146 Analysis of the magnctical Py riles. 



After the distillation the pyrites weighed 54-50 ; conse- 

 quently, the addition ot" sulphur was 9 per cent., making 

 the total = 45*50 or 46 per cent. The powder was become 

 greenish vellow, verv like that of the common pyrites,: it 

 did not auord any sulpliuretted hydrogen when digested in 

 muriaiie acid ; but it nevertheless was partially dissolved, 

 and the solution, when examined by prussiate of potash, 

 and by ammonia, was not different from that of the crude 

 inagnetiea! pyrites. 



The powder which had been distilled with sulphur, and 

 which had thus received an addition of 9 per cent, to its 

 original quanlily, was still capable of being completely 

 taken up by a magnet. 



From the whole of the experiments which have been re- 

 lated, it is therefore evident, that iron, when combined with 

 a considerable proportion of sulphur, is not only still capable 

 of receiving the magnetic property, but is also thereby ena- 

 bled to retain it, and thus, as I have already remarked, be- 

 comes a conipicte magnet ; and it is not a little curious, that 

 iron combined, as above stated, with 45 or 46 per cent, of 

 sulphur, is capable of being taken up by a magnet, whilst 

 iron combined with 52 percent, or more of sulphur, (al- 

 thouirh likewise in the metallic slate,) does not sensibly 

 aflect the magnetic needle ; and hence, small as the differ- 

 ence may appear, there is reason to conclude tliat the capa- 

 city of iron for magnetic action is destroyed by a certain 

 proportion of sulphur, the effects of which, although little 

 if at all sensible at 46 per cent., are yet nearly or quite ab- 

 solute, in this destruction of magnetic influence, before it 

 amounts to 52. But what the exact intermediate propor- 

 tion of sulphur mav be which is adequate to produce this 

 eflect, I have not as yet determined by actual experiment. 



As carbon acts on soft iron, (which, although it most 

 rcadilv receives the magnetic influence, is unable to retain 

 it so as to become a magnet without the addition of a cer- 

 tain proportion of carbon, by which it is rendered hard and 

 brittle, or, in other words, is converted into steel,) so, in 

 like manner, doe:? sulphur seem to act; for it has been 

 proved, bv the preceding experiments, that the brittle mass 

 forn\cd bv the union of a certain proportion of this sub- 

 stance with Iron, whether by nature or by art, becomes ca- 

 pable oF retaining the magnetic virtue, and of acting as a 

 complete magnet. 



'I'liis rcjuarkable coincidence in the efl'ects produced on 

 iron by carbon and sulphur, induced me to try the effects 

 uf phospliorus j and my hope of success was increased bv 



the 



