THEORIES OF ANIMAL HEAT. 643 



Is it then possible, after having proved by 

 so many accurate experiments, that the tempe- 

 rature of blood is elevated from 1 to 3 while 

 passing through the lungs, and reduced to its 

 former state while passing through the general 

 system, that this intelligent physiologist should 

 have overlooked the fact, that arterial contains a 

 larger proportion of organic matter than venous 

 blood? And is it not admitted by all physiolo- 

 gists, that every part of the body is nourished 

 at the continual expense of arterial blood ? Dr. 

 Edwards maintains that the temperature of ani- 

 mals depends greatly on the proportion of red 

 particles in their blood, because the lower orders, 

 in which it consists chiefly of water, are cold 

 blooded. But this is only one among a thousand 

 examples that might be adduced, of the manner 

 in which men have inverted the laws of nature, 

 or confounded cause and effect. For as the me- 

 chanical physicians, including Boerhaave and 

 Haller, regarded animal heat as an effect of the 

 heart's action, motion of the blood, and its friction 

 against the solids ; so did Sir H. Davy regard it 

 as " a result of all the changes arid organic actions 

 that take place in animal bodies." And so effec- 

 tually has the chemical theory of respiration been 

 shaken by his denial that caloric is a material 

 agent, that Mason Good " omits the consideration 

 of it," while he defines " respiration as the act 

 of receiving oxygen, and throwing out carbonic 

 acid." 



