. ■ 
 
 a i* 
 
 THE BONDING EORCE €f CELLLLCSIC MATERIALS 
 EOR WATER (FROM SPECIFIC VOLUME 
 AND THERMAL DATA) 
 October 1937 
 
 SCHOOL Of FORESTRY 
 
 HOT OF FLORIDA 
 
 HUM 
 
 UNITED STATES DEPARTMENT OF AGRICULTURE 
 
 FOREST SERVICE 
 
 FOREST PRODUCTS LABORATORY 
 
 Madison, Wisconsin 
 
 In Cooperation with the University of Wisconsin 
 
 
THE BOITDIHG FORCE OF CELLULOSIC MATERIALS FOR !v r ATER 
 (FROM SPECIFIC VOLUME AID THERMAL DATA)1 
 
 By A. J. STAMIi 
 and L. A. HAIT3SI7 
 
 An attempt was made in a previously reported research (lU) to 
 determine the volumetric contraction occurring in the water adsorbed "by 
 cellulosic materials. Apparent density measurements of wood and cellulose 
 containing various amounts of adsorbed water were made in "benzene. Ben- 
 zene causes no swelling of cellulosic materials', indicating that its 
 affinity for cellulosic materials is small. This, together with the 
 fact that the internal surface of contact is relatively small, would 
 make the adsorption compression of benzene negligible. It is question- 
 able, however, that benzene penetrates the void structure of the dry 
 cell walls completely. For this reason the benzene can be relied upon 
 as a displacing medium only when the moisture content of the cellulosic 
 material is sufficiently high for water to have opened up or itself 
 filled all of the void structure. It was shown that the volumetric con- 
 traction occurring in the adsorbed water could be calculated down to a 
 moisture content of about 6 percent from the measurements in benzene. 
 Below this point accurate data for the true density of the cellulosic 
 materials are required to make the calculations. 
 
 Howard and Hulett (6) have determined the density of carbon in 
 helium and have shown that at room temperatures the helium is practically 
 nonadsorbed. Davidson (3) similarly concluded that helium is nonadsorbed 
 on cellulose. Because of its low molecular weight it should further 
 penetrate the void structure completely. Hence, measurements of the 
 density of the same cellulosic materials used in the previous investiga- 
 tion were made in helium. 
 
 The essential features of the apparatus used for making the density 
 measurements are shown in figure 1. A and B are two Pyrex glass bulbs of 
 about 200-cc. capacity, separated by a stopcock S-j_. The sample bulb A 
 can be removed at the ground-glass joint J and f Tiled with the cellulosic 
 material by removing the stopcock. S-, , So, and J are provided with mer- 
 cury seals to prevent leaks. M is a"~mercury manometer, which was read 
 with a cathetometer to 0.005 cm « L is a 200-cc. bulb used to keep the 
 mercury level in the right-hand arm of M at the same point for all the 
 
 —Presented at the l^th Colloid Symposium, Minneapolis, Minn., June 10-12, 
 1937 • Published in the Journal of Physical Chemistry, Vol. ^1, Ho. 7, 
 Oct. 1937. 
 
 RI23U 
 
measurements "by adjusting the pressure ever L with stopcocks S3 and SU. 
 This made unnecessary any volume corrections. The whole apparatus was 
 immersed in a thermostatically controlled water "bath at 3^° "• + 0.01°. 
 
 The volume of A was determined by calibration with I r. With 
 A empty the apparatus was completely evacuated, helium was admitted to 
 B, the pressure determined, and then the pressure was again determined 
 after expansion into A. The volume of 3 plus the connecting tubes could 
 then be calculated from the volume of A and the two pressures, using the 
 perfect gas law. The same procedure was followed in determining the vc I 
 space in A when filled with a sample of wood or cellulose. The material 
 was oven-dried at 105° C. prior to filling the bulb and then vacuum- 
 dried, at 105° C. for about 2- hours after assembly of the apparatus 
 by surrounding' the bulb with a heating coil jacket. A final vacuum of 
 about 10" mm. of mercury was- attained. The system was then brought to 
 30° C. and held for about half a day before making the measurements, to 
 insure thermal equilibrium. Weighings of. the sample bulb were made at 
 atmospheric pressure just after the vacuum drying and again after a series 
 of expansions. 
 
