388 ZINC, CADMIUM, LEAD, &C. 



with a quantity of the matter which adheres to 

 the roof of the room in which zinc is smelted in 

 Bristol. This sublimate contains about ten per 

 cent, of cerium ; by extracting it, I have had 

 it in my power to examine the constitution of 

 its different salts. Stromeyer, to whom we are 

 indebted for our knowledge of this metal, has 

 analyzed several of its salts, and ascertained how 

 much the metal increases in weight when it is 

 converted into an oxide : and from the well 

 known precision of this excellent chemist, we 

 have every reason to expect that the results of 

 his analyses will give us the atomic weight of 

 this metal, at least exceedingly near the truth. 

 It will be proper, therefore, in the first place to 

 state his experiments. 



M. Stromeyer analyzed the carbonate, sul- 

 phate, nitrate, muriate, phospate, and borate of 

 cadmium. He has not yet published the details 

 of his analyses ; or at least, the second volume of 

 his Untersuchungen, in which they will probably 

 be found, has not yet reached Great Britain. 

 This puts it out of our power to judge of the 

 accuracy of the data which he employed in his 

 calculations. Under this uncertainty, I shall 

 make choice of the sulphate to determine the 

 atomic weight of cadmium, because I know 

 from other analyses which he has published in 

 detail, that he employs the constituents of sul- 

 phate of barytes as given by Berzelius, which, 



