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T H E JOURNAL OF INDUSTRIAL A N D ENGINEERING CHEMISTRY
reflected light is unaffected b y t h e d e p t h of color of t h e paper, while t h e amount of diffusely reflected light is diminished, depending on t h e depth of t h e shade of t h e paper. T h e increase i n per cent glare caused b y calendering is shown b y t h e typical glare curves, as plotted i n t h e figure for dyeings made with rarious amounts of Safranine T extra Conc., on a furnish of 80 per cent groundwood a n d 2 0 per cent unbleached sulfite. T h e per cent glare of t h e blank made f r o m t h e same furnish as t h e dyed samp,les increased from 18.8 t o 38.7 t o 51.4 per cent with t h e successive calenderings. T h e effect of t h e color in increasing t h e per cent glare reading b y causing absorption of some of t h e light is evid e n t from a s t u d y of t h e curve.
Vol. 9 , No. 3
reflected. With t h e same finish b u t with increase in color, t h i s causes a n a p p a r e n t increase in per cent glare. With t h e present design of t h e glarimeter, uniform lighting conditions are secured b y a n incandescent light within t h e light-proof interior of t h e instrument, while lighting conditions for t h e t i n t photometer are secured from daylight. I n trying t o check relations between t h e t w o instruments, t h e color screens of t h e t i n t photometer were later attached t o t h e objective of t h e glarimeter while readings were being taken b u t t h e results secured were very erratic. T h u s while t h e glarimeter might be found of value in determining t h e finish of.white papers, in t h e light of our d a t a i t could not be recommended for colored papers of differe n t hues a n d intensities. FORESTPRODUCTS LABORATORY MADISON, WISCONSIN
THE CHEMISTRY OF WOOD DECAY PAPER I-INTRODUCTORY BY ROBERTEVSTAPIEPP ROSEAND MARTINWILLIAM LISSE~ Received A-ovember 2 7 , 1916
LBIIOFDYE PER IO00 LBS.OfDRY STOCK. We h a v e shown t h a t i t is possible t o give a numerical expression for both shade a n d d e p t h of color b y means of t h e t i n t photometer a n d t h a t t w o dyeings which match visually, will, within t h e allowable experimental error, match under t h e I v e s T i n t Photometer eventhough t h e t w o matches were dyed with different dyestuffs. F o r white sheets i t is possible t o follow t h e progress of calendering b o t h b y t h e t i n t photometer i n recording t h e increase i n parts black of t h e paper or b y t h e decrease i n parts red, blue, or green, a n d b y t h e glarimeter i n recording t h e increase i n per cent glare. For colored papers t h e t i n t photometer will record t h e increase i n p a r t s black for successive production of finish b y calendering, b u t t h e per cent glare will increase, not only due t o t h e finish of t h e paper itself, b u t also due t o t h e fact t h a t with darkening of t h e paper t h e a m o u n t of diffusely reflected light is decreased without changing t h e a m o u n t of light “specularly”
During t h e decay of wood t h e composition of t h e material obviously undergoes profound alteration. By slow changes t h e structure of t h e wood is destroyed, t h e macroscopic changes being accompanied b y a corresponding chemical disintegration. T h e highly complex compounds originally present pass into others of increasing simplicity until a t last ail passes i n t o carbon dioxide, water, perhaps also hydrogen a n d methane. Between wood a n d its ultimate dissolution products must lie a whole range of intermediate substances. T h e chemistry of t h e process has received b u t scant attention, though i t should prove of interest, as a scientific s t u d y , a n d as a prerequisite t o discovering possible uses for a waste product occurring i n great q u a n t i t y . T h e subject has been merely touched upon in t h e work of Omelianski.2 while t h e efforts made t o determine t h e n a t u r e of humus a n d i t s components bear only distantly upon t h e question of wood decay, although t h e results obtained should prove valuable i n determining t h e n a t u r e of t h e substances i n very rotten wood.3 T h e very nearest approach t o t h e subject has been made b y Schreiner a n d Sullivan,4 who have identified some products obtained from rotten wood a n d peat. It is clearly no easy t a s k t o determine t h e chemical changes undergone during t h e disintegration of wood under natural conditions; t h e transition of t h e material is a slow one unsuited t o laboratory s t u d y ; t h e accompanying conditions vary very greatly, a n d t h e products formed are largely lost as gases or as water-soluble compounds. Moreover, inasmuch as decay is due t o t h e activity of lower vegetative forms, t h e n a t u r e of t h e bacteria, fungus or fungi responsible will largely modify t h e outcome. 1 Used by hl. W. Lisse in part fulfillment of the requirements for the h1.S. degree in the University of Washington. 2 Compt. vend., 121 (1895), 653; 125, 970, 1131; Archiv Scienc hzoloq, 7, 411; 9 , No. 3 ; Centv. Bakf., 8 (111, 193; 11, 370 and 703. a Compare Czapek, “Die Biochemie der Pflanzen,” Vol. I, pp. 226-229. 4Sullivan, THISJOURNAL, 6 (1914), 919, and 8, 1027: 0. Schreiner and E. C. Shorey, U. S. Dept. Agr., Bureau of Soils. Bull. 74, 1914; Sullivan, Science, 38 (1913), 678.
