226 
The Ajyplications of Physiology 
When prizes formerly were given for animals overloaded with 
fat, without reference to symmetry of form, it was customary to 
feed the sheep in a narrow confined shed from which the light 
was excluded. The animals having no inducement to roam 
passed most of their time in sleep, and the food which they con- 
sumed served only to keep up the animal heat, and to increase the 
mass of the body. 
Mr. Childers has made some beautiful experiments on this 
subject, the results of which have shown that sheep fed in sheds 
consume from one-fifth to one-half less food, and increase one- 
third more in weight, than those fed in the open field.* The 
cause of these results is twofold : — First, the sheep in the sheds 
are subjected to less motion, and therefore exhaust less food in its 
production than those in the field ; and, secondly, the sheep are 
kept warm in the sheds, and therefore expend less food for the 
support of animal heat than those exposed to a cold atmosphere in 
the open fields. 
We know how difficult it is to fatten oxen in June and July, 
when the flies annoy them, and disturb their repose. The food 
which they consume is exhausted in motion. This food, if the 
oxen were in a state of tranquillity, would increase the mass of 
the body. We know also that the harassing and worrying of sheep 
by dogs is fatal to their fattening. 
There are numerous other proofs of our view. The Cornish 
miner, from the expenditure of force necessary in ascending and 
descending the ladder of his mine, together with the labour which 
he has to undergo whilst in it, is found in the evening to be seve- 
ral pounds lighter than in the morning. It is well known that 
the more bodily labour to which a man is subjected the more 
food must he receive to supply the tissues wasted in that labour. 
In the late distress in Lancashire, the poor sufferers, who often 
were unable to obtain sustenance for themselves and families, dis- 
covered, through the force of necessity, both the theories which 
we have endeavoured to expound, viz., that warmth is an equi- 
valent for food, and that motion is always accompanied by a change 
of matter. We are informed by the daily press that whole fa- 
food was boiled potatoes. They were all killed on the 13th of April, and 
the weights were as follows (8 lbs. to the stone) : — 
The hog in the cage 13 st. 2 lbs. 
The average weight of the other hogs, all of the same breed . 11 st. 3 lbs. 
The hog in the cage was weighed before he was put in : alive 11 st. 1 lb. ; 
he was kept live weeks, and then weighed alive 18 st. 3 lbs. He had two 
bushels of barley-meal, and about eight bushels of potatoes. He was quite 
sulky for the first two days, and would eat nothing." 
This experiment forms an excellent illustration of the theory that force is 
produced by an expenditure of matter. 
* Trans. Royal Agric. Soc. of England, vol. i. pp. 170 and 407. 
