Respiration. 95 



animals experimented upon by me, though of necessity 

 some slight loss must have occurred in the short time 

 elapsing between the termination of the work and the com- 

 munication made between the animal and the respiratory 

 apparatus. 



I was surprised to rind how greatly the respiratory pro- 

 ducts at the same pace and in the same horses varied, and 

 I do not believe it to be possible to obtain anything like 

 exact results with animals performing work in a natural 

 manner. 



M'Kendrick, quoting from Munk, gives the following 

 table of respiratory changes in animals : 



Gases of Rkspikation in 24 Houus. 



The oxygen requirements of an animal bear no propor- 

 tion to its size : a small singing-bird will use up, per unit of 

 body weight, ten times as much oxygen as a hen. In the 

 human subject it has been shown that the nature of the 

 diet influences considerably the amount of CO., excreted 

 and absorbed. The C0. 2 is increased by giving food rich 

 in starch ; fats have not such a marked effect in this 

 direction, whilst albuminoids increase the absorption of 

 oxygen. 



