Biography of Berzelius. 7 



similar view possibly correct, although not exactly more pro- 

 bable than the old one, after the discovery of iodine, openly 

 declared themselves, with Vauquelin and all the other French 

 chemists, in favour of the new doctrine ; and the famous 

 paper of Gay-Lussac upon iodine, which appeared in 1813, 

 is written in this spirit. 



Berzelius alone, who from the first had disputed the hypo- 

 thesis of Davy, continued to defend the old doctrine, even 

 after the discovery of iodine. He did this especially in a 

 paper which first appeared in Gilbert's Annalen for 1815. He 

 there endeavoured, with a profound sagacity which cannot 

 but be highly admired by every one, even on reading the paper 

 after the lapse of so long a time, to prove the truth of the 

 doctrine of the compound nature of chlorine. He directed 

 attention to the remarkable phenomenon that the constitu- 

 ents of chloride of nitrogen, which are united only by a very 

 feeble affinity, separate with such an energetic evolution of 

 heat as is never observed except in chemical combinations. 

 But above all, he pointed out the analogy which existed be- 

 tween muriates, which, according to the new theory, in the 

 anhydrous state contain no oxygen, and the sulphates, phos- 

 phates, and other salts, which are indisputably compounds of 

 oxygen acids with oxygen bases, and in which the presence 

 of oxygen may be readily detected. 



The great authority of Berzelius, and the soundness with 

 which he carried out his refutation of all the evidence brought 

 forward in favour of the new theory, were the reasons why 

 many chemists, especially in Germany, did not adopt Davy^s 

 view of the nature of chlorine. 



The immediate cause of Berzelius undertaking the inves- 

 tigation of the cyanides of iron was evident, viz., he expected 

 to find in them a more compound radical (united with oxy- 

 gen forming an acid) associated with an oxygen base, and 

 similar to that which he assumed to exist in muriates. It 

 cannot be disputed that to some extent he doubted the ac- 

 curacy of Gay-Lussac' s experiments on cyanogen. Then, 

 as the salts of the ferrocyanic radicals resemble so closely in 

 their characters the ordinary oxygenous salts, and especially 

 as several metallic cyanides, such as cyanide of mercury 



