CHEMISTRY IN AGRICULTURE AND PHYSIOLOGY. 341 
What is its first food? Is the process of nutrition still 
simple in its character ? It is, for life in the mammalia is main¬ 
tained, and every organ and every tissue of the body grows 
rapidly, while the animal receives for its nourishment but a 
single fluid, milk . 
The more exact analysis of the process of nutrition will 
show that the young animal receives in the milk every con¬ 
stituent of the blood of its mother. The constituents of 
milk are, caseine and fatty matter. 
At first sight the nutritive process in the adult animal 
appears to be quite different; but chemical researches have 
shown, that in the seeds of the different kinds of grain, and 
of peas and beans, in the roots and juices of what are com¬ 
monly called garden vegetables, there exist in larger or 
smaller quantity, three substances—these have been named 
vegetable caseine, albumen and gluten. The investigations 
of physiologists have established, as a rule without exception, 
that the food of the graminivorous animal always contains 
one or more of these compounds. It appears that if these 
be excluded, no other food can keep up in these animals the 
vital process. 
If fresh-drawn blood be rapidly “whisked” with a few twigs 
of wood, a gluey matter will be found adhering to them; this 
substance is known as “ animal jibrineT 
If wheat flour is placed in a linen bag, and water allowed 
to flow upon it, and the flour squeezed with the hands until 
the fluid passes through perfectly clear, the water removes 
the starch and albumen, but leaves in the bag a gluey sub¬ 
stance, called gluten or vegetable fibrine. 
When the serum of the blood, which forms 80 per cent, of 
that fluid, is boiled and the water evaporated, a grayish-white 
substance, albumen , is obtained. 
When the clarified juice of wheat is made to boil, a coa- 
gulutn is formed, albumen , which it is impossible to distin¬ 
guish from the substance which separates from the serum 
of the blood. If we rub down peas, beans, or green corn, to 
a thin paste, dilute this with water, and pass the mixture 
through a fine sieve, caseine is obtained in large quantities 
from the supernatant liquid. 
(To be continued .) 
XXXIII. 
43 
