308 LAVOISIER. 



with the terms of chemistry, I said plombe rouge, which 

 was not understood till Mr. Macquer said I must mean 

 minium. M. Scheele's discovery was certainly inde- 

 pendent of mine, though, I believe, not made quite so 

 early." 



It is very important here to remark that M. Lavoisier's 

 surprise was expressed at finding that minium had 

 yielded this new air by reduction. He himself had 

 made the experiment with minium, as we have seen, 

 and only could detect fixed air as the produce ; whence 

 his erroneous inference that a metallic calx is composed 

 of the metal united with fixed air. It was not till six 

 months after this discovery of Dr. Priestley, and full 

 four months after his expression of surprise, that he 

 made the experiments which he many years afterwards 

 thought it not unbecoming to affirm, had led him to the 

 discovery about the same time with Priestley. I will 

 venture to assert that no one, however little conversant 

 with the rules of probability, or accustomed to weigh 

 testimony, can hesitate a moment in drawing the con- 

 clusion, that M. Lavoisier never at any time made this 

 discovery ; that he intruded himself into the history of 

 it, knowing that Priestley was its sole author ; and that, 

 in all likelihood, he covered over to himself this un- 

 worthy proceeding, so lamentable in the conduct of a 

 truly great man, by the notion that he differed with 

 Priestley in his theory of the gas the one conceiving 

 it to be a peculiar air deprived of phlogiston, and cap- 

 able of taking it from inflammable bodies ; the other 

 holding it to be air which unites to inflammable bodies, 

 and precipitates its heat and light in forming the union. 

 But all must admit that the air was a newly discovered 

 substance, a gas wholly different from all other gases 

 formerly known ; and that therefore, whatever might 

 be the theory, the question of fact regarded the bring- 

 ing this new substance to light. No self-deception, 

 therefore, can vindicate M. Lavoisier for either the 

 statement in his Memoir, suppressing all mention of 



