n c e r e a d i n g s and, hence , cause a r t i f i c i a l l y h igh U V l i g n i n v a l u e s . 96 F r o m the c o m p l e m e n t a r y c e l l u l o s e - l i g n i n pat terns ( F i g . 2), t h e i r h i g h l y s ign i f i cant negat ive l i n e a r c o r r e l a t i o n ( F i g . 3) and tendency to c l u s t e r about a c e n t r a l va lue when c o m b i n e d ( F i g . 4), i t i s evident that w h e r e an e x t r a amount of - c e l l u l o s e i s p r e s e n t , this i s a c c o m p a n i e d b y d e f i c i e n c y i n l i g n i n . T h i s is the f i r s t quanti tat ive ev idence for such r e l a t i o n s h i p wi th in c o n i f e r o u s growth zones . T h e s e r e s u l t s support p r e v i o u s ev idence (31, 40, 44, 58, 92, 144) c o n f i r m i n g r a t h e r c l e a r l y that c e l l u l o s e and l i g n i n depos i t ion is m u t u a l l y e x c l u s i v e . T h e r e s u l t s a lso a f f i r m F r e u d e n b e r g ' s (40) c l a s s i c ana logy of c e l l wa l l s as r e - i n f o r c e d c o n c r e t e , w h e r e b y the c r y s t a l l i n e c e l l u l o s e (which is c u s t o m a r i l y r e g a r d e d as c x l - c e l lu lose ) acts as r e - i n f o r c i n g r o d s s u r r o u n d e d , but not d i s p l a c e d , b y n o n - c e l l u l o s i c c e l l w a l l components w h i c h act as cement . C . B i o l o g i c a l In terpre ta t ions T h e m u t u a l l y e x c l u s i v e b e h a v i o r of - c e l l u l o s e and l i g n i n r e f l e c t s a b a s i c d i f f erence i n c h e m i s t r y of the i r r e g u l a r wood known as c o m p r e s s i o n wood, w h e r e i n it has been noted (142) that l i g n i n is a lways h igh and c e l l u l o s e content low. T h e r e i s , however , a fundamenta l d i f f erence i n that r e g u l a r wood exhibi ts an i n t e r c h a n g e a b l e b a l a n c e whi le c o m p r e s s i o n wood changes exhib i t e x c e s s i v e l i g n i n . N e v e r t h e l e s s , this does not r u l e out the ac t ion of a m e c h a n i s m c o m m o n , i n p a r t , to the c h e m i s t r y of both . H o w it opera tes i s a m a t t e r of c o n j e c t u r e . It i s known that h i g h e r aixin contents a c c o m p a n y e a r l y w o o d and c o m p r e s s i o n wood f o r m a t i o n , although, with the la t ter , f a c t o r s other than auxin a r e known to be o p e r a t i v e at c o m p r e s s i o n wood s i tes (74, 142, 145). B o t h wood types a r e r e l a t i v e l y h igh i n l i g n i n content (142, 156). W u and W i l s o n (157) have pos tu la ted that wi th in c o m p r e s s i o n wood, e a r l y w o o d l i g n i n s eems to be constant and la tewood l i g n i n i n c r e a s e s , g iv ing a whole wood effect of h i g h e r l i g n i n for c o m p r e s s i o n wood. T h e r e m a y be , then, s o m e c o r r e l a t i o n between these facts s u c h that auxins in f luence f o r m a t i o n of l e s s o<£ - c e l l u l o s e and m o r e l i g n i n . If this w e r e c o r r e c t , then the l o w e r l i g n i n content of r e g u l a r la tewood r e s u l t s f r o m a l o w e r auxin supply . A s auxin supp ly and t r a n s l o c a t i o n d e c r e a s e wi th r e d u c t i o n i n a p i c a l a c t i v i t y which , i n t u r n , s ign i f i e s la tewood i n i t i a t i o n (74, 145); this a p p r o a c h s e e m s p l a u s i b l e . If s u c h is the case , one w o u l d conc lude a lso that the m e c h a n i s m c o n t r o l l i n g c e l l u l o s e depos i t ion r e s p o n d s i n v e r s e l y to auxin supp ly o r c o n -c e n t r a t i o n . A c t u a l l y , s ince c e l l u l o s e depos i t ion p r e c e d e s l i g n i f i c a t i o n , i t s e e m s l i k e l y that such a m e c h a n i s m would be r e l a t e d m o r e d i r e c t l y to c e l l u l o s e r a t h e r than to l i g n i n . It m i g h t be m o r e c o r r e c t , then, to r e g a r d l i g n i f i c a t i o n as showing i n d i r e c t r a t h e r than d i r e c t r e s p o n s e to auxin inf luence on c h e m i c a l cons t i tut ion a c r o s s the growth zone. O t h e r a p p r o a c h e s have b e e n m a d e as to the cause of l i g n i n and c a r b o h y d r a t e v a r i a t i o n s wi th in the con i f erous growth zone; these w e r e r e v i e w e d r e c e n t l y b y W u and W i l s o n (157). R i t t e r (100) p r e s e n t e d ev idence that the m i d d l e l a m e l l a conta ined 7 5% of the l i g n i n i n wood; a y e a r l a t e r , R i t t e r and F l e c k (102) u s e d this ev idence when they p r o p o s e d that, s ince the m i d d l e l a m e l l a const i tuted a g r e a t e r p r o p o r t i o n of e a r l y w o o d than latewood, the f o r m e r , t h e r e f o r e , h a d a h igh l i g n i n content. In r e a l i t y , 75% of the m i d d l e l a m e l l a i s l i g n i n (9), but 75% of the l i g n i n is not i n the m i d d l e l a m e l l a (15). T h e la t t er contains at m o s t 40% of the to ta l l i g n i n i n wood (15). F o r this r e a s o n , the m i d d l e l a m e l l a t h e o r y a d v a n c e d b y R i t t e r and F l e c k (102) i s suspec t . A c c o r d i n g to W u and W i l s o n (157), P h i l l i p s sugges ted that s o l a r i l l u m i n a t i o n on l e a f s u r f a c e s c o n t r o l s l i g n i f i c a t i o n i n t r o p i c a l and t e m p e r a t e p o r o u s woods . Consequent ly , he showed the f o r m