1S8 PHYSIOLOGY OF ORGANIC LIFE. 



ing, unanimous m opinion, that it was the 

 source and the cause of animal heat, ff such 

 an hypothesis were true, it must, as a conse- 

 quence, follow, that the temperature of the 

 blood must be higher at the point near which it 

 is received* than in the most remote parts from 

 if ; find that the blood on the left side of the 

 heart ought, in that case, to be hotter than the 

 blood on the right side of it. The fact, how- 

 ever, is precisely the reverse. The experi- 

 ments made by Mr. A. COOPER, (and there is 

 no man more able, or more to be depended 

 upon,) show, in a manner the most decisive, 

 that the blood on the right side of the heart, at 

 the greatest possible distance whence the matter 

 of heat is supposed to be received, was from 

 two to three degrees hotter than the blood on 

 the left side, the nearest point to the supposed 

 source of heat. If the hypothesis, therefore, is 

 admitted to be true, we must also admit the 

 absurdity, that a body is heated to a greater 

 degree when situated at a great distance from 

 a fire, than when it is placed close to it. 



How the gaseous matter received from the 

 lungs, acts upon the blood, except by changing 

 its color and consistency, is as unknown at 

 present, as the operation of medicine upon the 

 stomach. The causa operandi of medicine ip 

 altogether unknown, and the modus operandi is 

 only acquired by experience, obtained through 



