242 ^*^ METALLIC SULPHURETS. 



XI. 



Analysis of some metallic Sulphurets. By Mr, Gueniveau, 



Mine Engineer*. 



Proportion of OEVEHAL chemists, pavticularly Messrs. Proust and 

 the metal in Hatchett, have paid attention to metallic sulphurets. The 



sulphurets ' ^_ 



constant. first of these gentlemen has shown, that certain metals, as 



iron, copper, and lead, combine with sulphur in the metal- 

 lic state and in a constant proportion. Mr. Hatchett has 



Magnetic and given an analysis of the magnetic pyrites, which he consi- 

 ders as a sulphuret of iron at a minimum, and 'that of se- 

 veral common pyrites, in which he finds other principles 



Some still ad- beside iron and sulphur. The experiments of these two 



other pyrites. 



mens examin- 

 ed. 



"ei*^ "^ ^f^"^^' scientific gentlemen however have not impressed conviction 

 gea. on the mind of every chemist; and some appear still to ad- 



mit the presence of oxigen in sulphurets of iron. They 

 found their objections chiefly on this, that Mr. Proust em- 

 ployed the method of synthesis, which always leaves some 

 uncertainty in the proportions : and that Mr. Hatchett as- 

 certained the sulphur only by means of sulphate of barytes, 

 respecting the composition of which some uncertainty still 

 Vainotis sped- remains. Having had occasion to analyse certain metallic 

 sulphurets, I determined their elements with a great deal 

 of care, in order to satisfy myself on the points just men- 

 tioned. 

 Sulphuret of The specimen of sulphuret of iron, on which I made all 

 ^'^°'^* the experiments I am about to describe, was amorphous, 



without any mixture of gangue. Its colour was the com- 

 mon bronze yellow of iron pyrites. Various preliminary ex- 

 periments convinced me, that this mineral contained no 

 earthy substance, and no other metal than iron. I shall 

 now proceed to describe the methods I employed to deter- 

 mine with precision the quantities of iron and sulphur they 

 contained. 



* .Tournal des Mines, vol, XXI, p. 105. A translation of a paper 

 bj' Mr. Gueniveau on the Desulphuration of Metals, in the same work, 

 was given in our Journal for November last, vol. XVIII, p. 197.. 



I. Examination 



