g8 
ON THE OCCURRENCE OF MUCIN IN PLANTS. 
Composition of the yam. 1 ) 
Water 
80.74 
100 parts of dry matter, 
Crude protein 
11-74 
Fat 
0.84 
Fibre 
4 - 3 6 
Ash (free from Co 2 ) 
3.6° 
Starch 
22.13 
Other non-nitrogenous substances. 
57-33 
Total nitrogen 
00 
• 
H 
Nitrogen in amides, etc. 
0.675 
2- Preparation of the Slime of Yams. 
The slimy matter forms a thick turbid liquid and can 
be easily freed from starch granules and other substances by 
simply filtering. The filtered liquid shows a neutral reaction, 
and is precipitated by the addition of acids, but the pre¬ 
cipitation is prevented to a certain extent by the presence of 
common salt. Several methods are proposed for the isolation of 
mucin. 
Landwehr 2 > prepared the mucin of the bile by precipitating 
with acetic acid, washing, dissolving in i%, solution of soda, 
and precipitating again. Obolenski 1 2 3) recommended a method of 
purifying the mucin of the submaxillary glands as follows : The 
glands are soaked in water over a night and filtered. The filtrate 
is precipitated with acetic acid, the precipitate washed first 
with water and a little acetic acid, then with hot alcohol and 
finally dried. But Hammarsten 4) recommended a new method 
which is well adapted to separate mucin from substances belong¬ 
ing to the group of nucleoalbumins. The mucin of the sub¬ 
maxillary glands is soluble in dilute hydrochloric acid (o.i— 
0.2%) and is precipitated unchanged by adding 3 or 4 times 
its volume of water to the solution, while the nucleoalbumin 
dissolves in dilute hydrochloric acid together with the mucin, 
1) The analysis was made in the agricultural chemical laboratory of the Im¬ 
perial College of Agriculture in Tokyo. See Bull. Vol. I. 
2 ) Z. physiol. Chem. Bd. V, 371. 
3) Pflüg. Arch. 4. 
4) Z. physiol. Chem. Bd. XII. 