e r to have h i g h e r l i g n i f i -cat ion; h o w e v e r , even i f a p p l i e d to con i f erous woods, such a hypothes i s s e e m s to c o n t r a d i c t the m a j o r o b s e r v a t i o n i n that h i g h e r la tewood l i g n i f i -ca t ion would be ant i c ipated . L a r s o n (76) r e p o r t e d that d e c r e a s i n g l i g n i f i c a t i o n and i n c r e a s i n g g lucose y i e l d a c r o s s a growth zone a r e r e l a t e d not on ly to i n c r e a s i n g c e l l w a l l t h i c k n e s s , but to the aging of the c a m b i u m c o m b i n e d with the d e c l i n i n g inf luence of an u p w a r d r e c e d i n g c r o w n . T h i s l e d h i m to p r o p o s e that changes i n c e l l w a l l c o m p o s i t i o n r e l a t e d to age can be t y p i f i e d b y the e a r l y -wood, w h e r e b y at any age, i ts t r a n s i t i o n to la tewood i s s u p e r i m p o s e d on the e x i s t i n g e a r l y w o o d m a t r i x to r e p r e s e n t a change of a d i f ferent qual i ta t ive na ture (j.. e., i n c r e a s i n g c e l l w a l l t h i c k n e s s ) . P r e v i o u s l y , H a l e and C l e r m o n t (53) i n d i c a t e d that h i g h e r h o l o c e l l u l o s e and c x C - c e l l u l o s e contents i n la tewood a r e a s s o c i a t e d with t h i c k e r S l a y e r s wi th in la tewood p r o s e n c h y m a c e l l w a l l s . T h i s a p p e a r s analogous to L a r s o n ' s e a r l y w o o d m a t r i x a p p r o a c h , i f a p p l i e d at a g iven age. A l t h o u g h c e l l u l o s e and l i g n i n have a c o m m o n o r i g i n as p h o t o s y n -thates , the sequence of bio synthet ic pathways through w h i c h p r e c u r s o r s m o v e has not b e e n c o m p l e t e l y e s t a b l i s h e d . M u c h u s e f u l i n f o r m a t i o n , however , i s a v a i l a b l e . Jones (66) has shown that the f o r m a t i o n of l i g n i n p r e c u r s o r s r e q u i r e s the s a m e unit as that u s e d for synthes i s of hexose s u g a r s , n a m e l y , 3 -D_-phosphog lyceron ic a c i d . P r e c u r s o r s of both components a p p a r e n t l y b r a n c h off at th is point to f o r m i n c r e a s i n g l y d i f f e r i n g enti t ies (30, 66, 73 107, 118) i n spite of the fact that both m a y undergo s i m i l a r t r a n s f o r m a t i o n s m a n y t i m e s . A p p a r e n t l y , some of these p r e c u r s o r s m a y c o m b i n e i n the c a m b i a l zone t o w a r d s the end of the i r b i o s y n t h e t i c sequence . W o r k i n g with N o r w a y s p r u c e , F r e u d e n b e r g (42) ,showed that, i m m e d i a t e l y p r i o r to l i g n i -f i ca t ion , the g r e a t e r p e r c e n t a g e of c o n i f e r y l a l c o h o l i s p r e s e n t i n the c a m b i u m as the g l u c o s i d e c o n i f e r i n . F u r t h e r m o r e , c o n i f e r y l a l c o h o l i s the m a j o r l i g n i n p r e c u r s o r (41, 42). F r e u d e n b e r g (42) goes on to s a y that when the g l u c o s i d e s pass out f r o m the c a m b i u m to i m m a t u r e ce l l s u n d e r -the ag lycones a r e i n t u r n a t tacked b y an abundant dehydrogenase and c o n v e r t e d into l i g n i n . What happens to the g lucose on h y d r o l y s i s i s not stated b y F r e u d e n b e r g , but it i s a l m o s t c e r t a i n l y c o n v e r t e d to c e l l u l o s e . F r o m a d i s c u s s i o n with F r e u d e n b e r g , N e i s h (93) b e l i e v e s that i f c o n i f e r y l a l c o h o l i s o v e r p r o d u c e d i n the s p r u c e c a m b i u m it i s s t a b i l i z e d as a g l u c o -s ide b y r e a c t i o n with U D P - g l u c o s e . T h i s g lucos ide then undergoes the going l i g n i f i c a t i o n , they a r e h y d r o l y z e d to ag lycones b y 100 changes i n d i c a t e d b y F r e u d e n b e r g . H o w e v e r , w h e r e l i g n i f i c a t i o n is r a p i d , N e i s h (93) i m p l i e s that a l l the c o n i f e r y l a l c o h o l f o r m e d i s c o n v e r t e d to l i g n i n . H e does not m e n t i o n f o r m a t i o n of a g l y c o s i d e as an i n t e r m e d i a t e step. H e n c e , it m i g h t be deduced that where l i g n i f i c a t i o n i s r a p i d , the ra t io of l i g n i n to c a r b o h y d r a t e depos i t ion favors the l i g n i n . T h i s might w e l l h o l d for e a r l y w o o d , w h e r e r e l a t i v e l y h i g h e r l i g n i n (156) and auxin contents have b e e n found i n con i ferous woods (74, 142, 145). W h e r e l i g n i f i c a t i o n i s not so r a p i d , c o n i f e r y l a l c o h o l w i l l f i r s t be s t a b i l i z e d as a g l u c o s i d e , w h i c h then m o v e s out f r o m the c a m b i u m . H e r e the ra t io of components does not favor l i g n i n as m u c h as b e f o r e . T h i s m i g h t apply to la tewood, s ince growth p r o c e s s e s and c e l l m a t u r a t i o n (e. g. i n c l u d i n g l ign i f i ca t ion) a r e not n e a r l y so r a p i d as i n e a r l y w o o d , and l i g n i n content is s i g n i f i c a n t l y l o w e r (156). I V . R e l a t i o n s h i p of A l p h a - c e l l u l o s e P a t t e r n s to P h y s i c a l P r o p e r t i e s A . S trength P a r a m e t e r s It was p r e v i o u s l y noted that, for the ten i n c r e m e n t s r e p o r t e d , the magni tude of e a r l y w o o d - l a t e w o o d d i f f erences i n o < - c e l l u l o s e y i e l d appears to r e f l e c t the inf luence of type of e a r l y w o o d - l a t e w o o d t r a n s i t i o n . W h i l e Douglas f i r - c e l l u l o s e y i e l d fo l lowed a s i g m o i d c u r v e ( F i g s . 