414 JOSEPH FOURIER. 



pletely verified, they have become laws of nature ; they 

 point out latent properties of caloric which could only be 

 discerned by the eye of the intellect. 



In the second question treated by Fourier, heat pre- 

 sents itself under a new form. There is more difficulty in 

 following its movements ; but the conclusions deducible 

 from the theory are also more general and more impor- 

 tant. 



Heat excited, concentrated into a certain point of a 

 solid body, communicates itself by way of conduction, 

 first to the particles nearest the heated point, then grad- 

 ually to all the regions of the body. Whence the problem 

 of which the following is the enunciation. 



By what routes, and with what velocities, is the prop- 

 agation of heat effected in bodies of different forms and 

 different natures subjected to certain initial conditions ? 



Fundamentally, the Academy of Sciences had already 

 proposed this problem as the subject of a prize as early 

 as the year 1736. Then the terms heat and caloric were 

 not in use ; it demanded the study of nature, and the 

 propagation OF FIRE ! The word fire, thrown thus into 

 the programme without any other explanation, gave rise 

 to a mistake of the most singular kind. The majority of 

 philosophers imagined that the question was to explain 

 in what way burning communicates itself, and increases 

 in a mass of combustible matter. Fifteen competitors 

 presented themselves ; three were crowned. 



This competition was productive of very meagre re- 

 sults. However, a singular combination of circumstances 

 and of proper names will render the recollection of it 

 lasting. 



Has not the public a right to be surprised upon read- 

 ing this Academic declaration : " the question affords no 



