248 
K. OSH IMA & T. TADOKORO. 
cinchonin remaining in solution. The watery solution was then concentrated 
to a syrup. On cooling, the crystals of cinchonin salt began to show them- 
selves in the syrup. After 24 hours standing, the crystalline mass was mixed 
with about 3 c.c. of water, filtered and washed with a little cold water. 
Colorless needle shaped crystals were obtained, upon recrystallization from hot 
water, using animal charcoal. Its yield was 0.55 gram. The melting point 
was found to be 208-209°. The Specific rotatory power as determined by 
Schmidt and Haensch half shadow apparatus was as follows 
Wd = 
2.1 x 0.346 x 25 
= +177.1°. 
0.1017 x 1 
0.1934 gm. substance dried at 105° gave 1.321 mg. N. 
Calculated for CoHio08(Ci<)H22N20)2 = N 7 . 02 % 
Found = N 6.89 ^ 
The observed physical constants and analysis clearly 
indicate that the substance under examination is cinchonin 
norisosaccharate. The presence of glucosamin group in 
the yam mucin is hereby fully demonstrated. 
Hydrolysis of the Residue. 
The hydrolysis products of the protein group of true mucins have receiv- 
ed but little attention, owing no doubt chiefly to the difficulty of obtaining 
sufficient material for the investigation. As a larger portion of the yam mucin 
used for the separation of glucosamin by hydrobromic acid, in the previous 
experiment, remained apparently not much affected, we have undertaken to 
utilize this residue and study the nature of its cleavage products. 
The residue, after being dried at a low temperature to drive off the 
remaining hydrobromic acid, was hydrolyzed bv heating with 50 c.c. of 25 % 
sulphuric acid, first in a water bath for 2 hours and then on a sand bath for 
12 hours. On cooling, the hydrolysis solution was diluted with 100 c.c. of 
water, filtered and the filtrate neutralized with baryta. The barium sulphate 
which separated was sucked out and washed thoroughly by repeatedly boiling 