-4-VD E N G I L V E E R T ~ T GC H E J I I S T R Y Realizing t h e many uncontrolled, not necessarily uncontrollable, variables, i t yet seemed desirable t o us t o a t t e m p t t o apply a chemical method of analysis t o a s t u d y of t h e problem. T h e present paper is t h e outcome of t h e very superficial survey of t h e field, a t t e m p t e d in order t o find whether t h e work would show a n y promise of success. For this first a t t e m p t it was unnecessary t o t a k e into account eT-erything known of the composition of wood; t o regard wood as a complex consisting of moisture, cellulose, lignocellulose, with smaller quantities of fats, starches, acid. tannins, etc., was sufficient for t h e purpose I n adopting a method of analysis t h e following considerations h a d weight: I---The decrease in cellulose content should be determined directly b y such a method as t h e chlorination process of Cross a n d Bevan. 11-Inasmuch as decay is associated with increasing molecular simplification, t h e solubility of t h e material should prove worthy of determination. For this reason t h e amounts extracted both b y cold a n d b y hot water were determined. Quite evidently t h e first of these could hardly be reliable because with increasing solubility in cold water there would be an increasing tendency towards loss b y leaching out. 111-The lignin complex gives a variety of characteristic hydrolysis products. It yields furfurol a n d methyl furfurol with strong hydrochloric acid, methyl iodide with strong hydriodic acid, a n d acetic acid when treated with dilute sulfuric acid. This being so i t should be better for t h e present purpose t o determine each product separately t h a n t o establish t h e amount of lignin present, though t h e latter should form a p a r t of a more exact analysis. T h e reason for preferring a determination of t h e hydrolysis products of lignin was simply t h a t t o do so would make i t perhaps possible t o distinguish between t h e fate of different portions of t h e lignin complex. This hope was realized as will be apparent. IV-During its decay. wood becomes more and more similar t o “humus,” which is itself t h e result of partial vegetable decomposition. H u m u s is largely soluble in alkali anti i t , therefore, seemed desirable t o determine the amount of alkali-soluble material in t h e wood l---In addition t o the above determinations, t h e moisture content was found, in order t o allow t h e calculation of all results t o a moisture-free basis. Also, i t \%as thought advisable t o determine t h e percentage soluble in ether, a n d t h e ash. While t h e methods t o be employed were being discussed. t h e authors were very fortunate in receiving, through t h e courtesy of t h e Director of t h e Forest Products Laboratory a t Madison, Wisconsin, a preliminary outline of a method for &rood analysis, due t o the work of Dr. A. It’. Schorger. This proved almost ideal for t h e purpose of this research and was very largely adopted. T h e method is t o be published in t h e near future and we feel t h a t no discussion of methods should be entered upon in t h e present paper and will. therefore, confine ourselves t o giving enough
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detail t o make clear t h e meaning of t h e analytical results. T h e minutiae will be t a k e n u p , if necessary, a t a d a t e subsequent t o t h e publication of t h e contribution of t h e Forest Products Laboratory. T h e authors wish t o t a k e this occasion t o t h a n k D r . Schorger for his kindness. No a t t e m p t was made t o identify t h e fungi responsible for the decay. I n future work some effort must be made t o do this, because even a superficial examination shows t h a t t h e course of disintegration may be very different under nearly similar conditions. T h e difference is probably due t o a variation in the t y p e of fungi present. T h u s t h e spongy products of extreme decay are sometimes very white and consist of masses of fibers having t h e appearance and properties of cellulose, which is, therefore, t h e last portion of t h e wood t o be attacked. On t h e other hand, the samples analyzed shoKed t h e lignin complex t o be t h e most resistant. Evidently different fungi produce very different cytases E X P E R I ME ? T Ai I.
