10 Dr. Thomson's Answer [Jan. 



constituents of this salt, exactly as I have stated them, were 

 communicated to me by Dr. Prout before I left London in 

 1817. Berzelius had analyzed it at least as early; for he gives 

 its constituents in the tables attached to the third volume of his 

 Larbok i Kemien, published in 1818, which was translated into 

 French, and published by hinaself in 1819, under the title of 

 Essai sin- la T/ieorie (hs Proportions Chimiqiies, a book which 

 Dr. Ure has no doubt seen. It requires no httle command of 

 face to claim coolly as a discovery made by himself in 1822 an 

 analysis published by Berzelius in 1818. I never dreamed that 

 I was claiming as ray own exclusively all the analyses which I 

 have given in my late work. It is indeed true that two-thirds of 

 them at least are^ new, and that all of them were repeated in my 

 laboratory either by myself or my pupils, under my superinten- 

 dence and direction. This was the object, and the sole object 

 in view. Historical details and claims of priority I left for my 

 System ofChemistry, in the various editions of which they demand 

 and obtain a place." I was not aware that Dr. Ure had favoured 

 the public with an analysis of this salt, and had I known it, I 

 should have seen no propriety in noticing his posthumous 

 labours. 



7. The assertion that my experiments on the atomic weight 

 of hme, and the specific gravity of carbonic acid gas, are ficti- 

 tious, merits no answer, and shall receive none. I had occasion, 

 during my long and laborious researches on these important 

 subjects, to examine the validity of some previous experiments 

 of the worthy author of the review, by which he assured us that 

 the carbonates could be analyzed with the utmost expedition 

 and accuracy. I made no allusion to these experiments in my 

 late work, because I take no pleasure in exposing the mistakes 

 of others. Even here I should have been silent on the subject, 

 had the Doctor left me any alternative. I have not a doubt that 

 fictitious statements upon this subject have been palmed upon 

 the public. It was very natural for the author of the review, 

 conscious of the existence of his own previous statements, to 

 which he durst not venture to allude, to turn up his nose at my 

 researches; which he good-naturedly allows to be accurate as to 

 the conclusions, but impossible as to the premises. There is a 

 proverbial allusion to this very common mode of conduct too 

 indehcate to be quoted here ; but well worthy of the Doctor's 

 serious consideration, that he may know by it how to regulate 

 his conduct hereafter. 



8. I beg leave to present my reader with another quotation 

 from the review. " Now we afiirm that this experiment, from 

 which he deduces the atomic weight of chromium, was never 

 made, for the result is impossible. Ammonia does not -precipitate 

 oxide of chromium from the above green solution in tartaric acid." 



The method here alluded to by tiie reviewer, and pro- 



