1819.] M. Stromeyer s new Details respecting Cadmium. 269 



Solutions of copper, Solutions of silver, 



protoxide of iron, manganese, 



acetate of lead, alumina, 



zinc, magnesia, 



cobalt, 



are not altered by these salts ; but they precipitate 



Peroxide of iron, yellow ; 

 Protonitrate of mercury ; 

 Subacetate of lead ; 

 titrate of tin, white. 



The acid alone precipitates only subacetate of lead. 



The properties pointed out are sufficient to distinguish this 

 acid from the benzoic and succinic as Scheele may have supposed 

 it to be ; and from the succinic acid alone, which Trommsdorf 

 took it for. As for the pyrotartaric acid announced by this last 

 chemist as one of the products of the calcination of mucic acid, 

 reagents have not been able to ascertain its existence ; while a 

 very small quantity of a soluble pyrotartraie mixed with a great 

 quantity of a pyromucate is demonstrated by the precipitate 

 which it forms with the sulphate of copper. 



Article VI. 



New Details respecting Cadmium.* By M. Stromeyer. 



M. Stromeyer has communicated to the Royal Society of 

 Gottingen, at the meeting of Sept. 10, 1818, the first part of 

 his researches on the new metal which he discovered in zinc and 

 its oxides, and to which he has given the name of cadmium. 

 Assisted by two of his pupils, M. Manner, of Brunswick, and 

 M. Siemens, of Hamburgh, he has not only verified his first 

 results, but has been able to give a greater extent to his. 

 researches, and to reduce them to a great degree of precision. 

 He states that he has explained more fully the circumstances 

 which led to the discovery of cadmium ; and in that way has 

 shown the part which M. Hermann, of Schoenbeck, and Dr. 

 RolofF, of Magdeburg, had in it. He gives likewise the names of 

 the different species of zinc, of its oxides, or of its ores, which 

 contain cadmium. Among these last, M. Stromeyer has found 

 it only in a very small proportion in some blendes, with the 

 exception of some varieties of radiated blende of Przibram, in 

 Hungary, which contains two or three per cent, of it. He like- 



* From Annalcn dtr Phjsik, Ix. \93. 



