S Mr. Colqiihoitn on the Life and Writings [Jan. 



pie of acidification. In his memoir BerthoUet shows that sul- 

 phuretted hydrogen gas, in which oxygen is not present, never- 

 theless performs all the functions of an acid: and surely it seems 

 reasonable that a doctrine opposed in toto by every one, should 

 not first be received as generally correct by him who alone had 

 discovered any just grounds for qualifying one of its leading 

 principles. Yet it is strange enough that this very man proved 

 eventually the first leading chemist who did admit the just doc- 

 trines of the new theory, and it seems stranger still that those 

 who held out longest against its truths, were also the first to 

 embrace and defend its errors. But so it was ; for Berthollet's 

 subsequent assertion, argimients, and numerous decisive experi- 

 ments, all proving oxygen not to constitute the sole principle of 

 acidification, fell for many a year unheeded on the ears and 

 understandings of men of science, until the united force of the 

 facts brought forward by Gay-Lussac, Thenard, and Ampere, 

 joined to the profoimd and admirable reasoning of Sir H. Davy, 

 at length established the accuracy of this limitation and qualifi- 

 cation of the principles laid down by Lavoisier. 



In another memoir of our chemist, on the Nature of the Vola- 

 tile Alkali, presented soon after to the Academy, he announced 

 a theory of his own upon the subject, which proceeded upon a 

 basis altogether erroneous. This essay was entrusted to Lavoi- 

 sier, to report upon its merits to the Academy, who, with disin- 

 terested tenderness for the honour of his antagonist, dissuaded 

 him from committing himself by the publication of his system ; 

 and Berthollet's conduct is not less to be admired for the assent 

 which he immediately yielded to the kindness and to the expe- 

 rience of his adviser. The memoir was not published. His 

 reputation was thus not publicly staked in support of any erro- 

 neous system ; and the stimulus which this very restraint gave 

 to the ardour of his researches, led him a few years afterwards to 

 one of his most elegant discoveries, that of the true nature of 

 the volatile alkali. It is impossible not to esteem so much gene- 

 rous co-operation on the part of these two illustrious chemists, 

 eager only for the advancement of science, and opposed as they 

 then were in many of their views ; yet the younger remaining as 

 free from distrust of his antagonist's advice, as the elder was 

 untainted by jealousy of his rival's reputation. 



In the subsequent experiments of BerthoUet on the decompo- 

 sition of nitre, phenomena presented themselves of so easy an 

 explanation on the antiphlogistic system, that it seems astonish- 

 ing how even prejudice itself could avoid the discovery of the 

 true composition of nitric acid. At this time, however, BerthoUet 

 was prepossessed against the truth, he clung to the old system, 

 and was rewarded accordingly : for the fine discovery that 

 oxygen and azote are the constituents of nitric acid was thereby 

 reserved for Cavendish. 



