95 



January 14, 1858. 



The LORD WROTTESLEY, President, in the Chair. 

 The following communications were read : 



I. " On the Electric-Conducting Power of the Metals/' By 

 AUGUSTUS MATTHIESSEN, Ph,D. Communicated by C. 

 WHEATSTONE, Esq. Received November 20, 1857. 



(Abstract.) 



The following values for the conducting power of the metals were 

 determined in the Physical Laboratory at Heidelberg, under the di- 

 rection of Professor Kirchhoff, by the same method as is described in 

 the < Philosophical Magazine,' Feb. 1857. 



Conducting Power at Temp, in Celsius's degrees. 



Silver 100 



Copper, No. 3 77'43 18'8 



Copper, No. 2 72-06 22-6 



Gold 55-19 21-8 



Sodium 37-43 21-7 



Aluminium 33'76 19'6 



Copper, No. 1 30-63 24-2 



Zinc 27-39 17'6 



Magnesium 25-47 17'0 



Calcium. 22*14 168 



Cadmium 22-10 18'8 



Potassium 20'85 20-4 



Lithium 19'00 20'0 



Iron 14-44 20'4 



Palladium 12-64 17'2 



Tin 11-45 21-0 



Platinum 10-53 20'7 



Lead 7-77 17'3 



Argentine 7'67 18'7 



Strontium 6-.71 20'0 



Antimony 4-29 18'7 



