THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOUENAL OF SCIENCE. 



[FIFTH SERIES.] 



NOVEMBER 1879. 



XL. On the Relation between the Thermoelectric Properties, 

 the Specific Resistance, anal the Hardness of Steel. By Carl 

 Bartjs, Ph.D., of Cincinnati*. 



[Plate XI. figs 1-6. j 



I. Introductory Remarks. 



THE experiments which gave rise to the following paper 

 were commenced with the view of further studying the 

 relation between the maximum of permanent magnetism, 

 hardness, and form of steel, a subject proposed for inaugural 

 work by Prof. Kohlrausch. 



Although this question had elicited considerable experimen- 

 tation ever since Coulomb's time f , it was not until compara- 

 tively recently that harmonious results were arrived at, chiefly 

 through the labours of Ruths f, Rowland §, Gaugain || , Fromme% 



* Communicated by the Author, having been read in extract before the 

 Physico-Medical Society of Wurzburg on the 18th of January, 1879. 



t Coulomb, Biot. Phys. iii. p. 108, &c. ; Hansteen, Pogg. Ann. iii. 

 p. 236, 1825 ; Muller, Pogg. Ann. lxxxv. p. 157, 1852 ; Pliicker, Pogg. 

 Ann. xciv. p. 28, 1855; Wiedemann, Pogg. Ann. cvi. p. 169, 1859; 

 Lamont, Handbuch d. Magnet, pp. 223, 249-253. 



% Inaugural Dissertation, p. 34 (Darmstadt, 1874) 



§ Phil. Mag. [4] 1. p. 361,1875. 



J| Compt. Bend, lxxxii. p. 145, 1876. 



H Gbtt. Nachr. Nr. 7, 1876, p. 157 et seqq. 



Phil. May. S. 5. Vol. 8. No. 50. Nov. 1879. 2 A 



