52 
T. TADOKORO. 
b) 0.1895 gram of dry matter dissolved in 40 c. c. of 1% caustic potash i 
solution. 
0.9 x 0.346 x 40 
Detection of Xylose. 
The syrup gave the following reactions : 
1) . It reduced Fehling’s solution very strongly. 
2) . It rotated the plane of polarization toward the right. 
3) . It gave the characteristic absorption-spectrum of pentose with 1 
pliloroglucin and hydrochloric acid. 
4) . It produced no mucic acid upon oxidation, with nitric acid. 
5) . It gave no ketose reaction with resorcin and hydrochloric acid. 
6) . 2 drops of the syrup were placed on an object glass and were seed- 
ed respectively with a crystal of xylose and of arabinose. After 48 
hours the drop seeded with xylose showed the formation of many 
new crystals, while the other remained unchanged. 
From the above reactions it is highly probable that the syrup contained i 
xylose. 
Isolation of Xylose. 
The syrup was left untouched about one week, when it was found 
thickly laden with fine crystals. A little amount ©f. 85% alcohol was added 
to the syrup, well mixed, filtered with suction, and washed with absolute 
alcohol and ether. The sugar thus obtained was 2.5 grams in weight and 
slightly yellowish in color, but upon recrystallization from alcohol with the use 
of animal charcoal, it became perfectly white and left no ash on ignition. 
1.13 grams of the carefully dried sugar was dissolved in water and made 
up into 25 c. c. and polarized in 200 mm. tube, in the half shadow polariscope. 
Strong birotation was observed. 
After 24 hours, the rotation was found to be 4.75° on.' the scale toward the 
right. The specific rotatory power is 
4.75x0.346x25 
aT> = 
1.13x2 
- = 18.2° 
