LAVOISIER. 243 



We shall first give the words in which he couches his 

 claim. I quote from his ' Elemens de Chimie/ " Get air'' 

 (oxygen gas,) "nous avons decouvert presqu'en mme 

 terns, Dr. Priestley, M. Scheele et moi." 



Now I begin this statement by observing, that as to 

 the precise time of Dr. Priestley's discovery there is no 

 doubt ; no " presqu'en meme terns ;" it was the first day 

 of August, 1774. Scheele, without knowing of his dis- 

 covery, made the same the year after, 1775. So far then 

 the statement of Lavoisier is incorrect; Priestley and 

 Scheele did not discover oxygen, " presqu'en meme terns." 

 But we must proceed, and shall first of all examine in 

 what way M. Lavoisier preferred his claim. For that 

 would have rested upon a foundation somewhat more 

 plausible had he brought it forward early, and always 

 adhered to the same statement. But the reverse is the 

 fact. 



We must first observe that not a hint is dropped of 

 this claim in the paper upon calcination first presented 

 in 1774, and afterwards with additions in 1777. In 

 1775, at Easter, he read a paper on the nature of calci- 

 nation, which was "relu 8 August, 1778;" with what 

 additions is not stated. But the experiments which it con- 

 tains are of two classes; the one set he says were made 

 above a year before, or in spring 1774, and these throw no 

 new light at all on the subject ; the others were made, he 

 says, first in November, 1774, and more fully before other 

 persons, in the following spring. These experiments show 

 that the oxygen of the atmosphere is absorbed in calcina- 

 tion ; and this conclusion is stated ; but no claim whatever 

 is made to the discovery of oxygen gas, although if dis- 

 covered by him at all, it must have been in those experi- 



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