T h e samples analyzed were three, all Douglas Fir: ( I ) Sound heart wood. ( 2 ) Heart wood softened b y decay t o a n extent which made t h e annular rings rather less distinct t h a n in t h e sound specimen, which had changed t h e color t o a whitish yellow (sound wood is reddish), and had made t h e wood much less resistant t o strain a t right angles t o t h e grain. T h e last may be better characterized b y saying t h a t on chopping t h e wood with t h e grain a clean blow would cause i t t o split readily in perfect pieces, b u t t h a t a less violent stroke would frequently cause pieces 2 in. X 2 in. t o break a t right angles t o t h e grain. T h e sample was t a k e n from a fallen tree whose diameter was about 4 feet a t t h e base. T h e portion t a k e n must have been 1 5 feet from t h e ground when t h e tree was standing. T h e t r u n k was still covered with bark. How long t h e tree h a d been dead, i t was, of course, impossible t o determine. The upper end was in a s t a t e of advanced decay under t h e b a r k , t h e wood being quite spongy. Sample 2 could not have lost very extensively b y leaching of water-soluble breakdown products, because i t was t a k e n from near t h e center of the log which was freshly cut T h e wood was wet b u t sufficiently sound t o protect t h e inside portions from a n y rapid removal of soluble products of decay. (3) Heart wood in t h e last stages, t a k e n from what remained of a standing stump. This sample was porous, dark red-brown in color, and could be crushed readily between t h e fingers. Care was t a k e n t o avoid t h e material excreted b y t h e larvae of wood beetles. PREPARATIOS O F SAmLE-The wood mas reduced t o particles which would pass a io-mesh sieve, and this powder was used for all determinations except t h a t of cellulose. I n the latter case fine sawdust, or its equivalent in particles too large t o pass t h e 40-mesh sieve, was used. Care was taken t o obtain as representative a sample as possible. T h e material for analysis was kept in air-tight containers in order t h a t , with t h e moisture once determined, portions could be weighed out and t h e results calculated on a moisture-free basis.
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TABLE I-PERCENTAGES Sample S o .
Cold Water-Soluble. . , . . Hot Water-Soluble(a) ....
OF ANAL\‘SES (1) Heart Wood I1 Av.
I
ROTT E D D O u G L a s FIR g o O D ( 3 ) Complete Rot C O M P A R I S O N OF R6iSWLTS I I1 Av. Heart Wood Partial Rot Complete Rot 1.16 7.77 65.31 8.47
O F S O U N D . PARTIALLY ROTTED A N D COMPLETELY
I
(2) Partial Rot I1 Av.
.......... .............. ....... Pentosan. . . . . . . . . . . . . . . Methyl Pentosan........ Methoxy Group.. ....... Moisture (40-mesh). . . . . Alkali-Soluble Cellulose. Acid Hydrolysis..
0.1;
2.96 6.06
/.so
9.09 8.97 2.72 0.65
Moisture (sawdust). ..... Ether Extract. Ash ( a ) Percentages for “
.........
................... the Total. less the “Cold Water-Soluble.”
A K A L Y T I C.4 L JI E T H OD S
MOISTURE-3
.
