IN THE ANIMAL ORGANISM. 253 



the combination of the oxygen with the elements of 

 the metamorphosed tissues, a greater amount of 

 heat is liberated. 



For a given amount of oxygen, the heat produced 

 is, in all cases, exactly the same. In the cooled 

 part, the change of matter, and with it the disen- 

 gagement of heat, increases ; while in the other 

 parts the change of matter and liberation of heat 

 decrease. But when the cooled part, by the union 

 of oxygen with the elements of the metamorphosed 

 tissues, has recovered its original temperature, the 

 resistance of its living particles to the oxygen con- 

 veyed to them again increases, and, as the resistance 

 of other parts is now diminished, a more rapid 

 change of matter now occurs in them, their tempe- 

 rature rises, and along with this, if the cause of the 

 change of matter continue to operate, a larger 

 amount of vital force becomes available for mecha- 

 nical purposes. 



Let us now suppose that heat is abstracted from 

 the whole surface of the body ; in this case the 

 whole action of the oxygen will be directed to the 

 skin, and in a short time the change of matter 

 must increase throughout the body. Fat, and all 

 such matters as are capable of combining with the 

 oxygen which is brought to them in larger quantity 

 than usual, will be expelled from the body in the 

 form of oxidised compounds. 