1 and 2), both s p r u c e s and P a c i f i c s i l v e r f i r d i s p l a y e d m o r e g r a d u a l i n c r e a s e i n cX^ - c e l l u l o s e y i e l d a c r o s s the i n c r e m e n t . T h i s effect i n these same s p e c i e s has b e e n noted for s o m e i n t r a - i n c r e m e n t p h y s i c a l p r o p e r t i e s b y Ifju et a l . (62) and H o m o k y et a l . (60). 101 W i t h r e g a r d to p h y s i c a l p r o p e r t i e s , t e n s i l e and r a d i a l c o m p r e s s i v e s trengths of Douglas f i r a r e c o r r e l a t e d with s p e c i f i c g r a v i t y to a h i g h l y s ign i f i cant degree"(59, 60, 61, 62). T h a t i s , with a n e a r l y t h r e e - f o l d i n c r e a s e i n s p e c i f i c g r a v i t y , s t rength i n c r e a s e s p r o p o r t i o n a t e l y . F r o m the n e w l y - e s t a b l i s h e d p a t t e r n of cr>£ - c e l l u l o s e d i s t r i b u t i o n for the same spec i e s (though no d i r e c t ev idence i s es tabl i shed) , i t is u n l i k e l y that the a p p r o -x i m a t e l y 5% y i e l d d i f f e r e n t i a l between e a r l y - and la tewood of any of the above spec i e s w o u l d account for the 300% strength i n c r e a s e with the same t i s s u e . H e n c e , i t would appear that s u c h s trength p r o p e r t i e s i n r e g u l a r wood of Douglas f i r depend to a l a r g e degree upon v a r i a t i o n s r e f l e c t i n g degree of c e l l w a l l p a c k i n g , a l i gnment and a s s o c i a t i v e p r o p e r t i e s between c e l l w a l l components r a t h e r than on those r e f l e c t i n g amount of l o n g - c h a i n c e l l u l o s i c m a t e r i a l . T h e m a t e r i a l d i f f erence h e r e is the r e m a i n i n g c e l l w a l l c o m -ponents , these b e i n g p r e d o m i n a n t l y l i g n i n and h e m i c e l l u l o s e ; thus, i n in f luenc ing b a s i c s trength p r o p e r t i e s , the i m p o r t a n c e of these components is e m p h a s i z e d . T h e r o l e of l i g n i n (40) has a l r e a d y been l i k e n e d to that of c o n c r e t e r e - i n f o r c i n g s u r r o u n d i n g s tee l r o d s ( ce l lu lose ) , whi le that of h e m i c e l l u l o s e i s , p e r h a p s , not quite as c l e a r l y e s t a b l i s h e d . B . P h y s i c a l E v i d e n c e for T w o E a r l y w o o d T y p e s W i t h i n Douglas f i r growth zones W i l s o n and Ifju (150) d i s c e r n e d anomalous b e h a v i o u r of two p h y s i c a l p r o p e r t i e s i n e a r l y w o o d ; whi le s p e c i f i c g r a v i t y (G) r e m a i n e d r e l a t i v e l y constant, u l t imate t ens i l e s trength ( U T S ) i n c r e a s e d p r o g r e s s i v e l y a c r o s s this zone with as m u c h as a t h r e e -fo ld change. T h i s p r o n o u n c e d n o n - l i n e a r i t y was also evident (but not 1 d i s c u s s e d ) i n r e s u l t s of K l o o t (71), who showed that s p e c i m e n s of r a t h e r u n i f o r m l y low weight (ear lywood) d i s p l a y e d a l a r g e v a r i a t i o n i n u l t i m a t e t ens i l e l o a d . In v iew of both s tudies , W i l s o n and Ifju (150) sugges ted that whi le at h igh s p e c i f i c g r a v i t y , s t rength depends m o r e on amount of wood substance than on its c o m p o s i t i o n , the r e v e r s e m a y be t rue at low l e v e l s of G . T h a t i s to say, e a r l y w o o d s trength i s m o r e affected b y qual i ta t ive r a t h e r than quantitat ive d i f f erences i n wood subs tance . A c c o r d ing to Ifju et_aL_(62), this has a p p a r e n t l y been i m p l i e d b y H i l l . It has been d e m o n s t r a t e d h e r e that l i g n i n and - c e l l u l o s e e s t imate pa t t erns re la t e d i r e c t l y to, and p o s i t i v e l y r e - a f f i r m , the dual e a r l y w o o d hypothes i s of W u and W i l s o n (157). S ince the anomalous e a r l y -wood p h y s i c a l b e h a v i o r noted above re f l ec t s v a r i a t i o n wi th in e a r l y w o o d , it too m u s t r e l a t e to the hypothes i s . T h e r e b y , r e s u l t s f r o m K l o o t (71) and W i l s o n and Ifju (150) b e c o m e the f i r s t ev idence showing v a r i a t i o n i n e a r l y -wood p h y s i c a l p r o p e r t i e s as r e f l e c t i n g the p r e s e n c e of two e a r l y w o o d types r e l a t e s to a c o r r e s p o n d i n g change i n c e l l wa l l s and, i f F r e u d e n b e r g ' s (40) ana logy i s v a l i d , then c e l l u l o s e m u s t change i n s o m e b a s i c c h a r a c t e r -i s t i c a c r o s s the s a m e zone. T h a t for s o m e spec i e s this i s a quantitat ive If, w i th in the e a r l y w o o d zone, the i n c r e a s e i n t ens i l e s t rength change has a l r e a d y been shown f r o m pat terns of - c e l l u l o s e content. Q u a l i t a t i v e ev idence m a y b e i n f e r r e d f r o m the r e g r e s s i o n of n i t r o -c e l l u l o s e on oC - c e l l u l o s e y i e l d . F o r s ing le i n c r e m e n t s of four s p e c i e s , n i t r o c e l l u l o s e l / f l for P o s i t i o n 1 a p p e a r e d h i g h e r on the a v e r a g 103 than that for the r e m a i n i n g e a r l y w o o d . L i n e a r r e g r e s s i o n s w e r e d e t e r m i n e d on data p lo t ted f r o m a l l s i x pos i t i ons and on these same data w h e r e i n P o s i t i o n 1 was o m i t t e d ( T a b l e 13). W h e n the data f r o m P o s i t i o n 1 w e r e r e m o v e d , a be t ter fit o c c u r r e d ; when these w e r e i n c l u d e d , t h e i r in f luence was s u c h that the s lope even changed s ign i n one in s tance . T h i s suggests f u r t h e r ev idence of two e a r l y w o o d types on the b a s i s of a v e r a g e c h a i n -length . 