242 
Tlie Applicaiions of Physiology 
Attention to these considerations will easily point out the kinds 
of food which are best adapted for a growing animal. Thus 
potatoes, without an admixture with other food, would be highly 
improper, because they do not contain suflficient albumen to 
supply the materials necessary for the growing frame. But it 
would be quite proper to mix potatoes with other food rich in 
albumen, for its starch might support the respiration and heat 
of the animals with more economy than another food containing 
much albumen but a less abundant supply of substances fitted 
for respiration . 
It is a mistake into which many breeders fall to deprive the 
young animal of exercise by confining it entirely in the stall. 
Such a procedure is perfectly correct with a fattening calf, but 
not with one which is rearing. The muscular apparatus of a 
young animal requires a certain degree of exercise, without which 
it cannot increase. Unless the vitality residing in the various 
organs be called into action, it becomes enfeebled; and as vitality 
is the cause of increase in the body, any diminution of its power is 
highly prejudicial tA growth. The amount of exercise must of 
course vary with the age of the animal. A child at the breast 
sleeps twenty hours of the day, and consequently wakes only four. 
The vitality being in the ascendancy during sleep, the mass of 
the body rapidly increases. The limbs of a young child are not 
adapted for its support, and hence it is unnecessary to exercise 
them. But a calf or a sheep possesses limbs fitted for a certain 
amount of progression, and by permitting their due exercise the 
health of the animal is sustained. But whilst we should endea- 
vour, in the rearing of cattle, to use every means to keep the 
animal in its normal state of health, our treatment must be 
entirely different when we desire to fatten the same animal. 
II. In my last lecture I endeavoured to convince you of Liebig's 
theory, that every motion, however trivial, is accompanied by a 
waste of matter in the body. I proved to you also, by reference 
to your own experience, that the heat of an animal is supported 
by a combustion of the food which it consumes; and consequently 
that more food is necessary in cold than in hot weather. I cited 
in proof of this the beautiful experiments of Earl Ducie and Mr. 
Childers, and, in further confirmation of the same fact, I may 
bring forward the evidence of Mr. Morton, who assures me that 
" sheep will consume more turnips in the cold wet days of winter 
than when the weather is dry and warm, and in frosty weather 
than in mild, dry weather ; and the difference in their consump- 
tion,'' Mr. Morton states, " I find to be equal to one-fourth of the 
whole of their food."* Mr. Pusey also informs me that a farmer 
Answer to a question sent. 
