332 



Dr. E. van Aubel's Researches on 



1 1856. 



2 1869. 



3 1868. 



4 1872. 



5 1879. 



6 1880. 



7 1883. 



8 1884. 



9 1888. 

 1889. 



v, ratio of the units. 

 Weber and Kohl- 



rausch 3107 XlO 10 



W. Thomson and 



King 2-808X10 10 



Maxwell 2-842xl0 10 



M'Kichan 2-896 XlO 10 



Ayrton and Perry 2-960xl0 10 



Shida 2-955X10 10 



J. J. Thomson . . . 2-963 X 10 10 



Klemencic 3019 XlO 10 



Himstedt 3-009 XlO 10 



W.Thomson ... 3-004 x 10 10 



Velocity of light. 



1879. Michelson 2 9991 XlO 10 



1882. Michelson 29985xl0 10 



iqqo xr ^ J 2-9986 XlO 10 



1882. Newcomb j 2-9981 xlO 10 



1874. Cornu ~ 2-9850 xlO 10 



1878. Cornu 3-0040 xlO 10 



1880-81. Young & Forbes 3-0138 xlO 10 



1 Weber and Kohlrausch, Electrodyn. Maasbestim., Abh. der Konigl. Sacks. 

 Geselhchaft der Wissensch. v. p. 219 (1856); and Pogg. Ann. 1856. 

 ' 2 King, Beport of the Committee on Electrical Standards, 1869. 



3 Maxwell, Phil. Trans. 1868, p. 643. 



4 Dugald M'Kichan, Phil. Trans. 1879. 



5 Ayrton and Perry, Journ. Soc. Tel. Engineers, 1879, p. 126. 



6 Shida, Phil. Mag. [5] x. p. 431. 



7 J. J. Thomson, Phil. Trans. 1883, p. 707. 



8 Klemencic, Wiener Berichfe [3] lxxxiii. p. 88. 



9 Himstedt, Wied. Ann. no. 9 (1888). 



Johns Hopkins University, Baltimore, 

 June 15, 1889." 



XL. Researches on the Electrical Resistance of Bismuth. 

 By Edmond van Aubel, Doctor of Science*. 



A GREAT many memoirs having been published relating 

 to the influence of temperature upon the electrical 

 resistance of bismuth, I think it advisable to sum up in a few 

 lines the actual state of the question, in order to show the 

 bearing of my researches on the solution of the problem. 



In the present memoir I have examined the electrical 

 conductivity- of bismuth between 0° and 100° only ; I will 

 therefore confine myself to stating the results arrived at by 

 physicists between the same limits of temperature. 



Matthiessenf, in conjunction with von Bose and other 

 physicists, has found the conductivity of bismuth at 0°to be 

 1*245, that of silver being taken as 100, and has expressed 

 the conductivity at f as a function of the conductivity at 0° 

 by the formula 



\,=\ (l-0-0035216£4- 0-000005728^). 



G. Wiedemann, Matthiessen, Holzmann, and Vogt have 



* Communicated by the Physical Society : read June 22, 1889. 



t The works of the physicists, whose names will he mentioned later on, 

 are enumerated in the Treatise on Electricity by Prof. G. Wiedemann, 

 vol. i. 1882, p. 503 and the following pages. 