104 C O N C L U S I O N S A m e t h o d has been d e v i s e d for a c c u r a t e m i c r o - c e l l u l o s e d e t e r -m i n a t i o n . A l p h a - c e l l u l o s e y i e l d m a y be quant i ta t ive ly e s t i m a t e d f r o m m i n u t e s a m p l e s of wood m e a l as the c o r r e c t e d c e l l u l o s e n i t ra te y i e l d . Important v a r i a b l e s w e r e s tudied and i t was shown that t h r e e - 0 . 1 g ( o v e n - d r y ) wood s a m p l e s p r o v i d e a s t a t i s t i c a l l y defens ib le d e t e r m i n a t i o n . I n t r i n s i c v i s c o s i t i e s of these m i c r o - c e l l u l o s e s w e r e u s e d to ind ica te p r e s e n c e or absence of extens ive degradat ion as a m e a n s of q u a l i t a t i v e l y d e c i d i n g s u c c e s s f u l n i t r o c e l l u l o s e p r e p a r a t i o n . A m a j o r l i m i t a t i o n of the new method? h o w e v e r , i s that i t cannot be a p p l i e d to a l l woods . F o r the f i r s t t i m e , a s e r i e s of ten d i s t inc t - c e l l u l o s e pat terns have b e e n e s t a b l i s h e d wi th in con i f erous growth i n c r e m e n t s of w i d e l y d i f ferent b o t a n i c a l o r i g i n (5 genera) . A l l s u c h pat terns r e v e a l e d la tewood to be s i g n i f i c a n t l y h i g h e r (2 to 3%) i n - c e l l u l o s e than e a r l y w o o d . S ix of these p r o v i d e new c h e m i c a l ev idence p e r t a i n i n g to a p h y s i o l o g i c a l l y s ign i f i cant phenomenon , this b e i n g the p r e s e n c e of two types of e a r l y w o o d . T h e r e i n , m i n i m u m e s t i m a t e d - c e l l u l o s e y i e l d o c c u r r e d at c o n s i d e r a b l e c e l l u l a r depth. T h e r e m a i n i n g four i n c r e m e n t s s e e m e d di f ferent , i n that they d i d not conta in the a n o m a l y . E s t i m a t e d Q>^  - c e l l u l o s e content v a r i e d with s p e c i e s . S i t k a s p r u c e h a d the h ighes t a v e r a g e y i e l d , 48. 3% (46. 5 to 50. 1%), fo l lowed b y 105 Douglas f i r , 46. 7% (43. 4 to 49. 8%), b l a c k s p r u c e 45. 2% (43. 1 to 47. 0%), P a c i f i c s i l v e r f i r , 44. 9% (41. 8 to 47. 5%), and w e s t e r n r e d c e d a r , 44. 6% (40. 2 to 46. 0%). Magni tude of e a r l y w o o d - l a t e w o o d d i f f erences i n c x i f - c e l l u l o s e y i e l d a p p e a r e d to r e f l e c t type of e a r l y w o o d - l a t e w o o d t r a n s i t i o n . Spec i e s h a v i n g t y p i c a l l y abrupt t r a n s i t i o n tended to d i s p l a y a r a t h e r s i g m o i d a l p a t t e r n of <^ >^  - c e l l u l o s e y i e l d , w h e r e a s those hav ing t y p i c a l l y g r a d u a l t r a n -s i t i on show a f latter p a t t e r n 4. U s i n g t h r e e v a r i a b l e s of wood qual i ty , a l p h a - c e l l u l o s e content throughout m a t u r e growth i n c r e m e n t s m a y be p r e d i c t e d r e l i a b l y b y l i n e a r r e g r e s s i o n o r , m o r e a c c u r a t e l y , b y l o g a r i t h m i c t r a n s -f o r m a t i o n . In two e x a m p l e s , b l a c k s p r u c e and Douglas f i r , c o r r e -l a t i o n coef f ic ients d e t e r m i n e d b y the la t t er m e t h o d w e r e 0 .95 and 0 .96 , r e s p e c t i v e l y . T h i s s u c c e s s f u l a p p l i c a t i o n of a l o g a r i t h m i c t r a n s f o r m a t i o n i s i ts f i r s t r e p o r t e d use d e s c r i b i n g the n o n - l i n e a r b e h a v i o r of a wood c h e m i c a l p r o p e r t y a c r o s s a con i f erous i n c r e m e n t . 5. E x a m i n a t i o n of < ^ - c e l l u l o s e and l i g n i f i c a t i o n pa t t erns i n the s a m e growth zones showed the ^ - c e l l u l o s e e s t imate (x = 45. 9 + 2. 0%) as the exact c o m p l e m e n t of l i g n i f i c a t i o n (x = 2 7 . 4 + 1.9%), r e g a r d -l e s s of spec i e s or l o c a t i o n wi th in growth zone (hence, s e a s o n of f o r m a t i o n ) . E v i d e n c e suppor t ing this i m p o r t a n t i n t e r r e l a t i o n s h i p was d e m o n s t r a t e d b y l i n e a r c o r r e l a t i o n ; for 60 p a i r s of o<^ - c e l l u l o s e - l i g n i n va lues , r = - 0 . 7 8 5 was h i g h l y s ign i f i cant . T h i s c o r r e l a t i o n r e i n f o r c e s p r e v i o u s t h e o r y on the m u t u a l l y 106 e x c l u s i v e na ture e x i s t i n g between l i g n i n and c e l l u l o s e . 6. F u r t h e r ev idence of the m u t u a l l y e x c l u s i v e n a t u r e of - c e l l u l o s e and l i g n i n r e s u l t e d when the m i c r o l i g n i n and o<* - c e l l u l o s e va lues w e r e c o m b i n e d . T h e s e va lues c l u s t e r e d about a c e n t r a l va lue (x = 73 .4 +_ 1. 