134 
Selected Articles, 
ART. XXX.— ON THE MANIOC, AND ANALYTICAL EXPERIMENTS 
ON THE JUICE OF ITS ROOT. By O. Henry. 
The Manioc (Jatropha manihot, Janipha manihot,) of the 
family of the Euphorbiacese, is a plant indigenous to America, 
and the cultivation of which is much attended to from Florida 
to the Straights of Magellan, as well as in many parts of Asia 
and Africa. In fact, this plant furnishes one of the principal 
sources of food to the inhabitants of these countries. There 
are two kinds of manioc, the bitter and the sweet, both of 
which are cultivated and afford different products ; the bitter 
manioc, notwithstanding the active poisonous principle it 
contains, is the most esteemed, and yields the largest pro- 
duct; it is well known that this dangerous principle is dissi- 
pated or destroyed by the action of heat, and it is then easy 
to extract from the root a substance that is extremely nutri- 
tive both to man and animals. All authors agree in their 
accounts of the methods employed to extract this alimentary 
product, hence I shall not dwell on this point, but will merely 
present some details which I trust may prove interesting, as 
they were obtained from actual observation. I am* indebted 
for them to Dr. Sureau, who, having lived for ten or twelve 
years in St. Domingo, has had numerous opportunities of in- 
specting every part of the process. 
The Janipha manihot presents, as I have before said, two 
very distinct varieties, one sweet, and not poisonous; the 
other bitter, containing, besides the alimentary principle, a 
violent and subtle poison ; this latter kind is the most gene- 
rally cultivated. 
It is difficult to distinguish the roots of these two varieties 
from each other ; but on closely inspecting them, it will be 
perceived that in those of the sweet manioc, there are lig- 
neous fibres towards the centre, which are not found in the 
bitter ; and moreover, the first becomes soft by boiling, whilst 
the other does not. From these roots are prepared, cassava, 
iapioca and flour of couscous. 
To obtain cassava, roots of the size of the arm are washed 
