RHODIUM. 101 



the amount of silica in the KCl and allowed for it. Weigh- 

 ings for vacuum. {Stas, Untersuch. ilber Chem. Prop.^ 

 Leipzig, 1867.) 



Stas mentions that Dumas, who was the first to place K 

 at 39, afterwards became convinced that this number was 

 too low. {Ibid, page 318.) 



RHODIUM. 



Regnault has determined the specific heat of rhodium. 

 It corresponds to an atomic weight of about 104. ( Gmelin- 

 KraiU, I. c.) 



J. J. Berzelius : 104,.3 (O =16 ). 



Berzelius made two analyses of dipotassic chlororhodiate. 

 This salt can be completely desiccated in a current of chlo- 

 rine at a red heat without decomposition. 3.146 grammes 

 gave on reduction in a current of hydrogen 0.930 CI, and 

 the residue contained 1.304 KCl and 0.912 metallic rhodium. 

 [If KCl = 74.594, CI = 35.457, (Stas,) the atomic weight of 

 the salt calculated from the CI contents is 359.831, and that of 

 Rh 104.272. The relation between the Rh and the CI gives 

 Rh =104.31 2. The relation between the KCl and the Rh 

 gives Rh = 104.340. The mean is 104.308.] Berzelius 

 made a second analysis of the crystallized salt in which he 

 determined the water of crystallization. [Under the same 

 suppositions and in the same order, the resulting values for 

 Rh are 106.279; 104.762; 103.708.] In the Lehrbuch only 

 the former analysis is used to deduce the atomic weight. 

 Rhodium was separated from other metals by its insolu- 

 bility in aqua regia. The double salt was formed by heat- 

 ing finely pulverized Rh in mixture with KCl in a current 

 of chlorine. The double salt was dissolved in water, pre- 

 cipitated with alcohol, washed with alcohol and dried. 

 (Poggend Ann., 13, 1828, 437; Kongl. Vetens. Akad. HandL, 

 1828.) 



In his earlier determination (Rh = 750.68 for = 100) 

 Berzelius mistook an hydrated oxide for a chloride. [Ibid.) 