2%), sugges t ing that for the i n c r e m e n t s s tudied, a c o m m o n , c r i t i c a l p o r t i o n of h igh m o l e c u l a r weight m a t e r i a l was i n c l u d e d i n c e l l w a l l f o r m a t i o n . F u r t h e r m o r e , d i s p e r s i o n about the c o m b i n e d value's was s i g n i f i c a n t l y l e s s than that about e i ther of t h e i r i n d i v i d u a l m e a n s . T h i s suggests c l o s e r p h y s i o l o g i c a l c o n t r o l o v e r - c e l l u l o s e and l i g n i n when c o m b i n e d , i n d i c a t i n g that t r e e p h y s i o l o g y i s o r i e n t e d m o r e towards the f i n i s h e d b i o -synthet ic p r o d u c t than towards the i n d i v i d u a l components i n v o l v e d i n s u c h a s y s t e m . n i t r o c e l l u l o s e c h a i n - l e n g t h v a r i a t i o n w e r e evident throughout growth zones . H o w e v e r , i n four i n c r e m e n t s , s ign i f i cant d i f f erences i n Jj^ l throughout the e a r l y w o o d p r o v i d e d fur ther ev idence of two e a r l y w o o d t y p e s . 7. B e c a u s e of the h i g h l y v a r i a b l e at each p o s i t i o n , no t r e n d s i n B I B L I O G R A P H Y A b a d i e , F . A . and 0. E l l e f s e n . 1952. 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C h l o r i t e h o l o c e l l u l o s e , its f r a c t i o n a t i o n and b e a r i n g on s u m m a t i v e wood a n a l y s i s and on studies on the he m i c e l l u l o s e s . P a p e r T r a d e J . 122(2) : 35-43. 154. W o r r a l l , J . G . 1963. T h e r e l a t i o n s h i p between f r a c t i o n a l v o i d v o l u m e and wood qua l i ty i n w e s t e r n C a n a d i a n c o n i f e r s . Unpub . T h e s i s . F a c . F o r . U n i v . B r i t . C o l . , V a n c o u v e r , B . C . 155. W u , Y . T . 1963. I n t r a - i n c r e m e n t m e t h o x y l content of f ive w e s t e r n C a n a d i a n woods . Unpub . p a p e r . F a c . F o r . U n i v . B r i t . C o l . , V a n c o u v e r , B . C . 156. . 1964. I n t r a - i n c r e m e n t l i g n i n content of f ive w e s t e r n C a n a d i a n con i f erous woods . Unpub. T h e s i s . F a c . F o r . U n i v . B r i t . C o l . , V a n c o u v e r , B . C . 157. and J . W . W i l s o n . 1967. L i g n i f i c a t i o n wi th in con i f erous growth zones . P u l p P a p e r M a g . C a n . 68 : T159 - T 1 6 4 . 158. Z a h n e r , R . 1962. T e r m i n a l growth and wood f o r m a t i o n b y juven i l e l o b l o l l y p ine under two s o i l m o i s t u r e r e g i m e s . F o r e s t S c i . 8 : 345-352. 159. • 1963. In terna l m o i s t u r e s t r e s s and wood f o r m a t i o n i n c o n i f e r s . F o r e s t P r o d . J . 13 : 240-247. 160. Z o b e l , B . J . and R . L . M c E l w e e . 1958. V a r i a t i o n of c e l l u l o s e i n l o b l o l l y p ine . T a p p i 41 : 167-170. T A B L E S A N D F I G U R E S T A B L E 1. A n a l y s e s on c o n i f e r o u s e a r l y w o o d ( E ) , l a tewood ( L ) , and whole wood (W) c a r b o h y d r a t e f r a c t i o n s f r o m the l i t e r a t u r e (based on o v e n - d r y , e x t r a c t i v e - f r e e wood). 121 . N o . . N o . o*C - C e l l u l o s e H o l o c e l l u l ose , . .Species Ref . S tems P a i r s b y n i t r a t i o n , % % ' E L W P i n u s m o n t i e o l a Doug l . i o i b 1 1 57-60 P i n u s r e s i n o s a A i t . 5 3 ° 1 1 73. 2 74.8 76 2 24 P i n u s s y l v e s t r i s L . 8 9 h P i n u s p o n d e r o s a L a w s . i o i b 4 2 56-59 P i n u s b a n k s i a n a L a m b . 130 41. 3 P i n u s p a l u s t r i s M i l l . 1 0 6 b •f 4 1 55-61 P i n u s t a e d a L . 160, 125 "U' 500 77-84 1 0 2 b l h 1 P i n u s d e n s i f l o r a S. et Z . 55 4 4 P i c e a ab ie s ( L . ) K a r s t 52S 1 51 P i c e a g l a u c a (Moench) V o s s 106 4 1 60-63 130, 46. 0 L a r i x o c c i d e n t a l i s Nutt . 1 0 6 b 4 1 53-61 130 4 3 .8 P s e u d o t s u g a m e n z i e s i i 5 3 ° 1 1 70 . 9 7 5 . 3 69-68 ( M i r b . ) F r a n c o 6 8 b 3 2 71-77 1 0 2 ° 1 1 1 0 6 b 4 1 57-64 T s u g a c a n a d e n s i s ( L . ) C a r r . 130 41. 3 A b i e s a m a b i l i s (Doug . ) F o r b . 130 48. 5 S e q u o i a s e m p e r v i r e n s ( D . D o n . ) : 106 b 4 2 48 E n d l . L i b o c e d r u s d e c u r r e n s T o r r . 1 0 6 b 4 2 40-44 T h u j a o c c i d e n t a l i s L . 130 44. 6 C h a m a e c y p a r i s nootkatens i s i o i b 4 2 51-55 <^<- C e l l u l o s e , ( D . D o n . ) S p a c h % * L W 44 45 .3 53 .0 39 45 52-57 58 .0 61 .2 37. 0-40. 3 42. 8 -43 . 5 56 .0 59 .4 48 48 46-48 45-51 45 47 38 20 49 36 H y d r o l y z a t e s , • % .a a G-E M L G M 4 7 . 8 1 1 . 0 d 49 .9 1 3 . 9 d 56. 7 20 . 3 e 56. 2 24. 8 e a) G = g l u c o s e , M = m a n n o s e b) after C r o s s and B e v a n (33): c) a f ter W i s e et a l . (153) d) b y c a l c u l a t i o n e) as g l u c o m a n n a n f) a f ter Y u n d t and B r a d w a y (160) g) su l f i te pu lp spec ie s p r o b a b l y E u r o p e a n s p e c i e s h) sapwood 122 T A B L E 2. D e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r on <=>< - c e l l u l o s e y i e l d for 40-60 m e s h Douglas f i r l a t ewood m e a l u s i n g t h r e e s a m p l e s i z e s ( n i t r o c e l l u l o s e s c o r r e c t e d to 13.65 + 0. 30% n i trogen) . S a m p l e s i ze (g o v e n - d r y ) I t em 0. 05 0. 10 0 .20 1 47. 2 51. 2 51. 5 2 48. 5 51. 0 50. 6 3 43. 9 51. 0 51. 1 4 45. 4 50. 3 50. 6 5 47. 6 50. 3 51. 6 m e a n (x)j % 46. 5 50. 8 51. 1 v a r i a n c e (s ) 3 .4 0. 20 0 .23 r e p l i c a t i o n no. (n) ; 4. 3 2. 