to the Rearing and Feedliuj of Cattle. 
239 
Casein, although of the same composition as vegetable albumen 
and gluten, differs from them materially in its properties. It is 
soluble in water, and does not coagulate by heat. Such properties 
obviously fit it for the nutrition of a young animal, in whom the 
organs of digestion are not yet matured. 
The young ruminant, subsisting on the milk of its mother, 
does not require that complicated system of stomachs which after- 
wards becomes necessary for the proper comminution of its food. 
Accordingly we find that the aperture of the first and second 
stomach is entirely closed, and the folds of the third adhere to- 
gether so as to form a narrow tube. The milk passes at once 
into the fourth stomach, which is the seat of true digestion. This 
arrangement of itself indicates that the food of the young animal 
ought to be liquid, even when it is deprived of the milk of its 
p<arent. It is for this reason that the weaning of a calf must take 
place very gradually. 
There cannot be the slightest doubt that the future health and 
constitution of the adult in a great measure depends upon its 
judicious and generous treatment when young. Nature has 
pointed out to us, in the milk of the mother, not only the proper 
food of the child, but has exhibited also in it the model after 
which all food should be prepared. I do not mean that the adult 
should receive the various constituents of its food in the same 
proportion as the child, but that none of these constituents should 
be absent. In the milk of the cow, the amount of unazotised 
matter, or of the part of milk destined for the support of respira- 
tion, is only about double that of the azotised portion, or of that 
part which forms flesh. In the food of adult cattle the propor- 
tion of the former to the latter is about six to one. But the un- 
azotised constituents of the food of adults consist principally of 
starch, sugar, and gum, whilst those in the food of children con- 
sist of butter and sugar. The butter contains a very large amount 
of carbon and of hydrogen, and, therefore, a less quantity of it suf- 
fices to sustain the heat of the body than of any of the other sub- 
stances now mentioned. Thus milk is actually better adapted 
for the support of the rapid respiration of a young animal than 
other kinds of food. The large proportion of casein in milk is 
obviously indispensable to furnish materials for the rapid increase 
of the body. 
Any interference with the order of nature in the rearing of 
young stock is improper. But it sometimes occurs in England 
that calves .are allowed to suck only for a few days, and after- 
wards are fed upon skimmed milk. In separating cream from 
milk, we remove most of its butter, as well as part of the casein. 
Skimmed milk is therefore destitute of the principal ingredient 
destined by nature for the support of respiration and sustenance 
