LORD BROUGHAM S APPENDIX. 479 



of the two gases so often quoted. Such is, in short, with more 

 or less distinctness, the conclusion that the three learned men 

 presented. 



It now remains to consider Blagden s declaration, from 

 which Lavoisier might have learned the theory of Cavendish, 

 even before he had made his principal experiment. Blagden 

 inserted this declaration in Cavendish s own Memoir ; * it was 

 published in the Philosophical Transactions, and it does not 

 appear that Lavoisier ever contradicted it, however irrecon 

 cilable it was with his own recital. 



Notwithstanding all Blagden s susceptible jealousy in favour 

 of the priority of Cavendish, there has not been on his part a 

 single allusion from which one might deduce that, before pub 

 lishing his own, Watt had heard of his competitor s theory. 



We will not be so positive relative to the question of Cav 

 endish having had some knowledge of Watt s labours, before 

 arranging the conclusions in his own Memoir. To maintain 

 that Cavendish was not ignorant of Watt s conclusions, we 

 might remark how very improbable it was that neither Blag- 

 den nor any one else to whom those conclusions were known, 

 had ever mentioned them to him. It might also be said that 

 Blagden, even in those portions of the Memoir that were writ 

 ten in his own hand, and intended to claim the priority for 

 Cavendish against Lavoisier, nowhere affirms that the theory 

 of Cavendish was conceived before the month of April, 1783, 

 although in another addition to his friend s original Memoir 

 there is a quotation relative to Watt s theory. 



Since the question as to the epoch when Cavendish drew 

 conclusions from his experiments, is enveloped in great ob 

 scurity, it may be of some utility to inquire what were this 



* A letter to Professor Orel], in which Blagden gave a detailed ac 

 count of the discovery, appeared in the Annalen of 1786. It is 

 remarkable that in this letter, Blagden says that he communicated 

 to Lavoisier the opinions of Cavendish and of Watt, and that this lat 

 ter name figures here for the first time in the confidential verbal 

 recitals of the Secretary of the Eoyal Society. (Note by Mr. Whtt,jun. \ 