4 2 .9 T o t a l s a m p l e r e q u i r e d , g 2. 2 . 3 . 6 R e p l i c a t i o n n u m b e r was d e t e r m i n e d b y Stein's t w o - w a y s a m p l i n g technique r e p l i c a t i o n n u m b e r h a l f - w i d t h of d e s i r e d conf idence i n t e r v a l s a m p l e v a r i a n c e tabulated t for a 90% conf idence i n t e r v a l (1, 4),= t 2 = 4. 54 (116): 2 2 \ S n = C 1 3 w h e r e : n d = s = (4. 54) (s %): (0 .6%) 2 t , = T A B L E 3. D e t e r m i n a t i o n of r e p l i c a t i o n n u m b e r for Douglas la tewood n i t r o c e l l u l o s e n i t r o g e n content. I t em E s t i m a t e d N i t r o g e n Content, % 1 13.80 2 13.82 3 13.77 4 13.70 5 13.83 x 13.78 S 2 0.0027 n 1.92 R e p l i c a t i o n n u m b e r was d e t e r m i n e d b y Stein's 2 - w a y s a m p l i n g technique (116) as i n T a b l e 2. - t 4' 54> '• ° ° 2 7 » C 3 D d (0.08) 124 T A B L E 4. • S u m m a r y of a l p h a - c e l l u l o s e and l i g n i n e s t i m a t e s and n i t r o c e l l u l o s e v i s c o s i t i e s for ten c o n i f e r o u s i n c r e m e n t s e x a m i n e d . S p e c i e s S t e m N o . I n c r e -ment N o . P o s i -t i o n E s t i m a t e d alpha-c e l l u l o s e , % r e p l i c a t i o n s E s t i m a t e d l ignin. , r e p s . X A l p h a - c e l l u l o s e N i t r o c e l l u l o s e v i s c o s i t y p lus L i g n i n x _(7 d l / j e s t i m a t e s , % r e p l i c a t i o n s x 1 47. 5 47. 1 46. 6 46. 5 46. 9 2 6 . 6 2 6 . 9 2 6 . 7 73. 6 30. 2 31.2 31. 6 31. 0 2 48. 0 47. 6 47. 5 47. 7 26. 0 26. 2 26. 1 73. 8 29. 9 27. 6 26. 5 28. 0 3 48. 6 48. 5 47. 8 48. 0 48. 2 25. 5 25. 7 25. 6 73. 8 26. 3 26. 4 26. 7 26. 5 4 49. 8 50. 1 49- 7 49. 2 49. 7 25. 0 24. 8 24. 9 74. 6 28. 5 28. 9 2 9 . 4 30. 0 29. 2 5 49. 6 50. 1 49-9 49.9 :2r5.."5 25. 3 25. 4 7 5. 3 29. 3 30. 9 33. 8 34. 2 32. 1 6 47. 6 47. 8 47. 5 47. 6 25. 4 25. 6 25. 5 73. 1 28. 5 30. 5 30. 5 30. 6 30. 0 1 43. 1 43. 5 43. 6 4 3 . 4 30. 3 30. 5 30. 4 7 3 .8 35. 5 36. 0 36. 7 36. 1 2 44. 0 44. 7 45. 0 44. 6 30. 4 30. 5 30. 5 75. 1 32. 1 34. 2 36. 6 34. 3 3 44. 9 44. 7 45. 0 44. 8 29. 7 29. 3 29. 5 74..3 34. 3 35. 8 35. 1 4 45. 5 46. 1 46. 1 45. 9 28. 9 29. 3 29. 1 75. 0 36. 2 37. 3 38. 8 37. 4 5 47. 0 46. 8 46. 5 46. 8 28. 6 28. 6 28.6 75..4 37. 3 38. 6 38. 0 6 45. 8 46. 0 46. 0 46. 0 29. 1 28. 7 28. 9 74..9 34. 8 35. 0 36. 4 35 .4 1 46. 2 46. 3 46. 8 46.4 27. 4 27. 2 27. 3 7 3 . 7 33. 5 33. 8 34. 0 2 46. 3 45. 9 45. 8 46. 0 27. 4 27. 9 27. 6 73. 6 30. 8 31 .7 33. 6 3 47. 2 47. 1 47. 7 47. 3 2 6 . 4 2 6 . 4 2 6 . 4 73. 7 32. 2 33. 5 33. 7 4 47. 6 47. 6 47. 3 47. 5 26. 2 26. 5 26. 4 73 .9 28. 5 32. 5 5 47. 7 47. 2 48. 1 47. 7 26. 0 25. 8 25.8 73. 5 30. 3 33. 4 6 47. 4 48. 3 47. 4 47. 7 25. 2 25. 2 25. 2 72. 9 35. 3 36. 7 1 44. 6 43. 4 43. 9 44. 0 28. 4 28. 7 28. 5 72. 5 34. 9 35. 3 36. 8 2 45. 7 44. 8 45. 1 45. 2 45. 2 28. 7 28. 6 28. 7 73. 9 32. 1 32. 6 35. 5 3 46. 1 46. 4 46. 3 46. 2 27. 8 27. 4 27. 6 73. 8 3.1. 9 32. 1 33. 3 4 46. 8 48. 5 47. 7 47. 7 26. 5 26. 5 26. 5 74. 2 32. 4 33. 0 5 48. 1 49. 1 49- 0 49. 7 49. 0 26. 0 25. 9 26. 0 75. 0 34. 0 35. 2 37. 5 6 49. 1 48. 2 49- 1 48. 8 25. 3 25. 2 25. 3 74. 1 31. 7 32. 2 34. 8 1 44. 5 44. 0 44. 3 44. 3 27. 1 27. 1 27. 1 71 .4 35. 9 37. 5 38. 5 2 43. 4 44. 1 44. 1 43. 9 28. 6 2,8. 3 28. 4 72. 3 34. 9 35. 0 36. 5 3 46. 1 46. 5 47. 1 46. 8 46. 6 26. 0 25. 8 26. 0 72. 6 31. 1 32. 5 35. 6 4 47. 1 46. 9 47. 7 46. 9 26. 6 26. 7 26. 7 73. 6 32. 5 33. 1 5- 47. 3 46. 9 47. 6. 47. 3 25. 7 25. 9 25. 8 73. 1 32. 2 36. 6 37. 2 6 48 .2 47. 6 48. 7 48. 2 24. 9 25. 2 25. 1 73. 3 34. 1 34 .9 39. 2 1 45. 2 45. 5 44. 8 45. 2 29. 1 29. 1 74. 3 25. 1 26. 4 2 44. 5 43. 4 44. 0 44. 0 31. 1 30. 3 30. 7 74. 7 24. 5 26. 0 3 46. 7 46. 4 45. 5 46. 2 28. 4 28. 8 28.6 74. 8 27. 6 2 6 . 8 33. 0 31 6 4 47. 6 47. 2 48. 0 47. 6 2 6 . 4 26. 4 74. 0 24. 1 25. 8 5 49. 0 49. 4 49- 8 49. 4 25. 8 25. 7 25. 8 75. 2 30. 5 30. 6 29. 0 6 48. 7 47. 4 47. 3 47. 8 25. 9 2 6 . 1 2 6 . 0 73. 8 30. 8 30. 6 29. 6 1 43. 9 42. 4 43. 3 43. 2 28. 7 29. 3 29.0 72. 2 36. 2 32. 2 30. 0 2 43. 2 43. 9 43. 6 43. 6 28. 3 28. 4 28. 3 7 1 . 9 32. 8 32. 8 33. 4 3 45. 5 45. 0 44. 7 45. 1 27. 8 27. 5 27. 7 72. 8 29. 1 31.2 31. 5 32 8 4 46. 4 46. 1 47. 0 46. 5 2 6 . 6 2 6 . 7 2 6 . 6 73. 1 29. 7 33. 8 34. 1 5 47. 4 47. 4 47. 3 46. 7 47. 2 2 6 . 4 2 6 . 0 2 6:'2 73. 4 25. 9 28. 0 28. 4 30 8 6 46. 6 46. 9 46. 4 46. 6 2 6 . 3 2 6 . 2 26. 2 72. 8 32. 6 31. 0 24. 9 1 44. 6 43. 8 44. 3 *44. 3 27. 7 27. 9 27. 8 72. 1 31. 5 27. 9 2 4 2 . 8 43. 2 43. 9 *43. 2 29. 0 29. 0 29. 0 72. 2 28. 4 P i c e a s i t c h e n s i s 70 ( B o n g . ) C a r r P i c e a m a r i a n a 34 ( M i l l . ) B . S. P . P s e u d o t s u g a  m e n z i e s i i ( M i r b . ) F r a n c o 64 65 66 40 A b i e s a m a b i l i s 78 ( D o u g l . ) F o r b 79 125 T A B L E 4 (Cont inued) S p e c i e s S t e m N o . Incre -ment N o . P o s i -t i o n E s t i m a t e d a lpha-c e l l u l o s e , r e p l i c a t i o n s x E s t i m a t e d A l p h a - c e l l u l o s e N i t r o c e l l u l o s e v i s c o s i t y l i g n i n , % plus L i g n i n x jjffl r e p s x e s t i m a t e s , % r e p l i c a t i o n s x A b i e s a m a b i l i s ( D o u g l . ) F o r b . 73 80 T h u j a p l i c a t a Donn 73 3 44. 5 44. 1 45. 2 44. 6 27. 7 27. 9 27. 8 72. 4 28. 4 28. 6 30. 3 4 45. 5 46. 6 45. 7 46. 7 46. 1 27. 3 27. 1 27. 2 73. 3 33. 2 33. 8 5 46. 7 46. 9 47. 5 46. 7 47. 0 26 .4 26. 8 26. 6 73. 6 34 .2 35. 5 29. 6 30. 3 6 45. 8 47. 1 46. 9 4 6 . 