Magnetic Characters of Metals^ ^'c. 70 



which means I have been enabled to separate the magnetic 

 from the unmagnetic portions, and thus to arrive at the con- 

 clusion, that pure bismuth is not susceptible of any direct 

 magnetic action by the mere approach of the poles of a 

 powerful magnet, which I consider a test of far greater cer- 

 tainty and exactness than that of a feeble magnetic needle, 

 whatever may be the delicacy of its suspension ; and as a 

 peculiar class of phenomena become displayed by a sudden 

 development of the powers of an electro-magnet, much mis- 

 conception might rise from its employment. 



22. The most usual impurities of bismuth of commerce are 

 sulphur and arsenic, and occasionally a small portion of sil- 

 ver and iron. On subjecting the drossy part (19) to dilute 

 sulphuric acid, a portion was dissolved; after which the 

 liquid was reduced almost to dryness by evaporation. The 

 residue being diluted with water, and a solution of ferrocy- 

 anuret of potassium being added, it assumed a blue colour, 

 which indicated that a portion of iron had been dissolved 

 from the mass. On dissolving another portion of the dross 

 (19) in dilute sulphuric acid, the presence of iron was again 

 indicated by the addition of bruised gall-nut. Hence it was 

 fair to infer, that the whole of the magnetic action displayed 

 by the mass was due to the iron it contained. 



23. I have examined antimony in the same way, and have 

 found some specimens magnetic, and many others in which 

 magnetic action could not be detected. By thus operating 

 on antimony, however, it would be impossible to form a cor- 

 rect idea of the magnetic or unmagnetic state of that metal ; 

 because, as will appear in the sequel, of its masking, to a 

 considerable extent, the magnetism of even considerable pro- 

 portions of iron, when the two metals form a perfect alloy. 

 Hence, in order to test antimony magnetically, it becomes 

 necessary to ascertain, by chemical processes, that it is per- 

 fectly pure, and especially that it is free from iron ; for, al- 

 though antimony will mask the magnetism of iron when in 

 perfect union with that metal, a very trifling proportion of 

 uncombined iron will render the whole mass apparently mag- 

 netic By attending to these particulai's, pure antimony will 

 not be found to display any magnetic action. (17.) 



