236 MAKITAL OF CATTLE-FEEDINO. 



ered. These are, in. this ease, the amomit of food, the 

 amount of water drunk, and the teuiperatiu-e. 



That the amount of food has an important influence on 

 tlie amount of carbonic acid excreted is a well-established 

 fact, and is well illustrated by a sev^ith experiment on the 

 same two sheep, in which all food was withheld for a single 

 day. The carbonic acid excretion sank at once to 837 

 grammes, or scarcely more than half that previously ob- 

 served. 



In these six experiments, however, although the amount 

 of fodder eaten varied somewhat, no ^ connection can be 

 traced between its amount and that of the carbonic acid. 



The same is true of the amount of water dnmk, while 

 the lowest temperature {ie.j the one which should cause 

 the greatest activity of the oxidations in the body) coin- 

 cides with the minimum of carbonic acid. 



"We must therefore conclude that there is a connection 

 between the carbonic acid excretion and the evaporation 

 of water, and that an increased evaporation causes more 

 material to be oxidized in the body, in order to make good 

 the resulting loss of heat. 



Henneberg's experiments are the only ones which we 

 yet possess on this important subject, but they suffice to 

 show its practical importance and the desirability of fur- 

 ther experiments in the same direction. 



A direct influence of the amount of water evaporated 

 upon the protein consumption does not seem to be indi- 

 cated by these experiments. 



Warming Ingesta. — ^A considerable quantity of heat 

 (according to Henneberg, about -i per cent.) is consumed in 

 raising the food and drink of an animal to the temperature 

 of its body. Of this amount, by far the larger part is 

 used in warming the water of the ingesta, both on account 



