Biography of Berzelius. 195 



cognise in a substance obtained in the course of an investi- 

 gation, a hitherto unknown element. This requires such a 

 perfect knowledge of the known elements as can only be ac- 

 quired by many laborious investigations and long expe- 

 rience. For this reason new elementary bodies are not 

 easily discovered by young chemists, not even by those of 

 high talent. The discovery of cerium, which Berzelius 

 made in his twenty-third year, shews therefore the great 

 and rare sagacity which he displayed even in his first in- 

 vestigations. 



Klaproth investigated the tungsten of Bastnas simulta- 

 neously with Berzelius and Hisinger, and declared that the 

 oxide which it contained in combination with silica was new. 

 But he overlooked its metallic nature, and, although he ob- 

 tained it of a reddish-yellow colour, regarded it as an earth, 

 which he called Ochroit earth. The investigation of Berzelius 

 and Hisinger was evidently carried out with more precaution 

 than that of Klaproth. Not only did the latter overlook the 

 partial solubility of the oxide in solutions of alkaline carbo- 

 nates, he did not even remark the disengagement of chlorine 

 on treating the ignited oxide with hydrochloric acid. It was 

 not until afterwards, when, for the second time, he made 

 known his investigations upon cerite in the fourth volume of 

 his " Beitra^e zur chemischen Kenniniss der Mineral Kor- 

 per," which did not appear until 1807, that he mentioned 

 the evolution of oxy-muriatic gas on treating the ignited 

 oxide with muriatic acid, still, however, without attaching to 

 the fact any great weight. Berzelius and Hisinger, on the 

 contrary, justly considered this of very special importance, as 

 unequivocally pointing out two different stages of oxidation, 

 at that time one of the principal means of distinguishing be- 

 tween metallic oxides and earths, which were then regarded 

 as simple bodies. Gehlen also directed attention to this point 

 in a remark upon the paper of Berzelius and Hisinger. Fur- 

 ther, he was fortunate enough to accomplish, with the aid of 

 Hjelm, the reduction of the oxide, and to obtain the metal in 

 an isolated, although not in a melted state. 



When Berzelius subsequently undertook the determination 

 of the equivalent weights of almost all the elementary bodies 



