WATT. 59 



appears not to have been in it when originally presented to 

 the Boyal Society; for the paper is apparently in Mr. 

 Cavendish's hand, and the paragraph, p. 134, 135, is not 

 found in it, but is added to it, and directed to be inserted 

 in that place. It is, moreover, not in Mr. Cavendish's 

 hand, but in Sir Charles Blagden's ; and, indeed, the latter 

 must have given him the information as to M. Lavoisier, 

 with whom it is not said that Mr. Cavendish had any 

 correspondence. The paper itself was read 15th January, 

 1784. The volume was published about six months after- 

 wards. 



M. Lavoisier's memoir (in the Mem. de 1' Academic des 

 Sciences for 1781) had been read partly in November and 

 December 1783, and additions were afterwards made to it. 

 It was published in 1784. It contained M. Lavoisier's 

 account of his experiments in June 1783, at which, he says, 

 Sir Charles Blagden was present; and it states that he 

 told M. Lavoisier of Mr. Cavendish having " already burnt 

 inflammable air in close vessels, and obtained a very sensible 

 quantity of water." But he, M. Lavoisier, says nothing 

 of Sir Charles Blagden having also mentioned Mr. Caven- 

 dish's conclusion from the experiment. He expressly states, 

 that the weight of the water was equal to that of the two 

 airs burnt, unless the heat and light which escape are pon- 

 derable, which he holds them not to be His account, there- 

 fore, is not reconcilable with Sir Charles Blagden's, and the 

 latter was most probably written as a contradiction of it, 

 after Mr. Cavendish's paper had been read, and when the 

 Memoires of the Academic were received in this country. 

 These Memoires were published in 1784, and could not, 

 certainly, have arrived when Mr. Cavendish's paper was 

 written, nor when it was read to the Royal Society 



But it is further to be remarked, that this passage of 

 Mr. Cavendish's paper in Sir Charles Blagden's hand- 

 writing, only mentions the experiments having been 

 communicated to Dr. Priestley ; they were made, says the 

 passage, in 1781, and communicated to Dr. Priestley ; it is 

 not said when, nor is it said that " the conclusions drawn 

 from them," and which Sir Charles Blagden says he com- 

 municated to M. Lavoisier in summer 1783, were ever com- 

 municated to Dr. Priestley ; and Dr. Priestley, in his paper 



