OF THE POTATOE. 427 
This per-centage has not been added in the 
table. It disappears in boiling, for the water is 
not tinged by it. Its taste is acrid, being perhaps 
that principle which renders the tuber unwhole- 
some when raw, and to which it owes its botanical 
name, solanum tuberosum. It possesses this pro- 
perty in common with many of the starch-bearing 
plants of the tuberous kind. The Cassada, Ja- 
nipha or Jatropha Manihot, called Cassava when 
made into flour, and from which also the tapioca 
is prepared, is poisonous in its raw state, the 
poison being said to consist in a volatile oil. The 
Arums also, of which the Arum Macrorhizon, 
Arum Colocasia, and Caladium Acre, are culti- 
vated in the South Sea Islands, and are called 
Tarro by the natives, possess equaliy deleterious 
qualities when fresh ; but upon the application of 
heat, are deprived of their virulence, supplying a 
bland and nutritious food to the inhabitants, and 
are preferred by them to other kinds of food pos- 
sessing similar qualities. 
The following experiments were made with 
the view of ascertaining whether the starch was 
equally distributed throughout the potatoe. 
