MR. HATCHETT ON MAGNiiTlCAL PYRITES, 1 



The internal colour and luftre of the produ6l, were not very/e^em^is^ ^(^^^ 



1-1 I /- r 1 -1 ■ i r I r ^^^ pyrites ; 



Mnhke thole o^ the magnetical pyrites; and, after the nials j^^^ ^y^^^, ^.^p^j^j^ 



had been placed during a few hours between magnetical barsj of magnctitra. 

 I found that it pofietred fo ftrong a degree of polarity, as to 

 attraft or repel the needle completely round upon its pivot; 

 and although I'everdl weeks have elapfed fince it has been re- 

 moved from the magnetical bars, it ftill retains its power, with 

 little diminution ; like the magnetical pyrites, however, in 

 its natural fiate, it is not fufficiently powerful to aUra6t and 

 take up iron filings. 



But this fulphuret did not contain fo much fulphur as the It contained lefs 

 magnetical pyrites; I therefore mixed fome of it, reduced tf> „'^a^^,,-eticaP ' ^ 

 powder, with a large quantity of fulphur, and fubjecled it to pyrites. More 



diftillation in a retort, which was at length heated until the ^"'p!""' ^^^.^^ 

 . . ' o and low Ignition. 



mtire bulb became red. 



The fulphuret, by this operation, had allumed very much Itwasattraaablc 

 ., r .!' ^ r •. ■ r r^ by the magnet. 



the appearance or the powaer of common pyrites, in relpect 



to colour; but, in its chemical properties, fuch as folubility in 

 muriatic acid, with the production of fulphurelted hydrogen 

 gas, as well as in the nature of the precipitates it afforded with 

 prufHate of potatli and with ammonia, it perfectly refembled 

 the magnetical pyrites. Moreover, by analyfis, it was found 

 to confiii of 35 parts of fulphur and 65 of iron ; and although 

 (being in a pulverulent ftate) its power,' as to receiving and 

 retaining tlie magnetic property, could not fo eafily be examin- 

 ed, yet, by being powerfully at traded by the magnet, with 

 foine other circumftances, there was every reafon to conclude, 

 that in this refped alfo it was not inferior. 



Another proportion of fulphuret was formed, as above de- 

 fcribed ; it was placed between magnetical bars, and, in like 

 manner, received and retained the magnetic power. 



It is certain, therefore, that when a quantity of fulphur equal Hence 36 or 37 



to 35 or 37 per cent, is combined with iron, it not only does not P^"^ Z^^"'* °*^' 

 J ^ J n-'t prevent iron 



prevent the iron from receiving the magnetic fluid, but enables from becoming a 



it to retain it, fo that the mafs ads in every refped as a per- ™^S"«'* 



manent magnet. 



Black oxide of iron, by one operation, docs not appear to Black oxide 0^ 



combine with fulphur fo readily as iron tilings; a fecond opera- ""p" combines 

 .> . ' -ri ^''^'^ fulphur ;efi 



tjon, however, converts it into a fulphuret, very much re- readily. 



feiubliug that which has juft been defcribedi- ii)cluding the 



[ hani;:.. chemical 



