MO 



METALLIC SULPHURETS. 



Emulation of 

 pyrites 



quelin lias publifhed on the fulphurets, I thought I ought no' 

 longer to delay making known the fa&s which have induced 

 me to adopt a different opinion. I made ufe of the fine cubi- 

 cal and dodecahedral- pyrites, which are obtained in abun- 

 dance from an indurated argill, found in the vicinity of San 

 Pedro Marino, near the town of Soria. 



Four hundred grains of entire pyrites of the fize of hemp- 

 feed, diitilled by a red heat, yielded, 



Of Pure fulphur - 75 grains 



Refiduum - 322 



Lofs - 3 



Total 400 



Four hundred grains of the fame of a little larger fize, 

 yielded, 



Sulphur - 81 grains 



Refiduum - 314 

 Lofs - 5 



converts them 

 into fulphuret 



400 

 A moderately red heat is fufficient for extracting all the 

 fulphur which they are able to yield. In the firft moments, 

 a fmall quantity of aqueous vapour paffes over ; afterwards, 

 two gales, which may eafily be recognifed by their fmell, 

 namely, the fulphureous and hydrogen-fulphureous, w r hich mu- 

 tually decompofe each other in the w r ater of the receiver, and 

 render it milky. Both are owing to the decompofition of the 

 humidity ; the fulphur patfes over afterwards, and the gas is 

 no longer perceived. 



The abstraction of about 20 parts in 100 of the fulphur from 

 the pyrites, deftroys in a great meafure their metallic luftre* 

 and folidity ; and though they preferve their form, they are 

 more voluminous, melted on all fides, and may be cruflied 

 between the fingers j they have only the dull colour of an ar- 

 tificial" fulphuret. 

 They contain no Hence it is evident, on comparing the produces, that if 

 ©xigen. oxigen conftitutcd part of the pyrites, we muft feek it in the 



refiduum of their diltillation ; but the following facls annihilate 

 the hope of finding it there. 

 Proof. When we treat the different oxides of iron with fulphur or 



cinnabar, in a red heat, the refults are, fulphureous gas, and 

 common fulphuret of iron. If therefore the pyrites contained 

 • * ■ " ©xigen, 



