HEAT AND LIFE. 



THE full solution of the question of heat and life could 

 only be reached by simultaneous concurrence of physics, 

 chemistry, and biology. Ancient physiology treated of ani- 

 mal heat empirically, but was unable to explain its origin. 

 That result required the discoveries of Lavoisier and the 

 more modern researches of thermo-chemistry. After re- 

 vealing the source of that heat, it was important to show 

 how it was disposed of ; and this is taught us by thermo- 

 dynamics. And, in conclusion, only the most delicate 

 physiological experiments could settle the modifications 

 that take place in living beings, when subjected to the in- 

 fluence of a temperature either above or below that they 

 possess normally. Medicine and hygiene already benefit by 

 the indications yielded by pure science upon this subject. 

 It is admitted that the study of the variations of animal 

 heat in diseases is of the highest consequence for their 

 comprehension, and that both diagnosis and prognosis re- 

 ceive unexpected light from it. 



An inquiry into calorific phenomena, undertaken from 

 various separate and independent points of view, for the 

 solution of questions that seemed at first sight to have no 

 mutual connection whatever, has thus obtained a body of 

 truths which enter into combination almost of their own 

 accord at the present time, and are found to contain the 

 secret of a great problem in natural philosophy. A minute 