 Density measurements were also made in water and benzene in 200-cc. 
 plate-top pyenometers. The air was removed from the submerged ..-.aterials 
 in the half -filled pyenometers by carefully applying a vacuum and releas- 
 ing until no sign of air bubbles was obtained up to a vacuum which cause 
 boiling of the liquid when the pyenometers were immersed ir. an ice ba1 . 
 
 The densities of the following materials determine! in helium, 
 water, and benzene, are given in table 1: benzene-alcohol extracted 
 spruce sawdust of Uo to oO mesh; the same in the expanded aerogel form 
 (8); standard cotton linters alpha-cellulose; a normal spruce sulfite 
 pulp and the same after beating for 20 hours; and spruce and ma 
 lignin prepared by the modified sulfuric acid method of the Jcrest 
 Products Laboratory (l_l) . The expanded aerogel was prepared accordir. 
 to the method of Kistler (_3) , using methanol and acetone as intermedi 
 replacing agents. Measurements on control blocks showed that a large 
 proportion of the normal shrinkage occurred in the final expansion step, 
 regardless of the technic used. Because of this shrinkage the densi: 
 value for the expanded wood determined in benzene, although greater than 
 the corresponding density value for the unexpanded wood, was not so great 
 as the density value determined in helium. In all cases the densi": 
 values determined in helium are intermediate between those determined 
 in water and those determined in benzene, as has been previously 
 reported (^, 12) . The difference between the helium and benzene values 
 for the cotton is practically the same as that found by Davidson ( 
 
 R123U -2- 
 
n 
 
 Table 1. — Densities of wood, cellulose, and lignin substance at 30° C 
 
 Substance 
 
 Extracted white 
 spruce 
 
 Expanded aerogel 
 from extracted 
 white spruce. 
 
 Standard cotton 
 linters , 
 
 Spruce sulfite 
 pulp: 
 
 Unbeaten 
 
 Beaten 
 
 Spruce lignin 
 (modified sulfur- 
 ic acid method) . , 
 
 Maple lignin 
 (modified sulfur- 
 ic acid method) . , 
 
 :Helium 
 
 displacement 
 
 : Water 
 
 displacement : 
 
 : Den- 
 : sity 
 
 : Aver- 
 : age 
 : error 
 
 : Num- 
 :ber of 
 • deter- 
 mina- 
 tions 
 
 : Den- 
 : sity 
 
 : Aver- 
 : age 
 . error 
 
 : Hum- : 
 :ber of: 
 
 deter-: 
 : mina- : 
 
 tions : 
 
 :1.U603 
 
 G.0005 
 
 10 
 
 1.5332 
 
 0.0002 
 
 2 : 
 
 :l.U6oH. 
 
 .oooU 
 
 k 
 
 1.530 
 
 
 1 : 
 
 :1.5S5 
 
 .0012: 
 
 7 
 
 1.602? 
 
 .0003 
 
 2 : 
 
 : 1.570 : 
 :1.593 i 
 
 .002^, 
 .0022: 
 
 6 
 
 b 
 
 1.590 
 I.616 
 
 .0005 
 .0008 
 
 2 : 
 
 2 : 
 
 ji-377 : 
 
 .0003: 
 
 10 
 
 1.399 
 
 .0010 
 
 2 : 
 
 • 
 
 :1.U06 ! 
 
