&1AGNETICAL PYRITES, %Qj 



An Analyfis of the Magnetical Pyrites; ivith Remarks on fame of 

 the other Sulphurets of Iron. By Charles Hatchett, 

 Efq. F. R. S. From the Philofophical Tranfactions for 1 804-. 



§ I. 



vJ'F the various metallic fulphurets which conftitute one ofUniverfal dif- 

 the grand divifions of ores, none appear to be fo univerfally dif- p"^"^" of' n fu!- 

 perfed throughout the globe, as the fulphuret of iron, commonly phurets of iron, 

 called iMartial Pyrites; for the fpecies and varieties of this are 

 found at all depths, and in all climates and foils, whether 

 ancient, or of alluvial and recent formation. It is remarkable 

 alfo, that, under certain circumftances, this fulphuret is daily 

 produced in the humid way ; an inftance of which, a few years 

 back, I had the honour, in conjunction with Mr. Wifeman, to 

 lay before this Society ; * and although, in regard to pecuniary 

 value, the pyrites of iron may be confidered as comparatively 

 infigniiicant, yet there is every reafon to believe, that in the 

 operations of nature, it is a fubftance of very confiderable 

 importance. 



§11. 



The fpecies and varieties of martial pyrites, are in general fo Among the 



11 i ii i r r " i i ii numerous fpecie* 



well known, and have been fo frequently and accurately de- one is remarkable 



fcribed, as to figure, luftre, colour, and other external charac-*" or /* ron g pe- 

 ters, that it would be totally fuperfluous here to give any de- e poai y * 

 tailed account of them. One of the fpecies, however, merits 

 peculiar notice, as poffeffing the remarkable property of ftrong 

 magnetic polarity ; and, although it has been defcribed by mo- 

 dern mineralogifts,f it does not appear to have been as yet fub- 

 jecled to any regular chemical examination; fo that, whether 

 it be a fulphuret of iron inherently endowed with the magneti- 

 cal property, or a fulphuret in which particles of the ordinary 

 magnetical iron ore are fimply but minutely interfperfed, has 

 to this time remained undecided, 



* Phil. Tranf. for 1798, p. 567. 



•j- Kirwan, Vol. II. p. 79. Widenmann, p. 792. Emmerling, 

 Sd edit. Tom. II. p. 286. Karften, p. 48. Brochant, Tome II. 

 p. 232. 



This 



