94 
K. OSRJMA. 
4) Isolation of Arabinosc. 
The mother-liquor filtered off from the second crystals of xylose was 
allowed to evaporate slowly by itself. It did not show any sign of forming 
new crystals of its own accord, after long standing. Trial was made to 
induce the formation of crystals by seeding with xylose or arabinose, but 
the effort was in vain in both cases. Attempt was then made to separate 
and detect arabinose by use of benzylphenylhydrazin, according to the 
method of RUFF and OLLENDORF. 1 ' Benzylphenylhydrazin easily forms 
with arabinose a hydrazone, which is hardly soluble in 75% alcohol, while 
xylose-hydrazone is easily soluble in the same medium. Thus it affords an 
excellent means of separating the two sugars from each other. 
7 grams of the syrup were dissolved in 20 grams of 70% alcohol, to 
which a solution of 5 grams of benzylphenylhydrazin in 9 grams of absolute 
alcohol was added and the mixture well shaken. The fluid soon became 
turbid and in course of 3 hours abundant crystalline precipitates were 
formed. The crystals were separated by filtration with suction, washed with 
a small amount of 75% alcohol and finally recrystallized from 95% alcohol. 
The product obtained in this manner was perfectly white and weighed 1.45 
grams when dried over sulphuric acid in vacuum. The melting point was 
found to be i6g 0 -i70° which coincides with that of arabinose-benzylphenyl- 
hydrazone. 
0.2054 gram of the substance was dissolved in 50 c.c. of methyl alcohol 
and polarized in 200 mm. tube. A levo-rotation of 0.3 on the scale was 
observed. The specific rotatory power is 
= 0.3 x 0.346 x 50 | _ I2 (P (at 
L J 0.2054 x 2 
The specific rotatory power of arabinose-benzylphcnylhydrazone, ac- 
cording to van Ekenstein and de Bruyn 1 2) is -i 4.6°, while Browne 
and TOLLENS 3) found it to be -12. i°. 
For the separation of arabinose from its hydrazone, benzaldehyde was 
used. The operation was carried out in the following manner. A mixture 
1) Berlin, Ber. D. chem. Ges. 32 (1899) p. 3234. 
2) Berlin, Ber. D. chem. Ges. 29 Ref. p. 91 1. 
3) Mid, 35 (1902) p. 1461. 
