766 REPORT—-1890. 
had got from this preparation to Mr. Lavoisier, Mr. le Roy, and several other 
hilosophers, who honoured me with their notice in that city, and who, I dare say, 
cannot fail to recollect the circumstance.’ 
If any further evidence is required to prove that Lavoisier was not only not 
‘the true and first discoverer’ of oxygen, but that he has absolutely no claim to be 
regarded even as a later and independent discoverer, it is supplied by M. Berthelot 
himself. Not the least valuable portion of M. Berthelot’s book, as an historical 
work, is that which he devotes to the analysis of the thirteen laboratory journals 
of Lavoisier, which haye been deposited, by the pious care of M. de Chazelles, his 
heir, in the archives of the Institute. M. Berthelot has given us a synopsis of the 
contents of almost every page of these journals, with explanatory remarks and 
dates when these could be ascertained. As he well says, these journals ‘are of 
great interest because they inform us of Lavoisier’s methods of work and of the 
direction of his mind—I mean the successive steps in the evolution of his private 
thought.’ On the fly-leaf of the third journal is written, ‘du 25 mars, 1774, au 
18 fevrier, 1776.’ From p. 30 we glean that Lavoisier visited his friend M. Trudaine 
at Montigny about ten days after his conversation with Priestley, and repeated the 
latter’s experiments on the marine acid and alkaline airs (hydrochloric acid gas and 
ammonia). He is again at Montigny some time between the February 28 and 
the March 31, 1775, and repeats not only Priestley’s experiments on the decom- 
position of mercuric oxide, presumably by means of M. Trudaine’s famous burning 
glass, but also his observations on the character of the gas, The fly-leaf of the 
fourth journal informs us that it extends from February 13, 1776, to March 3, 1778. 
On p. 1 is an account of experiments made February 13 on ‘précipité per se de chez 
M. Baumé,’ in which the disengaged gas is spoken of as ‘ Pair déphlogistique de M. 
Prisley’ (sic). Such a phrase in a private notebook is absolutely inconsistent with 
the idea that at this time Lavoisier considered himself as an independent discoverer 
of the gas. How he came to regard himself as such we need not inquire. Nor is it 
necessary to occupy your time by any examination of the arguments by which M. 
Berthelot, with the skill of a practised advocate, would seem to identify himself 
with the case of his client. We would do him the justice of recognising the 
difficulty of his position. He seeks to discharge an obligation, of which the 
acknowledgement has been too long delayed. The Académie des Sciences a year 
ago awoke to the sense of its debt of gratitude to the memory of the man who had 
laboured so zealously for its honour, and even for its existence, during the stormy 
period of which France has just celebrated the centenary, and out of the éloge on 
Lavoisier which M. Berthelot, as Perpetual Secretary, was commissioned to deliver, 
has grown La Révolution Chimique. To write eulogy, however, is not necessarily 
to write history. We cannot but think that M. Berthelot has been hampered 
by his position, and that his opinion, or at least the free expression of it, has 
been fettered by the conditions under which he has written. We imagine we 
discern between the lines the consciousness that, to use Brougham’s phrase, the 
brightness of the illustrious career which he eulogises is dimmed with spots which 
a regard for historical truth will not permit him wholly to ignore. 
Two cardinal facts made the downfall of phlogiston complete—the discovery of 
oxygen and the determination of the compound nature of water. M. Berthelot’s 
contention is that not only did Lavoisier effect the overthrow, but he also discovered 
the facts. In other words, he has not only a claim to a participation in the 
discovery of oxygen, but he is also ‘the true and first discoverer’ of the non- 
elementary nature of water. This second claim is directly and explicitly stated. 
Although it is supported by a certain ingenuity of argument, we venture to think 
that we shall be able to show it has no greater foundation in reality than the first. 
Members of the British Association, who are at all familiar with its history, 
will recall the fact that this is not the first occasion on which the attempt to 
transfer ‘those laurels which both time and truth have fixed upon the brow of 
Cavendish’ has had to be resisted. At the Birmingham Meeting of 1839 the Rev. 
W. Vernon Harcourt, who then presided, devoted a large portion of his address to 
an able and eloquent vindication of Cavendish’s rights. The attack came then as 
now from the Perpetual Secretary of the French Academy, and the charges were 
