VEGETABLE POOD. 263 
Pistacia nuts . . . (Pistacia vera). 
Cashew nuts . . . (Anacardium occidentale). 
Chicha nuts . . . (Sterculia Chicha). 
Pine seeds . . . (Pinus Pined). 
The seeds of many other species of plants are eaten, and the oil 
they contain is probably their chief recommendation. 
Amongst them may be mentioned the various forms of acorns which 
are eaten in Portugal, Greece, Asia Minor, and other parts of the world* 
The sacred bean of Egypt (Nelumbium speciosum), and the lotos 
(Nymphcea lotos) of the same region, the water- nuts (Trapa natans) of 
China and Cashmir, and the souari, or butter nuts (Caryocar buiryosum) 
of Demerara. 
A bread is made at Gaboon, in Africa, from the seeds of the 
Mangifera gdbonensis, called dica or odika bread. By simply boiling in 
water, from 70 to 80 per cent, of fat can be extracted from this bread. 
In this respect these seeds resemble chocolate, and it is not impossible 
that they might be used in Europe in the same way. They are exceed- 
ingly abundant in Gaboon. 
The seeds of many of the palms yield large quantities of oil, especi- 
ally the oil palm (Elm's guineensis) of Africa. The seed of the cocoa-nut 
palm (Cocos nucifera) is used as a substantive article of diet in Ceylon 
and many parts of the East Indies. It is imported into this country for 
the sake of the oil it contains. The milk in the interior of the seed is a 
blank fluid, and when the nut is fresh gathered, is a cool and pleasant 
drink. In the young state the seeds of most palms are filled with a 
cool fluid consisting mostly of water. This fluid is drunk by the inhabi- 
tants of the countries in which they grow. The double cocoa-nut of the 
Seychelles Islands (Loidicea Seychellarum) contains sometimes as much 
as fourteen pints of water, and is drunk by sailors touching on these 
islands with great relish. Even the hard ivory-nut (Phyteleplias macro- 
carpa) contains when young a fluid which is drunk by the natives of 
the countries in which it grows. 
Amongst vegetable fo©ds yielding oil the cocoa or chocolate plant 
(Theobromo cacao) is one of the most remarkable. The seeds of this 
plant contain 50 per cent, of a hard oil or butter. 
Food is sometimes preserved in oil which, on account of the small 
quantity of oxygen it contains, prevents animal or vegetable substances 
from putrefying. A familiar instance is known in this country in the 
case of the fish called sardines, which are thus preserved. Oil is used 
for this purpose in China. 
Acids. — Many of the organic acids resemble closely in their compo- 
sition starch and sugar, and may to a certain extent act on the system in 
the same way. They are therefore referred to the carbonaceous group, 
but there is no reason to suppose that in any system of diet they could 
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