 .0011: 
 
 6 
 
 1.U22 
 
 l 
 .0007 
 
 * 
 
 : 
 
 2 : 
 
 • 
 
 Benzene displacement 
 
 Den- 
 sity 
 
 lMk 
 
 I.U50 
 
 1.571 
 
 1.555 
 1.57S 
 
 1I.366 
 
 Aver- 
 age 
 
 error 
 
 0.007 
 
 .005 
 
 .0005 
 
 Num- 
 ber of 
 deter- 
 mina- 
 tions 
 
 The volume contraction occurring in the cellulosic material- 
 adsorbed water system was calculated from the previously determined data 
 in benezene (lk) , using the newly found density values in helium as the 
 true densities of the cellulosic materials. The external pressure P in 
 kilobars that would be required to cause this volume change Av P er gram 
 of water, on the basis of the volume change occurring entirefy~in the 
 water phase, was then calculated from the following compressibility 
 relationship for water given by Gibson (5): 
 
 Av = 0.307 log 2 '9 2 3 + P 
 2.923 
 
 (1) 
 
 The values for white spruce, cotton, and sulfite pulp are plotted in 
 figure 2. The values for the beaten and the unbeaten pulp were so nearly 
 identical that only the average value is plotted. 
 
 R123U 
 
 •3- 
 
7 
 
 Campbell and Russell (2) have doubted whether helium completely 
 penetrates the void structure of cellulose, because they obtained density 
 values for swollen cellulose in benzene by replacement of water with al- 
 cohol and of alcohol with the benzene that were slightly greater than the 
 helium values. This difference, it seems, can be better explained by 
 assuming that a small amount cf water was net replaced in their measure- 
 ments, rather than by assuming that the helium fails to penetrate the 
 cellulose completely. In order to meet these investigator's objections, 
 however, it seemed advisable to attempt determining the compression 
 effect by an entirely different method. 
 
 Katz (j) has shown that a qualitative proportionality exists between 
 the initial heat of solution or the heat of swelling of binary aqueous 
 systems and the accompanying volume change. Ee gives values for the ratio 
 ^o/"o ran S in 6 from 1 to 3 x 10~3 for a series of solutions and swelling 
 systems in which C is the volume change in cubic centimeters and H is 
 the heat of solution or swelling in gram-calories resulting when 1 g. of 
 water is added to an infinite amount of dry solute or swelling material. 
 It is apparent that this relationship cannot be general, as there should 
 be a greater change in volume per unit thermal change for a more compres- 
 sible liquid than for a less compressible liquid. It thus seemed logical 
 to substitute the change in internal pressure ? e , which causes the change 
 in volume, for the change in volume and thus compare values of the differen- 
 tial ratio P e /H. Partial differential values are used, as compress! 
 may occur in both constituents of the liquid-liquid systems considered. 
 
 G-ibson (_£) gives the relationship between the specific compression 
 of water, the internal or intrinsic pressure change, and the externally 
 applied pressure which can be expressed in the following partial differen- 
 tial form: 
 
 - ££Z = o.3D7 log 2.923 + ?e + ? (2) 
 
 *1 2.923 + p e 
 
 where _APZ represents the partial comoression of the water ^>er gram of 
 
 x l 
 water resulting from the partial internal pressure change of the water 
 P e in kilobars caused by the presence of the solute and the external 
 
 pressure change P in kilobars. The partial specific compression can be 
 obtained by plotting the compression per gram of solution against the 
 weight fraction of the water and drawing tangents to the curve. Z 
 intercept of the water axis gives the partial specific compression for 
 water in a solution the composition of which is represented by the point 
 of tangency (9) • 
 
 The external pressure P that would cause the same volume change in 
 the solvent as occurs in the process of solution qvj\ ^e calculated from 
 equation 1 expressed in a partial form: 
 
 Vl _ v x = 0.307 log 2u l 2 l+ P (3) 
 
 RI23U -h- 
 
in which v-l is the specific volume of the water and v-^ is the partial 
 
 specific volume of the water in the system, obtainable in a similar way 
 to the partial specific compression. 
 
