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K. MIYAKE & T. TADOKORO. 
for about 12 hours, when a blackish gummy substance adhered to the sides 
and bottom of the flask. The fluid was decanted and concentrated again in 
a partial vacuum to about 80 c.c. . To the remaining syrup, about 500 c.c. 
of 95% alcohol were added. This produced a second precipitate of a yellow- 
ish gummy substance. After standing for a few hours, the clear solution 
was decanted and concentrated to a small volume in a partial vacuum. The 
syrup was once more purified by shaking with about 200 c.c. of absolute 
alcohol. A clear solution was decanted and evaporated down to about 50 c.c. . 
(2) Qualitative tests of the syrup. 
The syrup gave the following reactions 
a) It reduced Folding’s solution very strongly. 
b) It rotated the plane of polarization toward the right. 
c) It gave the characteristic absorption -spectrum of pentose with phloro- 
glueiu and hydrochloric acid. 
d) Two drops of the syrup were placed on an object glass and were seeded 
respectively with a crystal of xylose and arabinose. After 36 hours, 
the drop which had been seeded with xylose showed the formation 
of new crystals, while that with arabinose remained unchanged. 
From the above reactions it is safe to conclude that the syrup contained 
pentose and that the presence of xylose was highly probable. 
(3) Isolation of xylose. 
When the purified syrup was left untouched nearly one week, it was 
found thickly laden with fine crystals. A small amount of 85% alcohol was 
added to the syrup, well mixed, filtered with suction and washed with abso- 
lute alcohol and ether. The sugar thus obtained was slightly yellowish in 
colour but upon recrystallization from alcohol with the use of animal char- 
coal, it became perfectly white and left no ash on ignition. The pure air- 
dry sugar thus obtained was 3 grams in weight. 
0.425 gram of the carefully dried sugar was dissolved in water and made 
up into 25 c.c. and polarized in 100 mm. tube, in Schmidt and Haensch 
half shadow polariseope. Strong bi-rotation was observed. After 24 hours 
