Biography of Berzelius. 13 



assumed that fluoric acid was an oxygen acid, and that it con- 

 tained a radical, combined with two atoms of oxygen, as he 

 had previously done in the case of hydrochloric acid. But in 

 the same year that he gave up his study of fluorine compounds, 

 viz., in 1825, he observed in the first part of the third German 

 edition of his " Lehrbuch," that it was more probable that 

 fluoric acid, like hydrochloric acid, was a hydrogen acid ; and 

 he described all the fluorine compounds according to this view. 



Together with these comprehensive researches, Berzelius 

 published a number of less extensive ones. They all origi- 

 nated in his meeting with a number of doubtful statements 

 while editing his " Lehrbuch,'' in reference to which he im- 

 mediately instituted experiments in his laboratory, for the 

 purpose of quickly deciding upon them. From among these I 

 will here mention only the research upon chloride of lime, 

 which was formerly regarded, according to Gay-Lussac, as a 

 compound of chlorine with lime, and the chlorides of potash 

 and soda were likewise regarded as similar in composition. 

 Berzelius, on the contrary, directly after adopting the view of 

 the elementary nature of chlorine, declared these bleaching 

 compounds to be mixtures of metallic chlorides with salts, 

 containing an oxide of chlorine as an acid. He was of opin- 

 ion, as he did not closely examine the subject, that the acid 

 was chlorous acid, until the researches of Balard proved that 

 it was hypochlorous acid. 



Berzelius proved, that all the other explanations of the 

 composition of the bleaching compounds were incorrect, by 

 shewing that these contained an oxide of chlorine. He dis- 

 solved, in a solution of carbonate of potash, as much chloride 

 of potassium as it would take up, and passed chlorine through 

 the liquid without saturating it. After a few minutes chlo- 

 ride of potassium was precipitated, which contained no chlo- 

 rate of potash, or scarcely any ; the liquid had acquired the 

 power of bleaching. When the liquid was separated from 

 the precipitated chloride of potassium, and perfectly saturat- 

 ed with chlorine, chlorate of potash was precipitated, con- 

 taining scarcely any chloride of potassium. Consequently, 

 during the first action of the chlorine, chloride of potassium 

 must have been formed from potash, the oxygen of which 