Vol. 9 . S o . 3
t o 4 g. dried a t
C. for 6 hours. C O L D W A T E R EXTRACTIOS-2 t o 3 g. digested with 300 cc. cold water for 4 8 hours. n7eight of washed a n d dried residue determined. H O T W A T E R EXTRACTION-2 t o 3 g. extracted with boiling water under reflux for 3 hours. Weight of residue after washing with hot water a n d drying gives loss, from which cold water-soluble is deducted. CELLuLosE-Determined by Cross a n d Bevan’s chlorination method. P E K T O S A N A N D M E T H Y L PEKTOsAN-Determined by t h e Tollen phloroglucide method. A C I D HYDROLYSIS--2 g. t r e a t e d with boiling 2 . j per cent sulfuric acid during 3 hours. T h e volatile acid produced is distilled off a n d titrated. Result calculated as acetic acid. METHoxY-Determined b y Zeisel’s method. E T H E R EXTRACT-3 t o 4 g. extracted i n a Soxhlet a p p a r a t u s for 16 hours. Residue left on evaporation of solvent is weighed. ALKALI-SOLUBLE--P g. are treated with I O O cc. of I per cent N a O H in a boiling water b a t h for one hour. Loss in weight of sample, less percentage removed b y extractions with hot a n d cold water, ether a n d acid hydrolysis, is calculated on moisture-free basis. ASK-5 g. ignited in muffle. T h e results as obtained b y us are probably t o o low, owing t o lack of a suitable muffle. 1 0 j O
D I S C L-S SI 0 S
An examination of t h e results i n Table I makes it evid e n t t h a t t h e composition of wood, as roughly gauged b y t h e inadequate preliminary tests performed, does indeed alter sufficiently during decay t o allow of t h e application of analytical methods of s t u d y The changes taking place are progressive a n d very profound, even in wood which has altered little in struct u r a l appearance. As was foreseen, t h e ether-soluble materials v a r y b u t little. T h e cold water-soluble portion actually decreases regularly, while t h e value for t h e solubility i n hot water increases. T h e tendency towards t h e production of acidic breakdown products is very evident f r o m t h e rapid increase i n alkali-soluble material. T h a t these are formed largely a t t h e expense of t h e cellulose follows from t h e surprisingly rapid fall i n t h e cellulose percentage. Turning t o t h e lignin, t h e evidence is more conflicting b u t also more interesting. I t will be noticed t h a t t w o of t h e lignin values, those for acid hydrolysis a n d pentosan fall, while t w o rise, those for methyl pentosan a n d methoxy, t h e l a t t e r t w o rising a t t h e same
rate, t h u s leaving t h e ratio between t h e m nearly cons t a n t . This result is surprising, a n d highly instructive; it shows t h a t t h e method of inrestigation m a y well throw some light on t h e chemical structure of wood. It is t o o early t o theorize, b u t if a guess m a y be allowed, i t would seem very probable t h a t t h e p a r t of t h e lignin complex which furnishes methyl furfurol, t h a t is, t h e methyl pentosan, also contains t h e methoxy group, a n d t h a t t h e pentosan a n d t h e complex yielding acetic acid on hydrolysis are associated. This is t o be surmised from t h e fact t h a t t h e values for methyl pentosan a n d methoxy show a like ratio throughout a n d also represent a n increasing percentage of t h e whole, t h a t is, appear t o represent t h e most resistant complex in t h e wood. Pentosan a n d t h e hydrolyzable group diminish in percentage progressively though their ratio does not remain constant, a n d i t can only be said t h a t both belong t o a complex or complexes less stable towards decay t h a n t h a t of methyl pentosan a n d met hox y . It should be emphasized t h a t t h e above analyses are merely i n t h e nature of a preliminary a t t a c k . They have served t o show t h e value of t h e method, b u t will need a great deal of amplification. For instance, i t will be necessary t o determine t h e distribution of t h e lignin characteristics between t h e alkali-soluble material a n d t h e residue; direct lignin determinations are required; some a t t e m p t should be made t o isolate products sufficiently pure t o permit of analysis from t h e alkali-soluble substances. Were t h e last t o succeed it would throw much light on t h e vexed question of t h e nature of h u m u s . Another point requiring s t u d y is t h e elementary analysis of t h e wood i n each stage, because t h a t will determine whether t h e changes are accompanied b y oxidation as i t is reasonable t o suppose t h a t t h e y are. Furthermore, t h e gaseous products should be analyzed. I t is hoped t o make these a n d several other questions t h e subject of future papers. SUMMARY
I--Analysis of a sound sample of Douglas Fir heart wood is given. 11-Analyses of a partially a n d of a totally rotten portion of fir are compared with t h a t of t h e original wood. 111-The progress of decay is readily followed by t h e use of chemical methods. Indeed, t h e change is so marked t h a t a comparative cellulose determination might well serve t o detect insipient decay. IT---In t h e cases studied, decay is accompanied b y a 1-ery rapid fall i n cellulose content. \‘-The lignin is f a r more resistant t h a n t h e cellulose. If lignin is a definite compound, t h e n its mole-
