138 hitellisence and Miscellaneous Articles. 



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Metallic sulphurets, prepared in the usual way, may be employed 

 in the same way as the oxides, for precipitating oxides from their 

 solutions 'j the latter are then converted into sulphurets, whilst the 

 raetal of the sulphuret continues in the state of oxide with the acid, 

 previously united with the metal precipitated ; this action of the 

 sulphurets frequently possesses advantages in chemical analysis. 



The results obtained by employing eight metallic sulphurets will 

 be stated j they were prepared either by precipitation with sulphu- 

 retted hydrogen or an alkaline hydrosulphate. In operating on the 

 solution of a salt by a sulphuret, the sulphuret was always used in 

 excess, and the mixture was exposed to a boiling heat for about a 

 quarter of an hour. 



Sulphuret o/'Leat;? precipitates nitrate of silver, sesquichloride of 

 iron, nitrate of copper j it does not precipitate nitrate of cobalt, ni- 

 trate of cadmium, nitrate of manganese, sulphate of nickel. 



Sulphuret of Cobalt precipitates acetate of lead, sesquichloride of 

 iron, sulphate of cadmium, sulphate of copper, nitrate of nickel, 

 nitrate of silver; it does not precipitate sulphate of manganese. 



Sulphuret of Iron precipitates nitrate of lead, sulphate of cad- 

 mium, sulphate of copper, nitrate of silver ; it does not precipitate 

 nitrate of cobalt, sulphate of manganese, nitrate of nickel. 



Sulphuret of Cadmium precipitates nitrate of lead, sulphate of 

 copper, nitrate of silver; it does not precipitate nitrate of cobalt, 

 sesquichloride of iron, sulphate of manganese, nitrate of nickel. 



Sulphuret of Manganese precipitates acetate of lead, nitrate of 

 cobalt, sesquichloride of iron, sulphate of cadmium, sulphate of cop- 

 per, nitrate of nickel, nitrate of silver. 



Sulphuret of Copper precipitates nitrate of silver ; it does not pre- 

 cipitate acetate of lead, nitrate of cobalt, sesquichloride of iron, 

 sulphate of cadmium, sulphate of manganese, nitrate of nickel. 



Sulphuret of Nickel precipitates acetate of lead, sesquichloride of 

 iron, sulphate of cadmium, sulphate of copper, sulphate of silver; 

 it does not precipitate nitrate of cobalt, sulphate of manganese. 



Sulphuret of Silver does not precipitate acetate of lead, nitrate of 

 cobalt, sesquichloride of iron, sulphate of cadmium, sulphate of 

 copper, sulphate of manganese, nitrate of nickel. 



It will be observed on examination that sulphuret of manganese 

 decomposes all the solutions of raetaUic oxides tried, while the sul- 

 phuret of silver did not decompose any one whatever j it results 

 from these facts that if silver has the strongest and manganese the 

 weakest affinity for sulphur, all the other metals are intermediate as 

 to these, and arranged according to their degrees of affinity for 

 sulpliur; they stand thus: silver, copper, lead, cadmium, iron, nickel, 

 cobalt, manganese. 



The metals are here so arranged that any one of them in state of 

 sulphuret does not act upon a solution of the metals following: thus 

 for example, the sulphuret of nickel precipitates the salts of silver, 

 copper, lead, cadmium, and iron, but effects no change in those of 

 cobalt and manganese. 



There is only one exception, it is that the sulphuret of iron pre- 



