350 /. W. Mallet on the Atomic Weight of Lithium. 



A. C. Oudemans, Jr., published at Leyden in 1853,* which reviews 

 the determination of the equivalents of twenty-two of the ele- 

 ments, chiefly those of the alkaline and earthy metals. The 

 original memoirs I have for the most part been unable to con- 

 sult ; but the work of M. Oudemans supplies all necessary de- 

 tails of the experiments, and contains also judicious critical 

 remarks upon the trustworthiness of the results. 



In 1817 Arfwedsonf discovered lithium, and in the course of 

 his examination of the new element he obtained the following 

 results from which to calculate its atomic weight. 

 ^ (1.) 5*732 grm. of LiO, S0 3 , prepared by dissolving carbon- 

 ate of lithia in sulphuric acid, gave 11 454 grm. of BaO, S0 3 . 



(2.) *597 grm. of LiO, SO 3 appeared to consist of 406 grm. 

 of SO 3 and -191 grm. of LiO. 



(3.) 4*204 grm. of chlorid of lithium gave 13*224 grm. of 

 chorid of silver. 



Soon after, YauquelinJ analyzed anhydrous sulphate of lithia, 

 and found 430 grm. of LiO, S0 3 to yield '875 grm. of BaO, S0 3 . 



C. Gr. Gmelin§ found a little later that 481 grm. of LiO, S0 3 , 

 precipitated by acetate of baryta, gave *953 grm. of BaO, SO 3 ; 

 and that the acetate of lithia produced in this experiment left on 

 ignition '316 grm. of carbonate. 



Stromeyer|| also analyzed sulphate of lithia, and stated its 

 composition as 



Lithia, - 30-819 

 Sulphuric acid, - - 69181 



100- 



In 1828 Kralovanszky^ published some experiments on the 

 equivalent of lithium, in which experiments, as in those of pre- 

 ceding chemists, the precipitation of a solution of sulphate of 

 lithia by acetate of baryta was the method employed. In one 

 analysis 2* grm. of neutral, strongly ignited LiO, S0 3 , gave 

 3'985 grm. of BaO, SO, ; and a second analysis yielded a result 

 from which a slightly higher atomic weight was deducible. 



Hermann** was the next chemist who occupied himself with 

 the equivalent of Lithium. He prepared carbonate of lithia by 

 precipitating a strong solution of chlorid of lithium with car- 

 bonate of ammonia or of soda, washing and igniting the pre- 

 cipitate. A weighed quantity of this carbonate was then brought 



* Historisch-Kritisch Overzigt van de bepaling der iEquivalent-gewigten van 

 twee en twintig metalen door A. C. Oudemans, Jr.— Leiden 1853. 



f Afh. i Kemi, Fysik och Mineralogie, vi. Schweig. Journ. xxii, 93-100. Ann. 

 de Chim. et de Phys. [2], x, 82. Pogg. Ann. viii, 189. 



% Ann. de Chim. et de Phys. [2], vii, 287. § Gilbert's Ann. lix, 238. 



|| Stromeyer, Untersuchungen i. 435. Schweig. Journ. xxxiii. 373. 



^[ Schweig. Jour, liv, 234. Berz. Jahresb. ix. 93. 



** Pogg. Ann. xv, 480. Berz. Jahresb. x. 96. 



