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 normaily. 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 
