On the Mechanism of Chemical Temperature Regulation. 209 



obviously improbable, and is vitiated by the fact that in his calculations he 

 neglected the latent heat of the fluid subcutaneous fat. Tins fat, on 

 solidification, would give out large quantities of heat, while, owing to the 

 lack in definition of its melting point, it falls but slowly in temperature. 

 A layer of warmer material is thus retained next the deep surface of the 

 skin in which the end organs for cold lie. Eubner (25) states that at the 

 " cooler places " a fat rich in olein is deposited. I have been unable to 

 find any determination of the latent heat of fusion of fat ; beeswax is given 



It may be asked why, if such a complete system of chemical heat regulation 

 exist in the amesthetised animal, the temperature falls so continuously in an 

 animal exposed even to room temperature. The answer must lie in the 

 fact that though the mechanism is in order the response of the heat- 

 producing organs is not efficient. That this is so is borne out by the fact 

 that the extra O2 consumption produced by a fall of the skin temperature 

 of 1° C. varies from about 6 to 30 per cent, of the (calculated) basal 



as 22. 



X 



K 



200 



* 



X 



X 



100 



100 



A 











34 



36 



32 



35 



Fig. 5.— Cat, 1650 giro. As fig. 2. 



