238 LAVOISIER. 



importance in which M. Lavoisier was engaged. For we 

 may pass over his experiments on the use of alcohol in 

 the analysis of mineral waters, as he admits that the 

 subject was familiar to chemists, having been treated at 

 length by Macquer. It may, however, be observed in 

 passing, that he claims as a discovery the proposition 

 that alcohol attacks salts differently when mixed with 

 different proportions of water; and also, that nothing 

 can be more crude than his notions of the connexions 

 between the salts and the mineral kingdom for a large 

 portion of his Memoir is devoted to prove that there 

 can only be three mineral alkalis, soda, calcareous earth, 

 and what he calls the base of Epsom salts, which is 

 magnesia, and two mineral acids, the vitriolic and muri- 

 atic propositions as wide of the truth as possible, and, 

 apparently, chiefly recommended to him by their shew- 

 ing that the experiments with alcohol, which he had made 

 with those substances, exhausted the subject of mineral 

 waters. 



But the next important inquiry of this eminent 

 chemist related to the action of heat on the diamond, 

 or, as he very inaccurately termed it, the destruction of 

 the diamond by fire. These experiments were performed 

 with great care, and without any regard to expense; 

 to which purpose a public-spirited jeweller also contri- 

 buted largely. They were performed partly by fire, partly 

 by the great lens of Tschirnausen belonging to the Aca- 

 demy. The Memoir is in the volume for 1772, Part II., 

 published in 1776; but the experiments were not all 

 performed till late in 1 773, and the Memoir was probably 

 read in 1774. It was found that some carbonaceous 

 effervescence (as he describes it) could be observed when 