6 26. 0 26. 5 26. 2 72. 8 30 .4 26. 2 1 43. 3 41. 8 42. 0 42. 5 42. 5 28. 9 28. 5 28. 7 71. 2 30. 8 34. 1 34. 5 2 42. 1 42. 2 42. 3 *42. 2 29. 1 29. 2 29. 2 71. 4 32. 9 31. 5 31. 6 3 43. 0 43. 3 43. 3 43. 5 *43. 3 28. 2 28. 3 28. 2 71. 5 28. 0 30. 7 32. 7 4 45. 2 45. 1 44. 1 44. 8 27. 6 27. 6 27. 6 72. 4 30. 8 31. 4 31 .7 5 46. 0 46. 3 45. 3 45. 9 26. 6 26. 4 26. 5 72. 4 28. 5 30. 4 31. 3 6 44. 8 45. 6 45. 6 45. 3 26. 2 26. 5 26. 4 71. 7 27. 7 29. 4 1 40. 2 41 .2 40. 6 *40. 7 31 .7 32. 4 32. 0* 72. 7 32. 0 32. 4 30. 6 30. 0 30. 4 31. 1 2 43. 0 42. 6 42. 7 42. 8 32. 8 32. 6 32. 7 75. 5 31. 8 28. 1 28. 5 29. 5 3 44. 2 44. 0 44. 3 44. 2 31. 5 31. 6 3 1 . 5 75. 7 28. 0 29. 2 28. 6 4 44. 9 45. 3 45. 5 45. 2 30. 7 30. 3 30. 5 75. 7 26. 5 27. 8 28. 3 27. 5 5 45. 3 45. 9 45. 3 45. 5 30. 6 30. 8 30. 7 76. 2 28. 6 28. 8 30. 6 32. 7 33. 0 30. 7 6 45. 7 46. 0 45. 5 45. 7 29. 8 29. 6 29. 7 75. 4 30. 1 32. 0 29. 7 30. 6 N x , % s, % 60 45. 9 1. 98 60 27. 6 1.95 60 73. 5 1. 23 a) P o s i t i o n 1 = f i r s t - f o r m e d e a r l y w o o d ; p o s i t i o n 6 = l a s t - f o r m e d la tewood . * r e p e a t e d v a l u e 126 T A B L E 5. L i n e a r r e g r e s s i o n of a l p h a - c e l l u l o s e e s t imate s ( Y , %) on p o s i t i o n (X) for a l l spec ies and i n c r e m e n t s . P i c e a s i t chens i s ( B o n g . ) C a r r . I n c r e m e n t N o . 70 Y = 47 .17 + .33 X n = 6 r = . 5 1 S E = 1.2 E P i c e a m a r i a n a ( M i l l . ) B . S. P . I n c r e m e n t N o . 34 Y = 43. 19 + . 59 X n = 6 r = . 9 0 * S E = . 72 E P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40 Y = 43 .64 + . 8 7 X n = 6 r=. 83* - S E = 1 . 2 I n c r e m e n t N o . 64 to 66 Y = 44. 08 + . 75 X n = 18 r = . 8 6 * * S E = . 8 8 E A b i e s a m a b i l i s ( D o u g l . ) F o r b . I n c r e m e n t s N o . 78 to 80 Y = 42 .22 + . 7 6 X n = 18 r = . 83** S E = . 3 4 E T h u j a p l i c a t a Donn. I n c r e m e n t N o . 7 3 Y = 40 .62 + .97 X n = 6 r = . 9 3 * * S E = . 7 8 E * * h i g h l y s ign i f i cant * s ign i f i cant 127 T A B L E 6. A n a l y s i s of v a r i a n c e for a lpha-oe l lu lose e s t imates (%) wi th in P i c e a m a r i a n a ( M i l l . ) B . S. P . I n c r e m e n t N o . 34. F F . 01 S o u r c e df_ ss M S A m o n g pos i t i ons 5 21. 67 4. 33 W i t h i n pos i t i ons 12 1. 12 0. 093 T o t a l 17 22. 79 4 7 . 4 1 * * 5.06 * * h i g h l y s ign i f i cant T A B L E 6 A . Duncan ' s test of m e a n a l p h a - c e l l u l o s e e s t imates (%) wi th in P i c e a m a r i a n a ( M i l l . ) B . S . P . I n c r e m e n t N o . 34. P o s i t i o n 1 2 3 4 6 5 A l p h a - c e l l u l o s e 43 .40 45. 57 44 .87 45 .90 45 .93 46 .77 no s ign i f i cant d i f f erence between m e a n s . T A B L E 7 . A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in P i c e a s i t c h e n s i s ( B o n g . ) C a r r . I n c r e m e n t N o . 70. S o u r c e df ss M S F F . 01 A m o n g pos i t i ons 5 20 .03 4 .07 3 4 . 2 7 * * 5. 06 W i t h i n pos i t i ons 12 1.40 0 .117 T o t a l 17 21 .43 128 T A B L E 7 A . Duncan ' s test of m e a n a l p h a - c e l l u l o s e e s t imates (%) wi th in P i c e a s i t chens i s ( B o n g . ) C a r r . I n c r e m e n t N o . 70. P o s i t i o n 1 6 2 3 4 5 A l p h a - c e l l u l o s e 47 .07 47. 64 47. 70 48. 10 49 .67 49 .87 T A B L E 8, A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t i m a t e s (%) wi th in T h u j a p l i c a t a Donn. I n c r e m e n t N o . 73 . S o u r c e df ss M S F F . 01 A m o n g pos i t i ons 5 58.29 11.66 116 .6** 5 .06 W i t h i n pos i t i ons 12 1.21 0 .10 T o t a l 17 59-50 T A B L E 8 A . Duncan ' s test of m e a n a l p h a - c e l l u l o s e e s t imates (%) wi th in T h u j a p l i c a t a Donn I n c r e m e n t N o . 73 . P o s i t i o n 1 2 3 4 5 6 A l p h a - c e l l u l o s e 40 .67 42 .77 44 .17 45 .23 45 .50 45 .73 T A B L E 9. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imates (%) wi th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40. S o u r c e df ss M S F F . 01 A m o n g pos i t i ons 5 58 .14 11.63 39. 83** 5.06 W i t h i n pos i t i ons 12 3 .50 0 .29 T o t a l 17 61 .64 129 T A B L E 9 A Duncan's test of m e a n a l p h a - c e l l u l o s e e s t imates (%) within P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40 . P o s i t i o n 2 1 3 4 6 5 A l p h a - c e l l u l o s e 43 .96 45 .17 46 .20 47 .60 47 .80 49 .40 T A B L E 10. A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imates (%) wi th in P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o Increments N o . 64 to 66. S o u r c e P o s i t i o n I n c r e m e n t P x I E r r o r T o t a l df 5 2 10 38 55 as M S F . 01 158.05 31.61 131. 3** 3 .54 2.921 1.46 6 .06**5 .23 14.194 1.42 9. 151 184.32 5. 89**2. 84 241 T A B L E 10A. Duncan's test of m e a n a l p h a - c e l l u l o s e e s t imates (%) within P s e u d o t s u g a m e n z i e s i i ( M i r b . ) ; F r a n c o I n c r e m e n t s N o . 64 to 66. P o s i t i o n 1 A l p h a - c e l l u l o s e 44. 89 44 .97 46 .73 47 .46 48 .07 48 .22 I n c r e m e n t 66 . 65 64 A l p h a - c e l l u l o s e 46 .26 46 .83 47 .11 130 T A B L E 11 . A n a l y s i s of v a r i a n c e for a l p h a - c e l l u l o s e e s t imate s (%) wi th in A b j es a m a b i l i s ( D o u g l . ) F o r b . I n c r e m e n t s N o . 78 to 80 . S o u r c e P o s i t i o n I n c r e m e n t P x I E r r o r T o t a l df_ 5 2 10 42 59 ss M S F . 01 130. 