On the Electrical Resistivity of ElectTolytic Nickel. 

 Fig. 3.— Electrolytic Nickel Wire (Curve to obtain p at 0° C.) 



57 



6,500 



8,000 



ZSOO 













/ 1 

























ir r . * , 















^paCo^C 



6,955 C.G.^ 











7,000 V 



t,oOQ\ 



10 20 60 40 



TemperdCure Centigrade. 



50 



to 



Xot^ added December 6, 1899. — Since writing the above short paper, 

 I have discovered in a paper by Messrs. A. Matthiessen and C. Vogt * 

 a reference to the sample of nickel with which the present accepted 

 figure for its resistivity was evidently obtained. 



This paper is entitled "On the influence of Temperature on the 

 Electric Conducting Power of Iron and Thallium," and its title would 

 not lead a reader to look in it for a reference to the resistivity of 

 nickel. 



Messrs. Matthiessen and Vogt therein state that samples of sup- 

 posed chemically pure nickel and cobalt wires prepared by M. Deville 

 were given to them by M. Wohler. They measured the resistivity 

 of these samples, but they state that their electrical behaviour gave 

 them reason to believe that this nickel and cobalt were not pure. 

 They give the electrical conductivity of the nickel as 13-11 at 0' C. 

 taking hard drawn silver at 0° C. as 100. 



Hence if hard cbawn silver has a volume resistivity of 1620 C.G.S. 

 units at 0° C, it follows that Matthiessen and Vogt's value for the 

 resistivity of their sample of nickel would be 12,357 C.G.S. units at 



* " PliiL Trans. Eoy. See./ 1863, p. 384. 



