CHAPTER IL 



OF THE PROCESSES OF OEGANIC CALORIFICATION. 



IF we must consider the chemical reactions of nutrition as the 

 principal source of organic heat, if this heat is a function of 

 nutrition, it must augment or decrease according as the exchange, 

 the molecular mutations, are made with more or less activity. 

 Now, every organic functionment has always as its effect, or 

 rather cause, an acceleration of the double nutritive movement 

 of assimilation and disassimilation ; consequently the local tem- 

 perature of each organ must incessantly vary. In effect, this 

 inductive conclusion is confirmed by observation ; for it is a 

 general law that every organ grows warm while accomplishing 

 its special function, to grow cold afterwards in the intervals of 

 repose. 



This fact can be proved, either by taking directly the tem- 

 perature of the organs, by the help of thermo-electric needles, or 

 by comparing the temperature of the blood which enters an 

 organ with that of the blood which issues from it. This experi- 

 ment is practicable, for example, in the arteries and the veins of the 

 glands. It has been made in the kidneys, the salivary glands, 

 and also in the afferent and efferent vessels of the liver. It has 

 thus been proved that the liver is the warmest organ in the 

 economy, that its efferent veins are warmer than its afferent 

 veins ; that in glands with intermittent functionment, like the 



O G 



