1813.] M. Lavoisier. 91 



This essay, together with one of Cavendish on the same subject, 

 was the principal weapon employed to overturn the notion of 

 phlogiston advanced hy Mr. Kinvan. 



47. Description of a Method to increase the Effect of Heat 

 produced by Chemical Operations. Mem. Par. 1/S2. Published 

 in 17^5. This was by means of a steam of oxygen gas, a 

 method now too well known to require any description here. 

 Lavoisier describes the apparatus which he employed for the 

 purpose. 



48. Experiments on the Effect produced by a very high Tem- 

 perature on the Precious Stones. This consists in a detail of the 

 experiments made by means of the apparatus described in the 

 preceding paper. 



49. On the Union of Nitrous Gas with Common Air. This is 

 a eudiometrical paper, in which Lavoisier endeavours to calcu- 

 late from the mixture of nitrous gas and common air, and the 

 diminution or bulk, the quantity of oxygen gas contained in 

 common air. It is needless to observe that it is far inferior to 

 Mr. Cavendish's paper on the same subject. 



50. General Observations on the Solution of the Metals in 

 Acids. Mem. Par. 1782. Published in 1785. This is another 

 of tbe important dissertations by which Lavoisier established his 

 theory. He makes use of the decomposition of water with great 

 address and ingenuity. Indeed, I consider this as the most pro- 

 found of all Lavoisier's essays. He commits occasional mistakes, 

 but his reasoning on the whole is accurate. 



51. Experiments on the Precipitation of one Metal by another. 

 Mem. Par. 1782. Published in 1785. This is also a very 

 curious paper. He gives the true theory of these precipitations, 

 and endeavours from them to determine the proportion of oxygen 

 which unites with the different metals. Though all his results 

 are wrong, his table is still curious, as it exhibits the first attempt 

 to determine this very important point. 



52. On the Affinity of Oxygen for the different Bodies with 

 which it can unite. Mem. Par. 1782. Published in 1785. 

 This may be considered as a kind of treatise on affinity. Consi- 

 derable ingenuity is displayed in determining the affinity of 

 different bodies for oxygen; and though the table given is not 

 accurate, it constituted a valuable groundwork for succeeding 

 cx)h rimentcrs. 



53. On the Combination of Oxygen with Iron. Mem. Par. 

 1732. Published in 17#5. These elaborate experiments cannot 

 be considered as verj successful. 



54. On the Nature of the elastic Fluids disengaged during the 

 Fermentation of Animal Substances. Mem. Par. 1782. Pub- 

 lished in 17b;'). The chief gas obtained during his experiments 

 was carbonic acid gas. 



55. New Observations on the Increase of Weight which 



