Intelligence and Miscellaneous Articles. 561 



possessed by the sparingly soluble double salts of other platinum 

 metals, among others by the sodiochloride of rhodium. The cry- 

 stallized sesquichloride of ruthenium and potassium is almost inso- 

 luble in a concentrated solution of chloride of ammonium, and I 

 have used this salt in washing the salt of ruthenium, to free it from 

 any admixture of chloride of potassium. This method is far more 

 certain than the employment of spirit, which only removes with dif- 

 ficulty the last traces of that admixture. It is scarcely necessary to 

 observe that the chloride of ammonium must be subsequently ex- 

 tracted with spirit, which however, from the great solubility of the 

 salt, is very readily and quickly effected. 



II. Sesquichloride of Ruthenium and Ammonium, 2NH 4 CI -f- 

 Ru 2 CI 3 , is very easily obtained by mixing the concentrated solution 

 of the black sesquioxide in muriatic acid with chloride of ammonium, 

 and concentrating by evaporation with the addition of a little nitric 

 acid. The salt cannot be distinguished in form and properties from 

 the potash salt ; it leaves, as required by the formula, 32*7 per cent, 

 metal when ignited in a current of hydrogen. Both these salts, 

 although more soluble than KC1 + IrCl 2 , do not dissolve easily in 

 the crystallized state in water ; notwithstanding they crystallize with 

 difficulty from their solutions, and only when these are highly con- 

 centrated. 



III. Sesquichloride of Ruthenium and Sodium ? — This compound 

 could not be obtained crystallized and in a state fit for analysis. It 

 formed a semi-crystalline deliquescent mass, readily soluble in spirit, 

 which dried when strongly heated, but then became partly green 

 and blue, and behaved therefore like a mixture of chloride of sodium 

 and sesquichloride of ruthenium. A. solution of chloride of barium 

 and Ru' 2 CI 3 dried to a deliquescent mass, which resembled the pre- 

 ceding salt, but from which spirit extracted the sesquichloride of 

 ruthenium, leaving behind chloride of barium. 



IV. Perchloride of Ruthenium and Potassium, KC1 + RuCl 2 . — 

 The conversion of Ru 2 CI 3 into RuCl 2 is very difficult. When treated 

 for a long time with nitromuriatic acid, only a very small por- 

 tion passes over into perchloride, and it is impossible to effect its 

 complete conversion. When heated with muriatic acid and chlorate 

 of potash, some of the salt is formed ; but the greater portion of the 

 ruthenium is lost, it being converted into a higher chloride (probably 

 RuCl 3 ), which is volatile and escapes with the aqueous vapours. 

 I unfortunately did not make this observation before I had already 

 consumed most of the ruthenium, and did not possess sufficient to 

 examine more closely this interesting compound. 



I once obtained the perchloride accidentally, having added by 

 mistake too much nitric acid in precipitating the oxide from the 

 rutheniate of potash. The solution of the oxide in nitric acid fil- 

 tered from the precipitated oxide was brown, and yielded, on evapo- 

 ration with some muriatic acid, at first a considerable quantity of 

 crystallized saltpetre ; and on further concentration of the rose- 

 coloured mother-ley a red salt crystallized, which, washed first with 

 chloride of ammonium, then with spirit, was the compound in its 



