Chem ical Ph ilosophy . 9 3 



tides of matter. Boerhaave was one of the first 

 distinguished philosophers who taught, in opposi- 

 tion to Newton and others, that it was a distinct 

 substance. This doctripe was soon afterwards em- 

 braced by many others, and has been since gene- 

 rally received. Those who considered heat as a 

 mere property of matter, were at no' small diffi- 

 culty to account for cold^ which Boerhaave, and 

 those who followed him, supposed to consist 

 merely in the absence of heat. Some, in order to 

 avoid this difficulty, supposed cold to arise from 

 the presence and operation of frigorific particles. 

 MuscHENBROECK, a Celebrated Dutch philosopher, 

 was among the last of those who distinguished 

 themselves as the advocates of this opinion. 



After Boerhaave, the most eminent defenders 

 of his leading doctrine with respect to heat were 

 Dr. Crawford, Dr. Black, Mr. Magellan, 

 and Dr. Irvine, of Great-Britain, Mr. Kirwan, 

 of Ireland, Messrs. Lavoisier and De la Place, 

 of France, and Messrs. De Luc, De Saussure, 

 and PicTET, of Geneva. It would be inconsistent 

 with our limits to attempt even a sketch of the ex- 

 periments and discoveries made by these celebrated 

 philospphers. Among the most important of them 

 we may reckon the doctrine respecting latent heaty 

 before mentioned as having been published by 

 Dr. Black, in 1757, which doubtless led the way 

 to most of the subsequent discoveries in this part of 

 chemistry, and in a great measure changed the 

 face of the science. The invaluable instruction 

 which it affi^rds respecting combustion^ Jluiditij, eva- 

 poration, Sic. is well known. The facts brought 

 to light concerning specific heat, or the diffi:?rent 

 capacities of bodies to imbibe and retain this sub- 

 stance, first by Professor Wilcke, of Srockholm, 

 and afterwards, in succession, by Drs. Black, 

 JrvinE, and Crawford, and by Messrs. Kirwan, 



