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LXII. On the Variations in the Electrical Resistance of Anti- 

 mony and Cobalt in a Magnetic Field. By Dr. Gr. Fae, 

 Assistant in the Physical Institute of the Royal University of 

 Padua*. 



IN a series of researches, still in progress, on the variations 

 in the electrical resistance of different bodies when 

 brought into a magnetic field, I arrived at some results with 

 antimony and cobalt which I believe to be new and interesting. 

 Reserving for a future occasion a fuller account of my inves- 

 tigations and also of the methods and instruments employed, 

 I think it may not be useless to publish a preliminary notice. 



It is well known, particularly from the experiments of Sir 

 W. Thomson and M. A. Righi, that magnetism has a distinct 

 influence on the electrical resistance of iron and nickel, and 

 much more upon that of bismuth f- Looking at the coeffi- 

 cients of rotation found by Hall, Righi, and others, and at the 

 explanations given, the idea suggests itself that a connexion 

 may exist between these coefficients and the variation of the 

 electrical resistance in a magnetic field. On the other hand, 

 the difference in the behaviour of iron and bismuth in a mag- 

 netic field seems to be connected with the fact that the first of 

 these two metals is paramagnetic and the second diamagnetic. 

 From these considerations and from others, which I shall not 

 now enter upon, I have undertaken to examine various sub- 

 stances. The results of my experiments agree with my 

 previsions. 



First of all I thought that cobalt and antimony would in par- 

 ticular be worthy of investigation % . Cobalt, as is well known, 

 occupies the third place in the list of paramagnetic metals, 

 whilst antimony is found immediately after bismuth in the 

 list of diamagnetic metals. 



I have examined antimony in the form of very small cylin- 

 ders, which I prepared by melting the metal in a crucible 

 and drawing it into thin glass tubes. The glass was after- 

 wards broken and taken away by alternately cooling and 

 heating. Two thick wires of copper were soldered in the 

 ends of the cylinders in order to connect them up in the elec- 

 trical circuit. As I shall describe on another occasion the 



* Communicated by the Author. 



t From experiments repeated by myself, I have obtained results agree- 

 ing with those of Sir W. Thomson for nickel and with those of M. Righi 

 for bismuth. 



\ And manganese also ; but I have not yet been able to get it pure and 

 in a convenient form. 



