128 THE LAWS OF ORGANIC 



ally possess, the additional quantity necessarily 

 impedes the oxygenation and circulation of the 

 blood ; and, in proportion as these essential con- 

 ditions are disturbed, we shall find that the facul- 

 ty of generating animal heat is diminished, because 

 this is more powerfully influenced by the more ge~ 

 neral distribution of the blood in early life, and not 

 that it was originally less, as contended for by Dr 

 EDWARDS. 



CXXXV. To prove the correctness of these 

 principles, we shall examine the various causes 

 which, agreeably to Dr EDWARDS' opinion, mo- 

 dify the generation of animal heat. It is stated 

 by him, that the temperature of animals is capa- 

 ble of being most diminished by the artificial ap- 

 plication of cold in summer, because the power 

 of producing heat is less at this season. 



CXXXVI. Summer produces a character of 

 circulation essentially similar to that peculiar to 

 infancy and childhood. The capillary vessels are 

 not constricted, as in winter, thereby determin- 

 ing the blood within, but are excited to greater 

 action from the application of heat ; therefore the 

 blood is more equally diffused throughout the sys- 

 tem, offering, as in infancy, an increased surface 

 of blood to the action of cold so applied. 



CXXXVII. An animal, in accordance with 

 this explanation, will suffer sooner from the in- 

 fluence of artificial cold in summer than in win- 

 ter ; and this is fully verified by the experiments 



