8. The Composition of Indian Yams. 
By Davin Hooper. 
In the Report of the Industrial Section, Indian Museum, 
for 1903-04, reference was made to the examination of a large 
number of tubers of species of Dioscorea, collected by the 
Reporter on Economic Products to the Government of India. 
About 30 kinds of these roots had been analysed with a view 
to determine their comparative food value. Since that time 
further varieties of the roots from plants, critically determined 
by Mr. I. H. Burkill, have been examined; and it has been 
considered desirable to publish the collective results. Since 
som these roots have, in their natural state, poisonous 
properties, and are eaten after being washed and cooked, an 
investigation has been made of the effect of washing by show- 
ing the composition of the tuber before and after tue process. 
Tubers of authenticated plants have been tested for poisonous 
principles and a record has been made of those species in which 
they are either present or absent, with remarks on the influence 
of cultivation in reducing the noxious properties. In the 
majority of cases the roots were received in a fresh condition, 
they were dried in the sun or in warm air, and the chemical 
examination was made on the powdered root. The amount of 
moisture in the fresh tubers ranged from 70 to 85 per cent., but 
the results of the analyses, for the sake of comparison, are 
exhibited in the following table calculated to the absolutely dry 
sample. 
The tubers of the following species and varieties of Dioscorea 
were examined :— 
D. aculeata (No. 20490), ‘‘Chaee,’’ N. Thana, Bombay. 
D. alata (No. 20671), Fiji, skin and flesh white. 
» (No. 20676), Fiji, purplish on drying. 
,, (No. 20688), Fiji, skin and flesh pink. 
oF Aérial tubers, Basirhat. 
D. alata, var. farciniformis (18113), Ganjam. 
Bs 18972), Jalpaiguri. 
globella (17751), Trichinopoly. 
sacciformis, ‘‘ Myauk-u,’’ Burma. 
rubella (No. 18942), Salem, flesh yellow. 
as ,» purpurea (No. 19566), Bhopal, C.L. . 
D. anguina, small tubers. 
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39 b 
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