 Gibson (^) gives data for both the specific volume and the compres- 
 sibility of a sulfuric acid-water system. From these data the external 
 pressure required to give the partial specific volume change of the 
 water can be calculated, using equation 3» an d the change in the inter- 
 nal pressure that causes the change in compressibility can be calculated, 
 using equation 2. These values are given in table 2. The data show that 
 the internal pressure change of water in the solutions is equal to the 
 external pressure required to cause an equal change in volume in the 
 water alone. It is thus valid to consider the pressure changes in 
 figure 2 equivalent to internal pressure changes. 
 
 Table 2. — Change in nartial internal pressure of water in aqueous 
 s ulfuric acid solutions calculated from the specific 
 volumes and from the specific compressions 
 
 
 Weight 
 
 Specific volume 
 
 External 
 
 Partial specific 
 
 Change in 
 
 Solute 
 
 fraction 
 
 minus partial 
 
 pressure on 
 
 compression of 
 
 loartial 
 
 
 of 
 
 specific volume 
 
 HgO to give 
 
 HgO per kilo- 
 
 internal 
 
 
 H 2 
 
 of HpO 
 
 volume change 
 
 bar 
 
 pressure 
 
 : of H 2 
 
 
 ( Xl ) 
 
 (v x - vp 
 
 (P) 
 
 v x l ' 
 
 (Pe> 
 
 
 
 
 Kilobars 
 
 
 Kilobars 
 
 h 2 so h 
 
 0.0 
 
 0.308 
 
 26. 8 
 
 o.ooHs 
 
 : 26.0 
 
 .0723 
 
 .1365 
 . .2167 
 : . U0U8 
 
 .6699 
 
 .283 
 .193 
 •093 
 .038 
 .012 
 
 21.3 
 
 9.3 
 3.0 
 
 •95 
 .28 
 
 .0055 
 
 .0110 
 
 .0225 
 .0312 
 
 .0367 : 
 
 21.0 
 
 g.7 
 
 2.5 
 .25 
 .25 
 
 
 ■ -7333 
 .873U 
 
 .008 
 
 .ooh 
 
 •17 
 .08 
 
 .0380 
 .0390 
 
 : .13 
 : .Oh 
 
 Table 3 gives the ratios of the partial internal pressure change to 
 the partial heat of solution of water in aqueous solutions of organic 
 compounds, inorganic acids, bases, and salts, and salts of organic acids 
 all of which dissolve with the evolution of heat. The partial internal 
 pressure changes were calculated from specific volume data only ( Inter - 
 national Critical Tables ), as specific compression data wore available 
 only for the sulfuric acid solutions. The heat of solution data, with 
 the exception of that for sulfuric acid (10) were also obtained from the 
 International Critical Tables . Because of the difficulty of obtaining 
 accurate graphical values for v-^ and for E at high concentrations of 
 
 RI23U 
 
 -5- 
 
7 
 
 water, the values for the ratio P c /E could not be determined at concentra- 
 tions higher than those given in table 3 with any degree of accuracy. In 
 all oases where miscibility is complete, the ratios of P e /H for zero con- 
 centration of water are about equal, the average deviation from the 
 average value 12.5 being *4 percent. The same constancy exists for all 
 the data at high concentrations of water* In some cases the agreement 
 is good over the whole concentration range, whereas in other cases, si 
 as that of sulfuric acid, the ratio decreases at intermediate concentra- 
 tions* In the case of the salts and bases the agreement is good up to 
 concentrations approaching saturation. 
 
