BULLETIN OF THE BUSSEY INSTITUTION. 415 
soda lye. He obtained less than 0.8% from spruce wood and less 
than 0.5% from fir wood, and half of this quantity was ashes. 
*¢ In these coniferous trees,” he says, ‘* wood-gum appears to be 
absent or at the least to be present in very minute quantities.” 
Koch* in his turn says :— No wood-gum can be got from the wood 
of coniferous trees or from vegetable tissues that are free from 
lignin. The small quantities of this substance which appear to be 
got from coniferous trees and from some tissues by means of soda 
lye may be regarded as products of the decomposition of cellulose. 
On macerating pure cellulose with 10% soda lye almost half its 
weight goes into solution in the form of a soda-compound, of the 
composition 4C,H,,O; + NaHO, which separates out on adding 
alcohol. : 
Wheeler and Tollens + got ‘‘ very small quantities of wood-gum 
from fir wood,” 7. e. no more than 0.4%, though they found that 
the wood itself yielded xylose on hydrolysis. From jute they got 
1.73% of wood-gum, and they obtained xylose also by hydrolyzing 
the jute itself. 
Hoffmeister { soaked powdered pine and fir wood in ammonia 
water (after Thomsen) and in other instances he boiled the woods 
in water, and then treated them with 5% soda lye. But, as he 
says, next to nothing went into solution in the soda; even stronger 
soda lye up to 20% dissolved nothing, 7. e. at the ordinary tempera- 
ture of the air. 
Tauss § in his elaborate experiments on the behavior of woods 
and cellulose, when treated with soda lye at high temperatures, 
found that fir wood on being boiled for three hours, under the 
ordinary atmospheric pressure, in three successive portions of 
sod. lye of 1.043 sp. gr. (8% NaHO), dissolved to the extent 
of 28% of the air dried wood, but that alcohol precipitated nothing 
from this solution, while acid precipitated 1.31% of the air dried 
wood. 
Fir wood similarly treated with lye of 1.09 sp. gr. (8% NaHO) 
dissolved to the extent of 49% its weight, but only some traces of 
* Berichte der deutschen chemischen Gesellschaft. 20. (Ref.) p. 145. 
+ Berichte der deutschen chemischen Gesellschaft. 22. 1046; Annalen 
der Chemie und Pharmacie. 254. 324. 
t Landwirthschaftliche Jahrbiicher. 1888, 17, 259; 1889, 18. 772. 
§ Dingler’s Polytechnisches Journal. 1890, 276. 418. 
