NOTES TO BOOK XIV. 207 



I conceive that the discussion which the subject has 

 recently received, has left no doubt on the mind of any 

 one who has perused the documents, that Cavendish is 

 justly entitled to the honour of this discovery, which in his 

 own time was never contested. The publication of his 

 Journals of Experiments (Appendix to Mr. V. Harcourt's 

 Address) shows that he succeeded in establishing the point 

 in question in July 1781. His experiments are referred 

 to in an abstract of a paper of Priestley's, made by Dr. 

 Maty, the secretary of the Royal Society, in June 1783. 

 In June 1783, also, Dr. Blagden communicated the result 

 of Cavendish's experiments to Lavoisier, at Paris. Watt's 

 letter, containing his hypothesis that " water is composed 

 of dephlogisticated air and phlogiston deprived of part of 

 their latent or elementary heat ; and that phlogisticated 

 or pure air is composed of water deprived of its phlogiston 

 and united to elementary heat and light, 1 ' was not read till 

 Nov. 1783 ; and even if it could have suggested such an 

 experiment as Cavendish's, (which does not appear likely,) 

 is proved, by the dates, to have had no share in doing so. 



Mr. Cavendish's experiment was suggested by an ex- 

 periment in which Warltire, a lecturer on chemistry at 

 Birmingham, exploded a mixture of hydrogen and common 

 air in a close vessel, in order to determine whether heat 

 were ponderable. 



(H.) p. 170. Since I wrote the expression of hope in 

 the text, the period of Dalton's sojourn among us has ter- 

 minated. He died on the 27th of July, 1844, aged 78. 



His fellow-townsmen, the inhabitants of Manchester, 

 who had so long taken a pride in his residence among 

 them, soon after his death, came to a determination to 



