1-A Biography of Be rzelius. 



could only have combined with chlorine, giving rise to the 

 production of the bleaching compound. 



It had long been the wish of Berzelius to investigate the 

 rare metals accompanying platinum, the knowledge of which 

 had been left imperfect by the chemists who discovered them. 

 He was enabled to carry this into execution, when, after the 

 discovery of the large quantities of platinum in the Ural, he 

 received, through Herrn von Caucrin, a considerable quan- 

 tity of native platinum, as well as native Osmium -Iridium. 

 This circumstance led him into a very important investiga- 

 tion of the process for decomposing native platinum ores, by 

 means of which the rare metals accompanying platinum were 

 first properly made known. He studied the characters, de- 

 termined the atomic weights of Rhodium, Palladium, Iridium, 

 and Osmium, and prepared a [number of their compounds. 

 Owing to the great number of the oxides and chlorides of 

 these metals, and their great similarity to each other, this 

 investigation was very difficult ; and, as regarded osmium 

 and osmic acid, a very unpleasant one. But although Ber- 

 zelius himself declared that he had as it were given only the 

 first sketch of the history of these metals, still this re- 

 search, like all that came from his hands, was an extreme- 

 ly accurate, and to a certain extent, perfect one. 



The next investigation of Berzelius was in reference to a 

 new and peculiar earth, Thoria, which he had discovered in 

 a mineral from Brevig, in Norway. He had previously, on 

 examining the mineral near Fahlun, found an earthy sub- 

 stance in very small quantity, which he regarded, although 

 not with certainty, as a new earth, which he called Thoria ; 

 subsequently, however, he convinced himself that it was 

 phosphate of Yttria. Since the newly discovered earth re- 

 sembled, in some of its peculiar characters, alumina, he called 

 it likewise Thoria ; the mineral in which he had detected it, 

 Thorite, and the metal which he obtained from its volatile 

 chlorine compound, Thorium. Thoria belongs to a group 

 of earths which are very similar in their characters to zir- 

 conia, and of which Svanberg, Bergemann, and Sjogren have 

 recently discovered several. At first Berzelius assumed that 

 thoria contained only one atom of oxygen ; the experiments, 



