222 
The Applications of Physiology 
their bodies from the cold. Warmth is an equivalent for food, 
which may thus be economised. But I wish to give you facts, 
not assertions ; and as a proof of the view I have now given you, 
I will cite the following experiment which was made by the Earl 
of Ducie at Whitfield farm. 
One hundred sheep were folded by tens in pens, each of which 
was 22 feet in length by 10 feet in breadth, and possessed a 
covered shed attached to it of 12 feet in length by 10 feet in 
breadth. They were kept in these from the 10th of October to 
the 10th of March. Each sheep consumed on an average 20 lbs. 
of swedes daily. Another hundred were folded in pens of a 
similar size, but without sheds attached. They were kept during 
the same time, and their daily consumption of swedes amounted 
to 25 lbs. each. Here the circumstances were precisely similar 
with respect to exercise, the only difference being that the first 
hundred sheep had sheds into which they might retire, and thus 
be partially protected from the cold. 
This partial protection was equivalent to a certain amount of 
food, and consequently we find that the sheep enjoying this pro- 
tection consumed one-fifth less food than those sheep which were 
left entirely exposed to the cold. In the last case the consump- 
tion of the additional food arose wholly from the necessity of 
adding more fuel (food) to the furnace of the body, in order to 
keep up its normal temperature. This was proved from the 
circumstance, that those sheep which enjoyed the protection had 
increased 3 lbs. each more than those left unprotected, although 
the latter had consumed one-fifth more food. 
I do not, at this stage of the inquiry, refer to Mr. Childers's 
beautiful experiments on feeding sheep in sheds, as these involve 
another theory which has not yet been discussed. 
I wish particularly to impress upon you that warmth is an 
equivalent for food, and that, therefore, food may be economised 
by protecting cattle from the cold. The honey stored up by bees 
is for the purpose of serving as fuel to keep up the heat of their 
bodies during the winter. Now it has been found that when two 
hives of bees are placed in one hive during winter, that they 
actually consume less honey than each hive would have done 
separately.* You will easily perceive the explanation of this 
circumstance from the facts which I have already stated. Their 
close contiguity prevents a rapid escape of the heat of their bodies, 
and consequently less fuel (honey) is required to keep up the 
temperature. This case forms a very distinct proof that warmth 
is an equivalent for food. 
But I need only refer you to the results of your own experience. 
* Transactions of the Ojcford Apiarian Society. 
