1 1 Rev. W. V. Harcourt on Lord Brougham's statements 



6" 



feet good faith in the whole affair, I never having supposed 

 that he borrowed from Mr. \\ att, though M. Arago, Pro- 

 fessor Robison and Sir H. Davy, as well as myself, have 

 always thought that Mr. Watt had, unknown to him, antici- 

 pated his great discovery." 



Of the deceased philosophers, whose names are here pressed 

 into this service, I shall presently have occasion to speak ; but 

 let me first venture to answer for M. Arago, that if he has 

 " read the fac-similes" of Cavendish's notes, you will not find 

 him at the same loss as yourself to discover the inferences of 

 the experimental philosopher in the steps of his investigation', 

 he will not join you in propounding, " that in all Cavendish's 

 diaries and notes of his experiments, not an intimation occurs 

 of the composition of water having been inferred by him earlier 

 than Mr. Watt's paper of spring 1783." 



Those celebrated experiments of 1781, which pass with 

 chemists for a model of a well-combined train of analytical 

 and synthetical research, you imagine to have been without 

 object or inference, till an imperfect attempt to repeat them 

 had the good luck to be reasoned upon by Watt in 1783. 

 You appear to think that the manner in which the great facts 

 of experimental philosophy are ascertained is by one man's 

 stumbling on the proofs, and another some time after hitting 

 on the conclusion. If it be so, I believe that you would have 

 been as capable of interpreting such experiments, once made, 

 as James Watt himself; and could you have been at hand 

 when Cavendish, in July 1781, completed the discovery of 

 those facts which prove the composition of water, he need not 

 have waited so long to learn what to infer from them : I doubt 

 not but that you would at once have drawn the inference for 

 him, established the theory, and become for ever memorable as 

 the true discoverer ; you would, in your own amended phrase, 

 " unknown to him, have anticipated his great discovert/." 



But I own I do not suspect your w colleague" of these pecu- 

 liar views. Once satisfied that Cavendish spoke truth when 

 he said that all the experiments on this subject published in 

 his paper were made by him in the summer of 1781, he will 

 no longer doubt to whom the discovery of this important fact 

 is due ; once convinced that the experiments were communi- 

 cated to Priestley, and that the attempt to repeat them was 

 made in consequence of that communication; once aware 

 that the repetition was abortive because made with a wrong 

 gas, that neither the phlogiston nor the inflammable air of 

 Priestley and Watt were convertible terms for hydrogen, and 

 that their notions of the change of water into air and air 

 into water had no reference to that particular gas, but first to 



