Note on the Chemical Composition of some Mucilages, 
BY 
K. Yoshimura, Nögakushi. 
The mucilages or saccharo-colloids, hitherto analysed, 
have been found to consist, in most cases, of saccharo-polyan- 
hydrides of either glucose, galactose, mannose, or arabinose. 
Only in one case was the mucilage shown to consist of a mucin 
(Ishii, Vol. II. No. 2 of this Bulletin). 
Although such compounds are widely distributed in the 
vegetable kingdom, they have been investigated but in a very 
limited number of cases. As it is of physiological interest to 
know the composition of mucilages in as many plants as possible, 
I have examined those of the following species : 
1. Sterculia piatanifolia (young shoots). (I) 
2. Colocasia antiquorum (tuberous roots). (2) 
3. Opuntia (fleshy stem). 
4. Vitis pentaphylla (stems and leaves). 
5. Œnothera Jaquinii (stems and leaves). 
6. Kadzura japonica (young leaves and stems). 
The concentrated slimy extracts were precipitated with 
strong alcohol and the precipitates, after having been washed 
with alcohol, were boiled with sulphuric acid of 2-4 % for 2-5 
hours, the liquid neutralised with barium carbonate, and the 
filtrate evaporated to a syrup. 
A portion of this syrup was evaporated with nitric acid to 
observe whether mucic acid was formed. 
Another portion was mixed with a cold concentrated solu¬ 
tion of acetate of phenylhydrazine to observe whether mannose- 
phenylhydrazone was formed. 
(1) The mucilage of Sterculia platanifolia, as well as that of Kadzura japonica, 
finds technical application in this country, being used for sizing paper, etc. 
(2) The tuberous rootstock of Colocasia antiquorum serves as a valuable food in 
this country, and is hence cultivated to a large extent. 
