392 BULLETIN OF THE BUSSEY INSTITUTION. 
obtained with malt, as stated on page 389, that most of the sugar 
formed by the action of acids in these experiments, must have 
come, not from starch in the wood, but from hemicelluloses of one 
kind or another, presumably from pentosans for the most part. 
In the absence of certainty as to this point, an attempt has been 
made to get a rough conception of the quantity of pentosans by 
proceeding as if the copper found represented dextrose; 7.e. dex- 
trose was computed from the copper, by means of Allihn’s table, 
and this so-called dextrose, which was presumably xylose for the 
most part, was multiplied with the factor 0.88 * to convert it into 
terms of xylan.t 
In the cases of the ivory nut and date stones, which are rich in 
mannan and poor in pentosans, the sugar obtained by the action 
of acids has been calculated as a hexosan by multiplying with the 
factor 0.9. Speaking in a general way, the reducing action of 
xylose and dextrose upon copper salts is very nearly the same, ft 
but the details of the action of xylose appear never to have been 
_ worked out. 
Pentosans obtained from Woods by means of Sachsse’s Acid, i.e., 
Acid containing about 24 per cent of HCl. 
Kind of Wood. Per cent of pentosans (wood dry at 100° C.). 
Inner Wood. Outer Wood. Bark. 
Gray Birch felled in May ... . . 22.00 25.25 22.91 
- ae BS SS SLY cai ar. ee eee 22.16 21.49 
de de a6 $6) October: i... ins Oana (1.) 24.55 28.93 
af ay es ttt af sis 2} et eee (II.). 23.85 
Alder oc JANUAIY mous ee ee 25.63 26.15 
Sugar Maple ** ‘* October. . . . 19.59 20.47 
White Pine (unknown) « . 5 .,. 9 a) eee ey os 
Apricot Stones $9.5 204" 2 Gees yy ar 
Peach Mee ie bcos tes “Seta ge NGS dae ie ce 
Ivory Nut (paramannan) ....'. . . . 82.30 
Date Stones ‘ siusvesica (Lee Oi Two different samples. 
he ad 3 sale dite OLE e yee 
When the woods were subjected to a less severe treatment with 
acid than obtains in Sachsse’s process, 7. e., when they were boiled 
$y Ree 132 iN Molecular weight of xylan (CsHsO4) 
’ 150 = Molecular weight of xylose (C5H10035) 
+ Compare E. Schulze, Versuchs-Stationen. 836. 457, 460 note; 41. 228; 
and Winterstein, Ibid. 41. 378. 
t~ Stone, American Chemical Journal. 18, 82. 
§ The hard outer shell which encloses the kernel. 
