On the Thermoelectrical Properties of Bismuth. 285 



greater certainty if the sand is previously agitated with finely 

 powdered plumbago, or with some sufficiently adherent 

 metallic powder, such as the finer qualities of Bessemer 

 bronze. 



XXXVII. The Effect of Magnetization on the Thermoelectrical 

 and other Physical Properties of Bismuth. By Herbert 

 TOMLINSOff, B.A.* 



IN a paper read before the Koyal Society on January 26, 

 1882f, the author has given an account of an experiment 

 relating to the effect of longitudinal magnetization on the 

 electrical resistance of bismuth. The subject has since been 

 taken up much more fully by Eighi $, Leduc§, Hurion ||, and 

 Albert v. Ettingshausen and Walther NernstH. In the 

 author's paper quoted above are also described experiments 

 on the effects of magnetization on the electrical resistance of 

 iron, steel, nickel, and cobalt, the results of which are sum- 

 marized in the following table : — 



Table I. 







Increase of resistance 











per unit produced 











by a C.G.S. unit of 



Magnetic 



rM.fl 



Metal. 



Condition. 



magnetizing force, 

 Ar 



susceptibility. 



K** 







rMf' 







Iron 



Annealed. 



2335 Xl0~ 8 . 



30 



0-8 xlO- 6 



Steel 



Annealed. 



1500 „ 







Steel 



Unannealed. 



1137 „ 







Steel 



Very hard. 



70 „ 







Nickel ...... 



Annealed. 



8070 „ 



8-8 



9-2 „ 



Nickel 



Unannealed. 



4343 „ 







Cobalt. ... 



Unannealed. 



638 „ 



4-4 



1-4 „ 



Bismuth ... 



Unannealed. 



21 „ 



-•000014ft 



1500 „ 



Copper . . . 



Annealed. 



oil „ 







* Communicated by the Physical Society : read January 28, 1888. 

 + " The Influence of Stress and Strain on the Physical Properties of 

 Matter," Phil. Trans, vol. clxxiv. (1883, part 1). Abstract, Proc. Roy. 

 Soc. No. 218(1882). 



\ Ace. R. dei Lincei, 1883, 1884. 

 § Bull, de la Soc.francaise de Phys. 1884. 

 || Comptes Rendus, 1884, 1885. 

 ^| Sitzb. der kais. Akad. der Wissensch. 1887. 

 ** The values of k were determined for the same magnetizing forces as 

 those used for producing alteration of resistance. 



ft Taken from Von Ettingshausen's determinations ( Wien. Ber. 1882). 

 XX No change amounting to AOo ^ Qoo could be detected with a magne- 

 tizing force of 90 C.G.S. units. 



