Manchester Memoirs, Vol. Ivii. (191 3), No. 10. 39 



The famous controversy concerning the composition 

 of water between Watt and Priestley is referred to in one 

 of the sentences of this letter. Watt showed himself the 

 better reasoner, whereas Priestley was the greater experi- 

 mentator. It is significant that in the same letter Lavoisier's 

 name is mentioned. I think the comparison between 

 Watt's work and Priestley's can be made with equal 

 justice with regard to Lavoisier and Priestley. I shall, 

 however, have occasion to discuss Lavoisier's work later 

 on, and will therefore proceed to the connection of 

 Priestley with another man. 



Joiiah Wedgwood was a frequent guest of the Lunar 

 Society, but Priestley had already been on friendly terms 

 with him before going to Birmingham. ^^ 



Amongst his autographs in my possession there is one 

 which I reproduce on PL IX. This is the circular 

 which Wedgwood sent to his customers announcing 

 that he had taken his son into partnership. Wedg- 

 wood was not only an admirer of Priestley, but also a 

 strenuous helper in supplying him with his excellent 

 earthenware materials, which were then, as for many years 

 after, highly valued for scientific research work.'*^ In return 

 for his help, Priestley straightway communicated to him 

 all his discoveries. This gave great satisfaction to Wedg- 

 wood, who was himself as prominent in science as in 

 artistic handicraft. Among my letters is one addressed to 

 Wedgwood and endorsed by the latter : — 



May, 1785. 

 Dear Sir, 



About the time that this comes to hand I hope 

 you will receive three copies of my paper of experi- 



*^ See 'Life of Josiah Wedgwood,' by E. Weteyard. London, 

 1865-66, vol. i., p. 391. 



*■* See 'Life,' vol. xi., p. 557 ; also Prieslley's 'Memoirs.' Cent, ed., 

 p. 60. 



