ON THE RAINFALL IN THE BRITISH ISLES. 



RAIX-GAUGES {eoniimied). 



229 



These methods have been two, of which the one may be said to be indirect 

 and the other direct; each, if properly carried out, shoiUd lead to most 

 valuable results. 



The first method which suggests itself is to determine the temperature of 

 the blood m the right and left ventricles of the heart of a living animal If 

 our mode of experimenting were free from faUacy, and it resulted that the 

 lett side of the heart contained blood warmer than that of the rio-ht side 

 there would be no doul)t as to the evolution of heat during the absorption of 

 oxygen m the lungs ; if, on the other hand, the temperature of the left side 

 were the same as that of the right side, or lower, the question would still 

 remain an open one, for heat might be evolved by the condensation and 

 combination of oxygen in the lungs, yet the quantity might not be sufficient 

 to counterbalance the loss of heat due to the evolution of large quantities of 



