BULLETIN OF THE BUSSEY INSTITUTION. 393 
during one hour with hydrochloric acid of 1%, according to 
Stone’s * suggestion, and the sugar thus formed was estimated with 
copper and calculated from Allihn’s table, as before, there were 
obtained the results which are set forth in the following table : — 
Pentosans obtained with Acid of One per cent. 
Kind of Wood. Per cent of pentosans (wood dry at 100° C.). 
Inner Wood. Outer Wood. Bark. 
Gray Birch felled in May .... . 12.49 11.41 (I.) 12.42 
oss - Be Se ee rms ries Og in (II.) 12.21 
“ Me I) vce wy en! 9.88 11.20 12.32 
6 73 , e 5 
A, ; a | October (I.) 11.60 12.05 \ 15.06 
se seg ail “ (II.) 12.01 12.01 
Se a BB 
Peach sia eee ye oes eee ae 
SURE Ge es 021.78 (Paramannan). 
ES Le ener FS Pe Ss) v6 
On comparing these results, as obtained with woods, with those 
stated previously in the table on page 392, which were obtained 
by boiling the woods during three hours in hydrochloric acid of 
about 2.5%, it will be seen that the quantities of xylan hydrolized 
in the two cases are in some measure proportionate to the strength 
of the acid employed and to the length of time during which the 
acid is made to act. Indeed, on subtracting from the figures ob- 
tained by the use of 1% acid, the quantities of ‘‘ starch,” as 
determined by means of diastase, it will be perceived that the 
action of the 1% acid on the woods was distinctly feeble. These 
results are in full accord with those of Winterstein,t who found 
that much more of the xylan in beech wood was hydrolized by 
sulphuric acid of 5% than by that of 1.25%. 
In respect to the hexosans in date stones and the ivory nut, it 
will be noticed that the action of both the acids was more pro- 
nounced than it was in the case of the woods. But here again, 
contrary to E. Schulze’s experience with paragalactan,{ which he 
found to be about as readily soluble in hydrochloric acid of 1% as 
in a somewhat stronger acid, the weaker acid did less service than 
the stronger. It is not impossible, however, that by the persistent 
application of fresh portions of moderately strong acid, almost the 
* U.S. Department of Agriculture, Office of Experiment Stations, Bulletin 
No. 34, p. 13. 
+ Zeitschrift fiir physiologische Chemie. 17. 384. 
t Versuchs-Stationen. 36. 447; Landwirthschaftliche Jahrbiicher. 21. 
91, 94, 101. 
