ee ee eee 
TRANSACTIONS OF SECTION B. TEL 
dephlogisticated air was nothing else than water deprived of its phlogiston; and, vice versd, 
that water was dephlogisticated air united with phlogiston. About the same time the news 
was brought to London that Mr. Watt, of Birmingham, had been induced by some observations 
to form a similar opinion. Soon after this I went to Paris, and in the company of Mr. 
Lavoisier and of some other members of the Royal Academy of Sciences I gave some account 
of these new experiments and of the opinions founded upon them. They replied that they 
had already heard something of these experiments, and particularly that Dr. Priestley had 
repeated them. They did not doubt that in such manner a considerable quantity of water 
might be obtained, but they felt convinced that it did not come near to the weight of the 
two species of air employed, on which account it was not to be regarded as water formed or 
produced out of the two kinds of air, but was already contained in and united with the airs, 
and deposited in their combustion. This opinion was held by Mr. Lavoisier, as well as by the 
_ rest of the gentlemen who conferred on the subject ; but, as the experiment itself appeared to 
them very remarkable in all points of view, they unanimously requested Mr. Lavoisier, who 
possessed all the necessary preparations, to repeat the experiment, on a somewhat larger scale, 
as early as possible. This desire he complied with on the 24th June, 1783 (as he relates in the 
latest volume of the Paris memoirs). From Mr. Lavoisier’s own account of his experiment, 
it sufficiently appears that at that period he had not yet formed the opinion that water was 
composed of dephlogisticated and inflammable airs, for he expected that a sort of acid would 
be produced by their union. In general, Mr. Lavoisier cannot be convicted of having 
advanced anything contrary to truth; but it can still less be denied that he concealed a part 
of the truth ; for he should have acknowledged that I had, some days before, apprised him of 
Mr. Cavendish’s experiments, instead of which the expression ‘il nous apprit’ gives rise to 
the idea that I had not informed him earlier than that very day. In like manner Mr. Lavoisier 
has passed over a very remarkable circumstance, namely, that the experiment was made in 
consequence of what I had informed him of. He should likewise have stated in his publica- 
tion not only that Mr. Cavendish had obtained ‘une quantité d’eau trés sensible,’ but that 
the water was equal to the weight of the two airs added together. Moreover, he should have 
added that I had made him acquainted with Messrs. Cavendish and Watt’s conclusions, 
namely, that water, and not an acid, or any other substance, arose from the combustion of the 
inflammable and dephlogisticated airs. But those conclusions opened the way to Mr. Lavoisier’s 
present theory, which perfectly agrees with that of Mr. Cavendish, only that Mr. Lavoisier 
accommodates it to his old theory, which banishes phlogiston.... The course of all this 
history will clearly convince you that Mr. Lavoisier (instead of being led to the discovery 
by following up the experiments which he and Mr. Bucquet had commenced in 1777) was 
induced to institute again such experiments, solely by the account he received from me, and 
of our English experiments , and that he really discovered nothing but what had before been 
pointed out to him to have been previously made out and demonstrated in England. 
To this letter, reflecting so gravely on his honour and integrity, Lavoisier made 
no reply. Nor did Laplace, Le Roi, Vandermonde, or any one of the Academicians 
concerned vouchsafe any explanation. De non apparentibus et de non existentibus 
eadem ratio. No explanation appeared, because none was possible. M. Berthelot 
ignores this letter, which is the more remarkable, since reference is made to it in 
more than one of the publications which he tells us he has consulted in the pre- 
paration of his account of the Water Controversy. If he knew of it he must regard 
it either as unworthy of an answer or as unanswerable. 
It would be heaping Ossa on Pelion to adduce further evidence from letters of 
the time of what Lavoisier’s contemporaries thought of his claims. De mortuis 
nil nist bonum. I would much more willingly have dwelt upon the virtues of 
Lavoisier, and have let his faults lie gently on him; but I have felt it incumbent 
on me on this occasion to make some public answer to M. Berthelot’s book, and in 
no place could that answer be more fittingly given than in this town which saw the 
dawn of that work out of which these grand discoveries arose. It may be that much 
of what I have had to say is as a twice-told tale to many of you. I trust I need 
make no apology on that account. The honour of our ancestors is in our keeping, 
and we should be unworthy of our heritage and false to our trust if we were slow 
to resent or slack to repel any attempt to rob them of that glory which is their 
just right and our proud boast. 
The following Reports and Papers were read :— 
1. Report of the Committee on recent Inquiries into the History of Chemistry. 
[A Report will be presented at the next meeting of the Association.] 