 This relationship fails to hold for exothermic solutions* Tnu ex- 
 pansion accompanying the absorption of heat is invariably too small, and 
 in some cases there is a slight contraction accompanying the absorption 
 of heat. The relationship also fails in cases where the constituent 
 other than water is more compressible than water. As neither of these 
 cases a;oplies_jto cellulose-water systems, it seemed justifiable to apply 
 the ratio P e /H = 12.5 kilobars per kilo joule in the calculation of P @ 
 
 from thermal data. Values of P e for the wood ana cotton calculated from 
 
 the heat of swelling data (3/5) that were obtained from vapor pressure 
 data (r3, 15) and from direct heat of sv;elling data (l) are plotted in 
 figure 2, together with the values of P obtained from adsorption compres- 
 sion. The agreement is good. It tends to substantiate the contention 
 that true density values for cellulosic materials can be obtained in 
 helium and strengthens the validity of the calculated internal pressure 
 values. 
 
 The values of P e represent the increase in the internal pressure of 
 
 water, so that the normal internal pressure of water, which is about 
 12.5 kilobars, should be added to ther,e values to obtain the total inter- 
 nal pressure. The data thus show that the initial bonding force of 
 cellulosic materials for water is about twice that of water for itself. 
 This seems much more reasonable than the value of sevenfold to eightfold 
 greater calculated from the data of Filby and Maass (U-) , especially i n 
 the light of the fact that the initial attractive force of sulfuric 
 acid for water is only three times that of water for water (see table 3) • 
 It i3 of interest to note that the surface-bound water corresponding to 
 the inflection point of the moisture content-relative vapor pressure 
 curves, 5 to 6 percent for wood and about 3 percent for cotton, exhibits 
 the came internal pressure of about 22.5 kilobars for bc r >d and 
 cotton. The average force with which all the water is held below the 
 fiber-saturation point varies for the different cellulosic materials; 
 15.5 kilobars for the wood, 14. 7 for the cotton, and 13.5 for the pulp, 
 or 24, 17, and 8 percent greater than the force wit Lch water holds 
 wat er . 
 
 R1234 -6- 
 
Table 3* — Relationship "between the change in the partial internal pres - 
 sure of water and the partial heat of solution of water in 
 the formation of various aqueous solutions 
 
 
 : Weight 
 
 : Specific 
 
 : Changes in par - 
 
 : Partial heat 
 
 
 Solute 
 
 : fraction 
 
 : volume minus 
 
 : tial internal 
 
 : of solution 
 
 : Ratio 
 
 
 : of H P 
 
 : partial 
 : specific 
 : volume of 
 : H 2 
 
 : pressure of 
 
 : n 2 o 
 
 : of H 2 
 
 p 
 
 
 ; (-i> 
 
 (▼l - ▼]_) 
 
 ; (p) 
 
 : (5) 
 
 
 
 0.0 
 
 0.0U0 
 
 : Kilohars 
 : 1.00 
 
 Kilo.ioailes 
 
 
 
 C.081 
 
 : 12.3 
 
 
 .1 
 
 .028 
 
 .69 : 
 
 .056 
 
 : 12.3 
 
 
 p 
 
 .023 
 
 ! .55 
 
 .0U3 
 
 : 12.8 
 
 Glycerol/ 
 
 •3 
 
 .019 
 .012 
 
 .28 
 
 .037 
 .027 
 
 : 12.2 
 : 10. k 
 
 
 •5 ■ 
 
 . 010 
 
 .22 
 
 .021 
 
 : 10.5 
 
 
 r 
 
 . : 
 
 .0075 
 
 : .16 : 
 
 .01 k 
 
 11. U 
 
 
 • 7 = 
 
 .00^ 
 
 .09 
 
 .008 
 
 11.2 
 
 
 .0 : 
 
 .053 
 
 l.*K) 
 
 .100 
 
 l k .0 
 
 
 .1 : 
 
 .OUh 
 
 1.15 : 
 
 .0365 
 
 13.3 
 
 
 .2 : 
 
 •035 
 
 .S^ : 
 
 .065 
 
 : 13.5 
 
 
 :l ; 
 
 .026 
 
 .63 
 
 ,0^9 
 
 12.9 
 
 Glycol.. (: 
 
