42 



we are enabled, by the progress of physical and physiolo- 

 gical science, to account for animal heat by the chemical 

 changes induced by vital and physical influences on the 

 combinations of the elements, of the several pabula vitse, and 

 of the component parts of the body. 



In the appended table is a summary of the mean results 

 obtained by Dr. Davy, from repeated observations upon the 

 three classes of warm-blooded animals ; among these, on 

 forty-four men in three quarters of the globe, in different lati- 

 tudes, under various temperatures, and among individuals of 

 different races — thirty- one species of the other mammals, 

 and fifteen species of birds, all of different orders. Along 

 with the mean are given the extreme temperatures of each 

 class. In the table are also shewn the mean and extreme 

 temperatures of the air when the observations were made. 

 In all these observations, the subjects were in perfect health ; 

 but, as the lowest temperature of the air at which the 

 observations were made may be considered warm, and as it 

 will be shewn that the effect of increased temperature of the 

 air is to raise the temperature of the, body, the numbers 



