MR. HATCHETT ON MAGNETICAL PYRTTKS. 11 



6. That iron, when combined naturally or artificially with pm«ts of the 



,. - , , . , -,11 II r • - .« fulphur in mae- 



35.30 or 37 of fulphur, is not only (till capable of receiving the„etic pyrites. 



magnetic fluid, but is alfo rendered capable of retaining it. To as 



to become in every refped a permaneni magnet; and the fame 



may, in a great meafure, be inferred refpeding iron which has 



been artificially combined wiUi 45.30;)er cent, of fulphur. 



7. That beyond this proportion of 45.50 or 4^6 per cent, of Proportion be-' 

 fulphur, (in the natural common pyrites,) all fufceplibilify of^a"c»netic"inflii- 

 the magnetic influence appears to be deflroyed; and, although ence is loft. 

 the precife proportion which is capable of producing this ef- 



fect, has not yet been determined by afiual experiment, it is 

 certain that the limits are between 45.50 and 52.15 ; unlefs fome 

 unknown alteration has taken place in the ftate of the fulphur, 

 or of the iron in the common martial pyrites. 



8. That, as carbon, when combined in a certain proportion As carbon ren- 



with iron, (forming fieel.) enables it to become a permanent .^'^ "^f" tena- 



' \ c> " t cioos or magnet- 



magnet, and as a certain proportion of fulphur communicates ifm, fo alfo d» 



the fame quality to iron, fo alfo were found to be the efTecls of ^'fipj'"^"^"^ v 



^ , .... pholphorus. 



phofphorus; for the phofphuret of iron, in this refpe<^, was by 



much the moft powerful, at leaft when confidered compara- 

 tively with fulphuret of iron. 



9. And laflly, that as carbon, fulphur, and phofphorus, pro- Conclufion* 

 duce, by their union with ironj many chemical effedls of much 

 fimilaritv, fo do each of them, when combined with that metal 



in certain proportions, not only permit it to receive, but alfo 

 give it the peculiar power of retaining, the magnetical proper- 

 ties; and thus, henceforth, in addition to that carburet of iron 

 called fleel, certain fulph^rets and phofphurets of iron maybe 

 regarded as bodies peculiarly fufceptible of iirong magnetical 

 impregnation. 



Having thus, for the greater perfpicuity, reduced the princi- 

 pal fa6ts of this Paper into a concife order, I fliali now make 

 foiiie general obfervalions. 



It is undoubtedly not a little fingular, that a fubrtance like Remarks. 



the magnetical pyrites, wiiich, although not common, has been '^^? "iag"et"j^l 

 » 1 • i-n/iit I't f 1 pyrites IS an in- 



Jong known to mineralogiits, Inould not hitherto have been tcreftingprodua 



chemically examined, efpecially as mineralogical authors have 



mentioned the analylis of it as a defideratum. The refult of 



this which I have attempted, proves that.it is really dcferving 



of notice; for thus we have afcertained, that the fulphuret of 



iion hithprto known only as an artificial produfl, is alfo formed 