 .019 : 
 
 .U5 
 
 .0375 
 
 12.0 
 
 
 • 5 : 
 
 .OlU 
 
 .325 : 
 
 .029 
 
 11.2 
 
 
 .6 : 
 
 .009 : 
 
 .20 : 
 
 .022 
 
 9.1 
 
 
 • 7 : 
 
 .005 : 
 
 .11 : 
 
 .0125 
 
 8.8 
 
 
 .8 : 
 
 .002 : 
 
 .0^5 : 
 
 .0035 
 
 12.8 
 
 
 .0 : 
 
 .198 
 
 10.2 : 
 
 •90 
 
 11.3 
 
 
 .1 : 
 
 .190 : 
 
 9.3 : 
 
 . 80 
 
 11.6 
 
 
 .2 : 
 
 .163 : 
 
 7.0 : 
 
 •55 : 
 
 11.8 
 
 HMO7. . .. j\ 
 
 •3 : 
 
 .136 : 
 
 5.0 : 
 
 •39 
 
 12.8 
 
 
 .U : 
 
 .086 : 
 
 2.7 : 
 
 .22 
 
 : 12.0 
 
 
 •5 : 
 
 .058 : 
 
 1.6 : 
 
 .13 : 
 
 12.3 
 
 
 .6 : 
 
 .036 : 
 
 • 9 : 
 
 .08 : 
 
 11.2 
 
 
 •7 : 
 
 .011 : 
 
 .25 : 
 
 .02 : 
 
 12.5 
 
 (continued on next page) 
 
 R123U 
 
Digitized by the Internet Archive 
 
 in 2013 
 
 http://archive.org/details/bondinOOfore 
 
Table 3* — Continued. 
 
 
 
 : Weight 
 
 : Specific 
 
 ! Changes in par- 
 
 Partial heat 
 
 
 Solute 
 
 : frac- 
 
 : volume minus 
 
 it ial internal 
 
 1 of solution 
 
 : Ratio 
 
 
 : tion 
 
 : partial 
 
 pressure of 
 
 of H 2 
 
 
 
 of H o 
 
 : specific 
 
 E-,0 
 
 
 
 
 C. 
 
 volume of 
 H ? 
 
 Cm 
 
 
 : f ? l 
 
 
 ! (^) 
 
 (v x - TjO 
 
 ! (p) 
 
 (I) 
 
 ; c s ) 
 
 
 0.0 
 
 0.129 
 
 Eilobars 
 
 4.80 
 
 Kilojoiiles 
 
 
 
 0.1+3 
 
 : 11.2 
 
 
 .1 
 
 .093 
 
 3.00 
 
 .37 
 
 : S.l 
 
 
 .2 
 
 .06s 
 
 1.95 
 
 .25 
 
 : 7-8 
 
 
 .3 
 
 .03s 
 
 1.00 
 
 .11+ 
 
 : 7-1 
 
 H^POu. ../ 
 
 .4 
 
 .028 
 
 .70 
 
 .08 
 
 : 8.7 
 
 
 • 5 
 
 .021 
 
 .50 
 
 .05 
 
 10.0 
 
 
 .6 
 
 .010 
 
 .23 
 
 .02 
 
 11.5 
 
 
 • 7 : 
 
 .006 
 
 .13 
 
 .015 : 
 
 11.5 
 
 
 .0 
 
 .306 
 
 26.5 : 
 
 1.92 
 
 ! 13.8 
 
 
 .05 - 
 
 .292 
 
 23.O : 
 
 1-75 
 
 : -13.1 
 
 
 .10 : 
 
 .260 
 
 17.5 
 
 1.50 
 
 11.7 
 
 
 .15 : 
 
 .182 
 
 8.5 
 
 1.12 
 
 : 7.6 
 
 
 .20 ' 
 
 .106 
 
 3.6 
 
 •73 
 
 4.6 
 
 K 2 S0^. ..,', 
 
 .30 : 
 
 .052 : 
 
 1.4 
 
 ^3 
 
 3.3 
 
 .40 : 
 
 .0355 
 
 .92 : 
 
 .26 
 
 • 3*5 
 
 
 .50 . 
 
