ON THE CONSTITUENTS OF RUSH-PITH. 
95 
of 1.2 grams of arabinose-benzylphenylhydrazone, io grams of alcohol, 
and i gram of benzaldehyde was heated on water bath, in a small flask 
provided with a reflux condenser. At the end of 4^ hours an oily liquid 
was formed, which on cooling solidified into a crystalline mass. ~ On recry- 
stallization from alcohol, fine needles were formed whose melting point was 
found to be no 0 . The melting point coincides with that of benzal-benzyl- 
phenylhydrazone and shows that decomposition of arabinose-benzylphenyl- 
hydrazone had taken place. The filtrate from benzal-hydrazone was shaken 
with ether in a separating funnel three times and the watery solution was 
then evaporated. On cooling, crystals began to show themselves in the 
syrup. They were separated by filtration, washed with absolute alcohol and 
ether and finally dried over sulphuric acid in vacuum. The sugar thus 
obtained was slightly colored, but further purification was not attempted 
because of its small amount. 
0.2566 gram of the sugar was dissolved in water, a few drops of alumina 
cream added and then made up into 25 c.c. and polarized in 200 mm. tube. 
Ki-rotation was observed. At the end of 24 hours a dextro-rotation of 6.1 
on the scale was noted, The specific rotatory power is 
[a] 
D = 
6.1 x 0.346 x 25 
0.2566 X 2 
-f- 102.8° (at 20°) 
The observed specific rotatory power coincides closely with that of 
arabinose. Isolation of arabinose from the syrup is hereby fully 
demonstrated. 
Summary. 
The chief results of the present investigation will be here recapitulated. 
We have succeeded, first of all, in isolating xylose (in comparatively 
large amount), as well as arabinose, from the hydrolysis product, by tedious 
and painstaking processes. The pentosan of rush-pith is therefore 
made up of both xylan and araban, the former, however, predominating in 
amount over the latter. 
The fact that both xylan and araban were proved to exist together in 
the pith, is of special interest. So far, the co-existence of two kinds of 