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T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERIXG CHEMISTRY
cule does not appear t o decay uniformly, t h e portion first a t t a c k e d being t h a t which yields acetic acid a n d furfurol on hydrolysis. T h e more resistant portion of t h e complex is t h a t which yields methyl furfurol on t r e a t m e n t with concentrated hydrochloric acid, a n d methyl iodide when heated with concentrated hydriodic acid. VI-The results obtained t e n d t o show t h a t t h e method described m a y well be used i n attacking t h e problem of t h e chemical composition of wood a n d of such substances as are found i n humus, i. e., humins, ulmins, huminic, ulminic a n d hymalomelanic acids. VII-Attention is drawn t o desiderata of further work. DEPARTMENT O F CHEMISTRY UNIVERSITYOF WASHINGTON, SEATTLE
THE EFFECT OF EXPOSURE ON COMMERCIAL LIMES By J. CLYDE WHETZEL Received September 22, 1916 INTRODUCTION
The object of this investigation has been t o determine t h e effect of exposure t o t h e atmosphere on t h e carbon dioxide a n d water contents o$ commercial limes, or t h e effect of what is commonly known as “air-slaking” on t h e chemical analysis. It was undertaken t o fix more accurately t h e causes of complaints on high-grade lime shipments a n d t o determine whether these are due t o t h e quality of lime leaving t h e plant or t o deterioration o n t h e road. So far as lime manufacturers are aware, no work has been done on t h i s subject, although it is of importance in t h e lime t r a d e especially i n t h e shipment of high calcium lime for chemical use. M E T H O D A N D E X P E R I M E N T A L DATA
Obviously t h e best way of carrying o u t t h e tests would have been t o expose under t h e exact conditions obtained i n practice, b u t this was not practicable, owing t o t h e expense a n d difficulties of using such large quantities. Accurate sampling is a n i m p o r t a n t factor in t h e analysis of lime shipments a n d is even more troublesome t h a n in t h e case of coal. T h e lime is i n t h e form of large lumps, through which m a y be scattered comparatively large pieces of unburned stone or core, making i t very difficult t o obtain a representative sample unless t h e lime is afterwards ground. I n order t o prevent errors i n sampling, due t o t h e presence of core, t h e lime used in t h e tests was carefully selected b y hand. It was impossible t o use one large sample, quartering a n d sampling a t certain periods, for as t h e lime slaked t h e sampling operations would break i t u p until finally i t would become completely pulverized. This rubbing-off of t h e coating of slaked lime a n d exposure of quicklime would also affect t h e rate of absorption of carbon dioxide and water. T h e containers for t h e bulk lime samples were boxes, having six compartments, 6 in. X 6 in. X 6 in., in each of which was placed a sample. T h e careful selection gave lime sufficiently uniform so t h a t t h e samples were of t h e same composition a t t h e s t a r t , Each box was open a t t h e t o p , b u t a lid was supported a b o u t 6 in. above t h e box i n order t o exclude dust a n d
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dirt. I n order t o compare t h e results obtained by exposure i n boxes with exposure under conditions more closely approaching actual practice, 6 open barrels were filled a b o u t a/4 full of large lumps carefully selected a n d exposed simultaneously. T h e samples of ground a n d hydrated lime were contained i n boxes 6 in. X 6 in. i n cross-section b u t varying i n depth in order t o determine t h e protective effect of t h e upper layers of finely divided material. All the samples were placed for exposure i n a small building a n d were probably i n a more exposed position t h a n would be found in actual practice as t h e building was very loosely constructed a n d i n addition h a d t w o open windows. Several samples were prepared b y quartering from a large pile. One was reserved for analysis a t t h e s t a r t a n d t h e others were placed i n t h e containers, exposed a n d analyzed at t h e intervals indicated i n t h e tables. Available calcium oxide was determined b y t h e direct Solvay method of liberating t h e ammonia from a n ammonium chloride solution a n d titrating with normal hydrochloric acid. Total calcium oxide was determined volumetrically b y precipitation as oxalate a n d titration with s t a n d a r d permanganate. I n determining carbon dioxide, t h e well-known method of absorption in a Geissler bulb was used. Water was found b y difference between loss on ignition a n d carbon dioxide. EXPOSURE O F H I G H CALCIUM LUMP LIhm-This test consisted in t h e determination of t h e r a t e a t which high calcium l u m p lime takes u p carbon dioxide a n d water, T w o sets of samples were exposed simultaneously: one set containing l u m p lime */d in. t o 2 in. i n size a n d placed i n t h e boxes, t h e other 5 in. t o 6 in. in size a n d contained in t h e barrels. T h e analyses a n d other d a t a are given in Tables I a n d 11, t h e latter giving t h e results obtained with t h e barrel samples.
