48 LOEWENFELD, Contrilmtions to the History of Science. 



Lavoisier's experiments, referring to the measurement 

 of specific heat, which he worked together with Laplace, 

 are most significant. His experiments on the production 

 of respiration are also of great importance.^^ 



But Lavoisier's chief title to immortality rests, not so 

 much on his experimental work, as on the new and most 

 ingenious way in which he interpreted the experiments of 

 others. 



As already mentioned, the period of Priestley's best 

 experimental work was about 1771-1779. It is no mere 

 accident that Lavoisier's most important publications date 

 from approximately the same period. Lavoisier was the 

 first to see the true importance of the discovery of oxygen. 

 He saw that this gas had to be present in all processes in 

 which the chalx of a metal is formed from the metal 

 itself But he saw still more ; he saw clearly that the 

 explanation of this process which is accompanied by an 

 increase in weight was to be found in the simple chemical 

 addition of the weight of oxygen. These discoveries 

 took him still a step further. In following up all his 

 experiments exactly with a balance, Lavoisier found that, 

 whatever processes took place, the total weight of all the 

 chemical compounds acting in these processes was never 

 changed ; in other words, he found one of the two great 

 propositions which, so to speak, govern the way in which 

 we nowadays regard all processes in chemistry, namely, 

 the conservation of matter. All this, of course, was in part 

 exactly the opposite of the then still all-powerful theory 

 of phlogiston ; it therefore amounted to nothing less than 

 a revolution in chemistry. 



Most unfortunately, Lavoisier's life coincided with the 



^' A list of Lavoisier's publications is given in Grimaux's work, pp. 

 336 — 35S. His works have been edited under the care of the Minister of 

 Public Instruction in France. (Paris, 1846— 1S93.) The works of Priestley 

 have not yet been collected. 



