Analysis of the magnetical Pyrites. \A.:> 



Since it has been removed from the magnetical bars, it still 

 retains its power with little diminution ; like the magnetical 

 pyrites> however, in its natural state, it is not sufficiently 

 powerful to attract and take up iron filing?. 



But this sulphuret did not contain so much sulphur as 

 the magnetical pyrites; I therefore mixed some of it, reduced 

 to powder, with a large quantity of sulphur, and subjected 

 it to distillation in a retort, which was at length heated Until 

 the intire bulb became red. 



The sulphuret by this operation had assumed very much 

 the appearance of the powder of common pyrites in respect 

 to colour; but in its chemical properties, such as solubility 

 in muriatic acid, with the production of sulphuretted hy- 

 drogen gas, as well as in the nature of the precipitates'it 

 afforded with prussiate of potash and with ammonia, it 

 perfectly resembled the magnetical pyrites. Moreover, by 

 analysis, it was found to consist of 35 parts of sulphur and 

 6b of iron; and although (being in a pulverulent state) its 

 power, as to receiving and retaining the magnetic property, 

 could not so easily be examined, yet, by being powerfully 

 attracted by the magnet, with some other circumstances, 

 there was every reason to conclude that in this respect also 

 it was not inferior. 



Another portion of sulphuret was formed as above de- 

 scribed ; 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 sulphur 

 equal to 35 or 37 per cent, is combined with iron, it not 

 only does not prevent the iron from receiving the magnetic 

 fluid, but enables it to retain it, so that the mass acts in 

 every respect as a permanent magnet. 



Black oxide of iron, by one operation, does not appear 

 to combine with sulphur so readily as iron filings ; a second 

 operation, however, converts it into a sulphuret, very muchi, 

 r(-s(.inbling that which has just been described, includinp- 

 the chemical as well as the magnetical properties; but un- 

 doubtedly by these processes it is progressively converted, 

 perfectly or very nearly, into the metallic state. 



Iron combined with a larger proportion of oxygen, such 

 as the fine gray specular iron from Sweden, will not form 

 a sulphuret by the direct application (»f sulphur in one ope- 

 ration ; although it becomes of a dark brown colour, partly 

 iride-ccnt, and is moderately attracted by a n)a<i;nct. 



50 graiws of the magnetical pyrites, reduced to powder, 

 and mixed with thrt-e times the weight of sulphur, were 

 distillrd in a retort until ihu bulbbrcanii, modtralclv red-hot. 



\'ol. '21 . No. b-i', A/ffrc/MSOi. K. After 



