930 MATHEMATICAL AND PHYSICAL SCIENCE. 
Argument it prudent to delay the publication until he should 
[Diss. VI. 
his numerous animadversions on other parts of the 
ae ‘ have considered it [the theory of the composition same papers, he gives (as I have pointed out in the 
haviour, Of water] more maturely, and have made some ex- note to art, 318) free expression to the sensitive- 
ness which he felt lest Dr Black should derive any 
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 
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 Argument 
Watt cannot be maintained without impeaching the ‘fm the 
honour and integrity of his rival, and showing that he cr caren. 
stooped to subterfuge in order to appropriate to him- dish. 
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- 
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 others, 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, _ (599.) 
the former having been born only three years earlier. a ol 
But I doubt whether these two men, so congenial in periments 
their studies, so different in almost every circum-on latent 
stance, whether of fortune or temperament, ever met, ®"4 specific 
They had this, however, in common, that they pub- pee 
tional experiments of his own influentially contzi- 
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 
nodisposition 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 ;”’? 
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 
lished their discoveries and observations with relue- 
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 whieh 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 
1 Robison’s Mechanical Philosophy, ii., 21. 
2 The article WaTER in the early editions of the Encyclopedia 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 Zncyclopadia 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 
Kdition, and a reference made to the article Chemistry where Cavendish received the credit of the discovery. 
i 
