214 Historical Review of Experiments 



the supposition that heat is nothing but a vibratory 

 motion taking place among the particles of bodies. 



A bell, on being struck, immediately gives forth a 

 sound, and the oscillations of the air produced by these 

 vibrations forthwith cause a quivering motion in those 

 bodies with which they come in contact. On the other 

 hand, a sponge filled with water cannot give off its 

 moisture to the bodies in its vicinity for any length of 

 time without itself losing moisture. 



A very illustrious philosopher, for whom I have al- 

 ways entertained the greatest respect, and whom, more- 

 over, I have the good fortune to count among my most 

 intimate friends, M. Bertholet, has, in his admirable 

 Essai de Statique Chimique, attempted to explain the re- 

 sults of this investigation, and to reconcile them with 

 that theory of heat which is founded upon the hypothe- 

 sis of caloric. 



If a man as learned, as honest, as worthy, and as re- 

 nowned as is M. Bertholet, spares no pains in opposing 

 the errors of a natural philosopher or chemist, one can- 

 not and dare not keep silence unless he wishes to ac- 

 knowledge himself vanquished. If, however, one can 

 produce proofs a fortunate thing for all those who 

 find themselves driven to similar self-vindication that 

 the objections of M. Bertholet have no foundation, he 

 has done very much towards establishing beyond doubt 

 the opinions and facts in question. 



I will now endeavour to answer the objections which 

 M. Bertholet has offered to my explanation of the 

 above-mentioned experiments ; and, that the reader 

 may be in a position to give to these objections their 

 just value, I will insert them here in the writer's own 

 words. 



