WATT, 49 



curred to any one else.* It is to be noted, too, that 

 in 1784 Mr. Cavendish, after his celebrated experiment, 

 had not attained by any means so clear a notion of the 

 true doctrine as Mr. Watt explains in those previous 

 letters.f I examined minutely the whole of this sub- 

 ject eight years ago, at the request of my distinguished 

 colleague M. Arago, then engaged in preparing his 

 ' Eloge' of Mr. Watt, who had also been our fellow- 

 member of the Institute. The reader will find my 

 statement of the evidence annexed to this account. But 

 I cannot easily suppose that M. Arago ever intended, 

 and I know that I never myself intended, to insinuate 

 in the slightest degree a suspicion of Mr. Cavendish's 

 having borrowed from Mr. Watt. He had, in all pro- 

 bability, been led to the same conclusion by his own 

 researches, ignorant of Mr. Watt's speculations, which 

 were a little earlier in point of time, just as Priestley 

 when claiming, and justly claiming, the important dis- 

 covery of oxygen (called by him, in accordance with 

 the doctrine of Stahl, " dephlogisticated air"), never 

 denied that Scheele also made the same discovery, 

 (calling it " empyreal air"), without being aware of 

 another having preceded him. Priestley, of course, 

 treated the discreditable proceedings of Lavoisier in 

 respect to this gas very differently, and so must all 

 impartial men. 



It must on no account be supposed that Watt can- 

 not be considered as having discovered the composition 

 of water, merely because he made no new experiments 

 of particular moment, like Cavendish, to ascertain that 

 capital point. No one refuses to Newton the discovery 

 of gravitation as the controlling and directing power 

 of the solar system; and yet he made not one of those 

 observations upon which his theory rests; nay, he 

 threw it aside for sixteen years when the erroneous 



* Letters to Gilbert Hamilton of Glasgow, Fry of Bristol, Smeaton, 

 De Luc all dated March and April, 1783. 



t See Life of Cavendish for further particulars and explanations. 

 E 



