132 



MATHEMATICAL AND PHYSICAL SCIENCE. 



[Diss. VI. 



Argument it prudent to delay the publication until he should 

 from have considered it [the theory of the composition 



haviour be ~ ^ water ] more m ature lv> and have made some ex- 

 periments to determine the proof or falsehood of it." 

 This, it must be owned, was not the language of a man 

 who had acquired that amount of conviction which 

 is needful, not to broach a theory, but to hold fast 

 by it against all opposition. With the caution which 

 formed part of his character, Watt was unwilling 

 to hazard his reputation by adhering to a doctrine 

 which appears at the time to have received no sup- 

 port from his scientific friends, especially Dr Black. 

 Having read the correspondence published by Mr 

 Muirhead, I cannot doubt that Watt, whatever his 

 private opinions might continue to be, would never 

 have urged his views on an unwilling public, but 

 would have finally suppressed the letter to Priestley, 

 had not the experiments and claims of Cavendish at 

 home, and of Lavoisier in France, reanimated all 

 his zeal for the assertion of his opinion. This in- 

 deed Watt ingenuously admits in the letter to Sir 

 Joseph Banks just cited, where he states that the 

 fact of similar theories having since been supported 

 by philosophers of first-rate abilities, removed his 

 second objection to publication. As the suppression 

 of his paper would have relieved Watt of all the re- 

 sponsibility of error, it seems impossible to allow him 

 the advantage of which that suppression deprived 

 him of anticipating the date of his matured convic- 

 tion; and to this conviction we have his own evidence 

 that Cavendish's publication as well as certain addi- 

 tional experiments of his own influentially contri- 

 buted. Watt, in after life, may be said to have tacitly 

 relinquished to Cavendish the honour which, in the 

 first irritation of the conflict of their claims, he showed 

 no disposition to do ; it is, therefore, reasonable to infer 

 that, on reflection, he saw good reasons for doing so. 

 By this I mean that he suffered judgment to be passed 

 in favour of Cavendish's claim in the writings of many 

 of his eminent contemporaries, without attempting 

 publicly to correct the all but universal impression 

 which they made. In one instance, he almost ho- 

 mologated this adverse judgment : In the article on 

 Steam, written by Robison, and revised by Watt in his 

 last years and after Cavendish's death, this passage 

 appears, " This is fully evinced by the great disco- 

 very of Mr Cavendish of the composition of water ;" 1 

 from which it must be concluded, first, that Robison, 

 the intimate friend of Watt, and the almost chival- 

 rous defender of his fame, believed Cavendish to 

 be the true discoverer ; 2 secondly, that Watt, in 

 commenting on this article in 1814, permitted the 

 fact to be thus transmitted to posterity. For, in 





his numerous animadversions on other parts of the 

 same papers, he gives (as I have pointed out in the 

 note to art. 318) free expression to the sensitive- 

 ness which he felt lest Dr Black should derive any 

 credit to which he was not entitled in connection with 

 the steam-engine, but he suffers the passage just 

 quoted to pass without remark. Such being the 

 case, and waiving all purely chemical discussion, 

 I am of opinion that Watt's friends should have 

 left the matter as he was content to leave it. 



With reference to the argument from Cavendish's (598.) 

 character, I would remark that whilst the claim of Argumen 

 Watt cannot be maintained without impeaching the f ni ' 

 honour and integrity of his rival, and showing that he O f <javen- 

 stooped to subterfuge in order to appropriate to him- dish, 

 self a discovery due to another it would yet be diffi- 

 cult to find in the whole range of scientific history 

 (without excepting the venerable name of Newton), an 

 individual so devoted to knowledge for its own sake, 

 so indifferent to the rewards of discovery, so averse to 

 the publication of what he felt to be important, and 

 knew to be original, so insensible to the voice of 

 praise when applied to himself, so ardent in acquaint- 

 ing himself with the labours of oilers, and so liberal 

 in assisting them. Such a man was Cavendish ; and 

 that he should stoop even to the common artifices of 

 little minds for exalting his own reputation at the ex- 

 pense of others, would itself be incredible ; how much 

 more the insinuation (grounded solely on alleged cir- 

 cumstantial evidence) that in doing so he disregarded 

 the plainest dictates of honour and justice. 



Black and Cavendish were nearly contemporaries, 

 the former having been born only three years earlier. 

 But I doubt whether these two men, so congenial in 

 their studies, so different in almost every circum- on latent 

 stance, whether of fortune or temperament, ever met. * nd 8 P eci 

 They had this, however, in common, that they pub- 

 lished their discoveries and observations with reluc- 

 tance, and were fastidious in the manner of doing so. 

 Black's experiments, both in chemistry and on heat, 

 preceded those of Cavendish, and with regard to the 

 latter subject (heat) it is probable that Cavendish 

 pursued investigations and made original experi- 

 ments, in which he had been unknowingly anticipated 

 by the Scotch professor. His researches on latent 

 and specific heat (though he did not employ these 

 terms) appear to have been subsequent to Black's, 

 but to have preceded those of Crawford and Wilcke ; 

 and it is not impossible that his was the earliest, or 

 one of the earliest, determinations of the amount of 

 heat absorbed in the conversion of water into steam, 

 for which he obtained various results between 923 

 and 982, a mean of which would be very near the 



(599. 



1 Robiflon's Mechanical Philosophy, ii., 21. 



2 The article WATER in the early editions of the Encyclopaedia Britannica has been quoted as the production of Robison, 

 of which there does not appear to exist any proof, whilst the probability, as shown in the text, lies all the other way. I learn 

 upon the best authority that the proprietors of this Encyclopaedia have no clue to the authorship of that article, and that it is 

 not included in the lists of Robison's known contributions. The part relating to the present question was expunged in the Fourth 

 Edition, and a reference made to the article Chemistry where Cavendish received the credit of the discovery. 