--
TABLE I-HIGH CALCIUMLUMPLIME (BOXES) Per cent Complete Per cent Available Analysis CaO D r y before Exposure posed Avail. T o t a l COa Ha0 Basis 0 95.6 96.2 0.2 1.6 97.2 Si02 0.20% RzOs 0.78 11.6 96.0 7 84.8 86.5 0.8 13.6 93.9 CaO 96.17 83.1 1.0 81.1 15 30 76.2 79.4 1.7 15.5 90.3 1.01 45 68.0 72.0 2.4 21.4 86.6 0.16 60 64.7 70.3 3.1 22.7 83.6 HtO 1.56 TABLE 11-BARRELS Si02 0.56yc 1.7 96.7 0 94.9 95.4 0.2 RaOa 0.80 7 87.7 88.9 0.7 9.3 96.6 CaO 95.38 1 0 10.4 94.9 15 85 1 87 1 30 82:4 83:s 1:l 12.7 94.3 1.15 0.24 1.2 14.6 94.6 45 81 0 82.5 60 73:O 75.1 1.8 19.4 90.8 Hg0 1.74 TABLE111-MAGNESIEM LUMP LIME (BOXES) 0 ’. 0.3 3.2 .. Si02 0.21% 7 , 1.2 8.8 .. RzOs 0.66 .. .. 1.8 11.3 . CaO 56.64 15 30 .. 1.9 13.5 . MgO 38.89 ., 1.9 15.5 . coz 0.33 45 .. 60 ,. 2.6 15.6 Ha0 3.17 TABLE IV-HIGH CALCIUMLUMPLIME 0.907, 94.5 0.3 0.5 95.0 0 96.3 0.87 7 0.6 3.9 94.9 90.2 93.8 84. i 96.27 i.6 88.8 14 1.5 91.6 87.6 0.94 85.0 9.4 21 0.9 93.8 86. i 10.3 0.25 1.5 91.9 82.4 28 0.51 84.2 80.i 12.7 1.6 92.4 35 TABLE V-HIGH CALCIUMHYDRATED LIME 1.01% 27.3 . . Si02 0 .. .. 1.1 RzOa 1.40 25.2 .. 20 .. .. 1.4 CaO 68.05 20 . 2.3 24.6 . 1.31 20 .. ,. 5.6 23.7 ,. 1.05 Hz0 2i.25 TABLE VI-HIGH CALCIUMGROUNDLIME (10 MESH) .. .. 1.7 6.2 Si02 1.64% 0 .. ,, 2.5 12.2 .. RzO: 2.38 20 _. .. 2.9 14.4 . CaO 85.48 20 .. . . 4 . 0 18.4 .. 20
Date Analyzed (1915) 6/17 6/24 7/2 7/17 :$;6 6/17 6/24 :$:7
:4;6 6/17 6/24
$:7: 8/1 8/16 2/13 2/20 2/27 :g3 3/20 7/27 8/16 8/16 8/16
7/27 8/16 8/16 8, 16
Days
Ex-
Per cent
%?
25:
.
.. ..
..
..
. ..
..
..
.
.
.. .
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2 6 :
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6.19
