[ 167 ] 
IV. On the Influence of Temperature on the Electric Conducting-Power of Alloys. By 
Augustus Matthiessen, F.B.S., Lecturer on Chemistry in St. Marys Hospital , and 
Carl Vogt, Ph.D. 
Beceived June 11, — Bead June 18, 1863. 
The influence of temperature on the electric conducting-power of the pure metals in a 
solid state has been proved to be very great*, and as very little is as yet known with 
regard to the influence of temperature on the electric conducting-power of alloys, we 
undertook this research in order, if possible, to discover the law which regulates this 
property. 
For the sake of clearness, we have thought it advisable to divide this subject into four 
parts, and they will be treated of in the following order : — 
1. Experiments on the influence of temperature on the electric conducting-power of 
alloys composed of two metals. 
2. Experiments on the influence of temperature on the electric conducting-power of 
some alloys composed of three metals. 
3. On a method by which the conducting-power of a pure metal may be deduced 
from that of the impure one. 
4. Miscellaneous and general remarks. 
I. Experiments on the Influence of Temperature on the Electric Conducting-power of Alloys 
composed of two Metals. 
It will be as well to mention that, from the few experiments already published on the 
influence of temperature on the conducting-power of alloys, we had at the commence- 
ment of the research some idea of the law which regulates this property, and having 
found after a few experiments our supposition confirmed, we were able to shape the 
course we intended to pursue, in such a manner as to curtail the number of alloys to 
be experimented with. Thus, with the alloys made of the metals lead, tin, cadmium, 
and zinc with one another, instead of using the alloys 
Pb 6 Sn, Pb 4 Sn, Pb 2 Sn, Pb Sn, Pb Sn 2 , Pb Sn 4 , Pb Sn 6 , 
and testing in the same manner the tin- cadmium, tin-zinc, cadmium-zinc alloys, we only 
used the following, 
Sn 6 Pb, Sn 4 Cd, Sn 2 Zn, Pb Sn, ZnCd 2 , SnCd 4 , CdPb 6 , 
thus forming a mixed but complete series. Other groups of alloys have been treated in 
* Philosophical Transactions, 1862, p. 1. 
MDCCCLXIV. 2 A 
