471 



Sulphuric acid was next added, to precipitate any ex- 

 cess of barytes ; and, this being separated by filtration, sul- 

 phuretted hydrogen was passed through the solution, which 

 threw down the antimony as orange tersulphuret. The 

 vessel being placed upon the sand bath for about an hour, 

 so as to expel any excess of sulphuretted hydrogen, the 

 precipitate was collected on a filter, and exposed for a con- 

 siderable time to a temperature not exceeding 212°. Being 

 thus rendered perfectly dry, it was found to weigh 8*85 

 grains, equivalent to 6*37 metallic antimony. 



The solution from which the antimony was separated 

 was supersaturated with ammonia, and sulphuretted hydro- 

 gen was again passed through it, which threw down the 

 iron ; upon this precipitate nitro-muriatic acid was digested, 

 and the unacidified sulphur being separated by a filter, the 

 acid solution was supersaturated with ammonia, which threw 

 down peroxide of iron, weighing, when ignited, 0'244 grains, 

 equivalent to 0*17 grains of iron. The following, therefore, 

 are the results of the analysis : 



Sulphur 7-25 



Lead 30-52 



Iron . 0-17 



Antimony 6*37 



Loss 0-21 



100 parts therefore of the ore consist of 



(1) (2) (3) (4) 



Sulphur. . . 16-36 . 1-016 . 1-016 . 9-153 



r. : : : °Z : "■-} »- • «•« 



Antimony . . 1439 . 0-111 . 0-111 . I'OOO 



100 

 The numbers in column (2) are the quotients obtained by 

 dividing the corresponding ones in column (1) by the atomic 



