DOVE ON THE ELECTRICITY OF INDUCTION. 153 



mena are either the effect of a real magnetism in the metals, or 

 due to associated iron, as unnecessary, as they may be the results 

 of another force. Lame* expresses himself in the same manner 

 with relation to the experiments of Coulomb, Becquerel an d 

 Lebaillif. Lebailliff observed attraction with his sideroscope, 

 when platinum,iron, nickel and cobalt were used; repulsion, on the 

 contrary, with bismuth and antimony. Saigey X maintains, as the 

 result of an extended series of experiments, that repulsion is the 

 common property of all bodies suspended in the air, but that at- 

 traction is always due to the presence of iron. Ampere and De 

 la Rive studied the action of a powerful magnet upon a disc of 

 copper suspended so that it could move freely within a copper 

 wire through which an electrical current circulated. 



This electro-magnetized copper was affected by the poles of a 

 powerful magnet in an analogous manner to electro-magnetized 

 iron, according to a statement with Avhich however I am imper- 

 fectly acquainted. Becquerel §, on the contrary, found no com- 

 plete parallelism between the phasnomena of a copper and iron 

 needle, when both were suspended in the coils of a multiplier. 

 His experiments agree with those of Muncke||, who found that 

 brass containing iron disposed itself in a more or less transverse 

 position between the similar poles of two magnets. Seebeck^ 

 has proved the same property to exist in other substances besides 

 those containing nickel. In these experiments the following 

 metals exhibited transverse magnetic polarization : — 



(1.) Copper wires from one-half to fom- lines in thickness. 



(2.) Platinum in the form of rods, foil, and a^ spongy pla- 

 tinum. 



(3.) A cast rod of speiscobalt containing arsenic and nickel. 



(4.) A strip of gold with 1 per cent, silver, copper and iron, 

 and one purified with antimon3\ 



(5.) Regulus of arsenic containing iron. 



(6.) Alloys** consisting of 3 copper and 1 antimony, and of 1 

 copper and 1 antimony. 



(7.) Alloys of 5 copper and 1 bismuth, 1 copper and 1 bis- 

 muth, and 1 copper and 3 bismuth. 



• Cours de Physique, ii. 149. f Bulletin Universel, viii. p. 87. 



J Ibid. ix. p. 95. § Aiinales de Chimie el de Physique, xxv. p. 2C9. 



y I'opgendoi-ffs Annalen, vi. p. .'5G1. 



if Abhandlungen der Berliner Akademie, 1S27, p. M7. 



*• These alloys are the sanip ms those mentioned at § 53. 



M 2 



