504 M. Regnault on the Specific Heat of Simple Bodies, 



chemical composition, the product of the specific heat by the atomic 

 weight is the lower the less the atomic weight is. 



Besides, for the chlorides of the formula R CI*, this product is — 

 For chloride of calcium . . . 114'72 

 For chloride of barium . . . 116-44 



I think it may be thence concluded, that the formula of 

 chloride of lithium is R*C1*; and that lithium ought to be 

 ranged among the alkaline metals, and not among the alkaline 

 earths. Nevertheless, as the product of the specific heat by the 

 atomic weight is decidedly less for chloride of lithium than for 

 the chlorides of potassium and sodium, it would be advantageous 

 to confirm this conclusion by a determination of the specific heat 

 of the isolated metal ; this I shall not fail to do if I succeed iu 

 procuring a sufficient quantity of it. 



Tellurium. 



I made formerly some determinations of the specific heat of 

 tellurium, by uniting the various specimens which were to be 

 found in the collections, and in the possession of the dealers in 

 chemical products in Paris. I found thus the number 0*05155, 

 which, multiplied by 806*5, the equivalent of the body, gives the 

 number 41*57. This product is a little more than that generally 

 found for simple bodies, the purity of which is not open to 

 suspicion. 



The Austrian display presented beautiful specimens of tellu- 

 rium, which had been prepared at the Mint of Vienna by M. 

 Alexander Lowe. I did not allow the opportunity to escape of 

 making new experiments on a product which I had reason to be- 

 lieve was purer than that with which my previous experiments had 

 been made. A notice published by M. Lowe indicates the mode 

 of preparation which he had followed. Here is a brief abstracc 

 of it :— 



The mineral is the auriplumbiferous tellurium of Offenbanya 

 in Transylvania, which contains on an average in 100 parts, — 

 3 parts oi gold, 5 of tellurium, 30 of lead in the state of sul- 

 phuret, and a quartzose gangue. This mineral, reduced to the 

 state of coarse powder, was treated with weak hydrochloric acid 

 to dissolve the carbonates, then attacked in a leaden vessel by 

 concentrated sulphuric acid, which converted the galena into in- 

 soluble sulphate of lead, and dissolved the tellurium as sulphate 

 of oxide of tellurium. The liquid, clarified by having been allowed 

 to stand, was transferred into another leaden vessel containing 

 water, to which hydrochloric acid had been added to prevent the 

 separation of oxide of tellurium. 



The tellurium may be separated from this solution by means 

 of metallic zinc ; but it is then very impure, because it is depo- 



