2o6 kinoshita ; mannans in c. konyaku. 
could be made in regard to its rotatory action upon polarised 
light. Upon drying at ioo°, it lost its solubility in boiling water 
entirely. Upon boiling with 4% sulphuric acid for several 
hours mannose was also obtained from it. The property of losing 
its solubility upon drying proves that this mannan is different 
from that separated from yeast by Salkowski, {1) with which it 
agrees, however, in the following respects :— 
Basic lead acetate—no precipitate ; basic lead acetate and 
ammonia—thick precipitate; ferric chloride and ammonia— 
gelatinous precipitate ; copper sulphate and sodium hydroxide— 
thick blue precipitate ; and the same by Fehling’s solution. 
It seemed to me of interest to determine whether the diastase 
of malt, invertase, or emulsin would have saccharifying power 
over this slimy mannan of konyaku, and this I tried and found 
not to be the case ; its slimy character remained, although I 
digested it with the enzymes mentioned for 5-6 hours at 40°— 
6o°, and no sugar was formed. 
That this mannan is also digested with much more difficulty 
than starch, has been shown by Prof. Osawa's experiments 
on dogs. An enzyme endowed with saccharifying power for 
mannan must, however, exist in the konyaku- root, and I intend 
to try to isolate it in the season when the root is in the state 
of developing shoots. 
(1) Ber. d. chem. Ges., 1894. p. 499. 