 .0265 
 
 .6H 
 
 .11+ 
 
 : 4.6 
 
 
 .60 : 
 
 .0176 
 
 .1+0 : 
 
 .08 : 
 
 5.0 
 
 
 .70 : 
 
 .0095 
 
 .22 
 
 .01+ 
 
 5.5 
 
 
 .SO : 
 
 .004^ 
 
 .10 
 
 .015 
 
 . 6.7 
 
 
 .90 : 
 
 .0025 
 
 .05 
 
 .004 
 
 : 12.5 
 
 
 .425 ' 
 
 .115 
 
 4.00 
 
 .420 
 
 : 9.5 
 
 
 • 5 : 
 
 .083 
 
 2.57 
 
 .255 
 
 : 10.1 
 
 KOH. . .(: 
 
 . b ! 
 
 .0^5 
 
 1.20 : 
 
 .110 
 
 : 10.9 
 
 
 •7 s 
 
 .01U 
 
 • 33 
 
 .027 
 
 : 12.2 
 
 
 .3 : 
 
 .0075 
 
 .17 
 
 .014 
 
 : 12.1 
 
 
 .6 \ 
 
 .ioH 
 
 3.50 
 
 .295 
 
 11.9 
 
 ITaOH ( 
 
 •7 
 
 .068 
 
 1.95 
 
 .i4o 
 
 13.9 
 
 
 .8 
 
 .023 
 
 .55 
 
 .o4o 
 
 : 13.7 
 
 (continued on next page) 
 
 R1234 
 

Table 3« — Continued. 
 
 
 Weight 
 
 Specific 
 
 Changes in par- 
 
 Partial heat 
 
 
 Solute 
 
 frac- 
 
 volume minus 
 
 tial internal 
 
 of solution 
 
 Hat i 
 
 
 tion 
 
 partial 
 
 pressure of 
 
 of 
 
 
 
 of 
 
 specific 
 
 H 2 
 
 H 2 
 
 
 
 H 2 
 
 volume of 
 H 2 
 
 
 
 (1) 
 
 
 (x x ) 
 
 (v 1 - v x ) 
 
 (P) 
 
 (H) 
 
 
 
 
 Kilobars 
 
 Kilojoules 
 
 
 
 0.1+ 
 
 0.03S 
 
 0.97 : 
 
 0.075 : 
 
 12.9 
 
 
 .5 
 
 .027 : 
 
 .66 
 
 .053 ' 
 
 12.1+ 
 
 KCpii-zOo • / 
 
 . .6 : 
 
 .018 
 
 .^3 
 
 .035 
 
 12.3 
 
 • 7 
 
 .008 
 
 .175 
 
 .013 
 
 13.5 
 
 
 .8 
 
 .0015 
 
 .032 
 
 .0022 
 
 11+.5 
 
 
 • 9 
 
 .0005 
 
 .013 
 
 .001 
 
 : 13.O 
 
 
 • 7 
 
 .00b : 
 