86 26. 17 108. 6** 5. 16 33. 66 16. 83 69. 80**3. 48 - 9 . 2 9 - 0 . 9 3 - 3 . 8 5 2 .78 10.13 .241 165.36 T A B L E 11 A . Duncan ' s test of m e a n a l p h a - c e l l u l o s e e s t imates (%) within A b i e s a m a b i l i s (Doug l . ) F o r b . I n c r e m e n t s N o . 78 to 80. P o s i t i o n 1 2 3 4 5 6 A l p h a - c e l l u l o s e 43 .05 43 .34 44. 31 45. 82 46 .19 46 .76 I n c r e m e n t 80 79 78 A l p h a - c e l l u l o s e 44.01 45 .28 45 .39 131 T A B L E 12 . L i n e a r r e g r e s s i o n of l i g n i n (-Y, %) on a l p h a - c e l l u l o s e e s t imate s (X, %) for a l l spec i e s and i n c r e m e n t s . P i c e a s i t chens i s ( B o n g . ) C a r r . I n c r e m e n t N o . 70 Y = 46. 10 - . 4 2 2 X n = 6 r=-% 820* S E £ = . 40 P i c e a m a r i a n a ( M i l l . ) B . S. P . I n c r e m e n t N o . 34 Y = 56. 42 - . 595X n = 6 r=-w921** S E = . 36 E P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o I n c r e m e n t N o . 40 Y = 75. 73 -• 1. 0 3 X n = 6 r = - 934** S E = . 86 E I n c r e m e n t s N o . 64 to 66 Y = 57. 32 - . 660X n =• 18 r=-w 764** S E = . 8 1 E A b i e s a m a b i l i s ( D o u g l . ) F o r b . I n c r e m e n t s N o . 78 to 80 Y = 55. 43 - . 622X n « 18 r = — 9 4 5 * * S E =.92 E T h u j a p l i c a t a Donn Increment? N o . 73 Y = 48. 61 - . 397 X n = 6 r = - . 733 ( N . S . ) S E =. 80 E N . S. = not s ign i f i cant 132 T A B L E 13. C o r r e l a t i o n coef f ic ients (r) f r o m the l i n e a r r e g r e s s i o n of j/fl ( d l / g ) on a l p h a - c e l l u l o s e y i e l d (%) for s ix i n t r a - i n c r e m e n t p o s i t i o n s , showing effect of i n c l u s i o n (+) o r e x c l u s i o n (-) of data f r o m P o s i t i o n N o . one (which c o r r e s p o n d s to f i r s t - f o r m e d ear lywood) . S p e c i e s I n c r e m e n t + P i c e a s i t chens i s ( B o n g . ) C a r r . 70 .07 .42 P i c e a m a r i a n a ( M i l l . ) B . S. P . 34 .49 . 7 4 * * P s e u d o t s u g a m e n z i e s i i ( M i r b . ) F r a n c o 66 - . 1 0 .71 * T h u j a p l i c a t a Donn 73 - . 5 6 * .28 * * h i g h l y s ign i f i cant * s ign i f i cant 1 exc ludes P o s i t i o n N o . 2 a l so 133 Pseudotsuga menziesii Picea mariana (Mill) B S P ( Mirb) Franco Position Position I I L - — J 1 I L _ — J ' i i i i i i i 0 1 2 3 0 I 2 3 Radial Distance,mm-F i g u r e 1. T w o r e p r e s e n t a t i v e pat terns of a l p h a - c e l l u l o s e (es t . ) ; %• 134 Picea mariona (Mill)BSP-® Lignin plus Alpho Cellulose (est),% X Alpha Cellulose (es1),% O Lignin ,% 1§§§H§ Eorlywood i i i Lotewood i i 0 2 3 4 Radiol Distance , mm-Pseudotsuga menziesii (Mirb)Franco 76 Picea sitchensis (Bong)Carr-Abies amabilis (Dougl) Forb Thuja plicata Donn 7 6 -F i g u r e 2. T e n pat terns showing a l p h a - c e l l u l o s e (es t . ) , %, l i g n i n , %, and t h e i r s u m . 136 24 34 70 64 65 66 40 78 79 80 73 Increment Number F i g u r e 4. M e a n s (x) and s t a n d a r d deviat ions (S) for a l l a lpha-c e l l u l o s e and l i g n i n e s t imate s and the ir s u m . A P P E N D I C E S A P P E N D I X I. _ R e l a t i o n s h i p between the m a j o r c e l l w a l l components after N o r m a n (94). C e l l W a l l Components C h l o r i t e H o l o c e l l u l o s e C r o s s and B e v a n "Plant C e l l u l o s e " H E M I C E L L U L O S E tiydrolyzed by di lute a c i d ( so luble i n di lute a l k a l i ) ^ T R U E C E L L U L O S E ( l o n g - c h a i n 1, 4 - / ? - D -a n h y d r o - g l u c o p y r a n o s e units) o r i e n t e d . C E L L U L O S A N S ( c e l l u l o s i c f r a m e w o r k substance) x y l a n m a n n a n glucans o r i e n t e d P O L Y U R O N I D E H E M I C E L L U L O S E ( e n c r u s t i n g substance) M e t h o x y h e x u r o n i c a c i d Pentose : x y l o s e a r a b i n o s e H e x o s e : g lucose ga lac tose amorphous L I G N I N (non c a r b o -hydrate ) - p h e n y l p r o p a n e units - pheno l i c and eno l i c h y d r o x y l s a m o r p h o u s 139 A P P E N D I X II. Suggested g e n e r i c c l a s s i f i c a t i o n of wood p o l y s a c c h a r i d e s after S tewart (117). G l y c o s a n u r o n i d e s P o l y s a c c h a r i d e s N o n - c e l l u l o s i c g lycosans N o n - g l u c o s i c c e l l u l o s i c g lycosans G l y c o s a n s C e l l u l o s i c g l y c o s a n s G l u c o s i c cel lulosje g l y c o s a n s A P P E N D I X III. D e s c r i p t i o n of s t e m sections and growth i n c r e m e n t s i n c l u d e d i n the study (157). S t e m Sec t ion G r o w t h Increments Spec i e s C h a r a c t e r i s t i c s E x a m i n e d A g e , D i a , S t e m D e c a d a l N o . G r o w t h L a t e w o o d y r i n G r o w t h G r o w t h , Rate , % Rate , m m / y r m m / y r m m / y r P i c e a s i t c h e n s i s ( B o n g . ) C a r r . 92 16 .4 2 .3 1. 7 70 2. 2 18. 9 P i c e a m a r i a n a ( M i l l . ) B . S . P . a 34 3 .4 43. 0 P s e u d o t s u g a m e n z i e s i i ( M i r b . ) 77 19.2 3.2 2. 5 64 2. 4 45. 8 F r a n c o 65 2. 8 44. 3 66 2. 2 41. 0 P s e u d o t s u g a m e n z i e s i i 4 0 a 3.6 44. 0 ( M i r b . ) F r a n c o A b i e s a m a b i l i s ( D o u g l . ) F o r b . 143 23 .0 2 .0 3. 5 7 8 a 3. 5 20 .9 79 3. 1 15. 6 80 2. 7 19. 2 T h u j a p l i c a t a Donn 78 18.9 3.1 1.9 73 2. 3 20. 7 a) H e a r t w o o d zone, a l l o ther s a m p l e s f r o m sapwood. 

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