 .13 
 
 .010 
 
 : 13.0 
 
 HaC 2 E-z0 2 ( 
 
 
 .002 
 
 .0^5 
 
 .0035 
 
 12.3 
 
 -9 
 
 .0005 
 
 .013 
 
 .001 
 
 13.0 
 
 
 .6 
 
 .okk 
 
 1.15 
 
 .O96 
 
 : 12.0 
 
 CaCl 2 . . .( 
 
 • 7 
 
 .020 
 
 .1+8 
 
 .038 
 
 12.6 
 
 
 • O 
 
 .00Q 
 
 .20 
 
 : .015 
 
 : 13.3 
 
 MgCl 2 . . ./ 
 
 •7 
 .8 
 
 .032 
 .012 
 
 .80 
 .28 
 
 .070 
 .025 
 
 11. u 
 
 11.2 
 
 
 .U 
 
 .052 
 
 1.1+ 
 
 : .130 
 
 : 10.8 
 
 
 • 5 
 
 .035 
 
 1.0 
 
 .087 
 
 : 11.5 
 
 ZnCl 2 . . . j 
 
 .6 
 
 .02U 
 
 .58 
 
 : ,0l+8 
 
 12.1 
 
 .7 
 
 .017 
 
 .1+0 
 
 : .033 
 
 : 12.1 
 
 
 .8 
 
 . 009 
 
 .20 
 
 : .018 
 
 : ll.l 
 
 
 • -9 
 
 .004 
 
 .0Q 
 
 .008 
 
 11.2 
 
 
 ■ .7 
 
 .01H 
 
 • 33 
 
 ! .095 
 
 '' 3.6 
 
 LiCl ( 
 
 : .S 
 
 .005 
 
 .20 
 
 : .018 
 
 : 12.0 
 
 
 : -9 
 
 .00U 
 
 • 09 
 
 : .007 
 
 12.8 
 
 
 ! .6 
 
 .032 
 
 .80 
 
 : .055 
 
 ; 11+.5 
 
 CuCl 2 . . . ( 
 
 : .7 
 
 : .022 
 
 •52 
 
 : .036 
 
 : 11+.1+ 
 
 
 : .8 
 
 .005 
 
 : .20 
 
 : .016 
 
 : 12.5 
 
 (Table 3 concluded) 
 
 RI23I+ 
 
REFERENCES 
 
 (1) Argue, G. K. , and Maass, 0.: Can. J. Research 12, 56U (1935) ■ 
 
 (2) Campbell, V. G. , and Russell, J. E. : Quart. Rev. Forest 
 
 Products Lab. (Canada), Jan. -Mar., p. 24 (1935). 
 
 (3) Davidson, G. F.: J. Textile Inst. 12, T175 (1927). 
 
 (4) Filby, E. A., and Maass, 0.: Can. J. Research 7, l62 (1932). 
 
 (5) Gibson, R. E. : J. Am. Chem. Soc. 56, k (1934); 57- 234, 1551 (1935). 
 
 (6) Howard, H. C. , and Hulett, G. A. : J. Phys. Chem. 2S, 10S2 (1924). 
 
 (7) Eatz, J. R. : Eoninkl. Akad. Wet ens chapmen Amsterdam, Proc. Sec. 
 
 Sci. 13, 975 (1910) (in English) ; "Trans. Faraday Soc. 29, 279 
 
 (1933). 
 
 (8) Eistler, S. S.: J. Phys. Chem. 36, 52 (1932). 
 
 (9) Lewis, G. IT., and Randall, M. : Thermodynamics, p. 32. The McGraw- 
 
 Hill 3ook Co., New York (1932). 
 
 (10) Marschall, A. L. : in E. S. Taylor's Treatise on Physical Chemistry, 
 
 1st edition, Vol, I, p. 217, D. Van Nostrand Co., New York 
 (1924). 
 
 (11) Sherrard, S. C. , and Harris, E. E. : Ind. Eng. Chem. 24, 103 
 
 (1932). 
 
 (12) Stamm, A. J.: J. Phys. Chem. 33, 398 (1929). 
 
 (13) Stamm, A. J., and Loughborough, V. E. : J. Phys. Chem. 39, 121 (1935). 
 
 (14) Stamm, A. J., and Seborg, R. H. : J. Phys. Chen. 39, 133 (1935). 
 
 (15) Urquart, A. R. , and Williams, A. H. : J. Textile Inst. 15, T559 
 
 (1924). 
 
 R1234 -7- 
 

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