438 
On the Electromotive Force of Alloys. 
with total resistance of 22, 
ohms, the constant being the 
same, and the liquid as stated above. 
Number. 
Deflection. 
Tan i angle 
of deflection. 
E.M.R 
in volts. 
Po 
185 
193 
195 
198 
197 
196 
194 
198 
189 
104 
202 
•0881 
•0887 
•0896 
•0911 
•0906 
•0902 
•0892 
•0911 
■0874 
•0892 
■0929 
0661 
0-689 
0-696 
0-708 
0-704 
0701 
0-693 
0-708 
0-679 
0-693 
0722 
I 
II 
Ill 
IV 
V 
VI 
VII 
VIII 
IX 
Sn 
1Y. The electromotive force of the alloys of copper and zinc, 
with a total resistance of 2380 ohms, and the same constant 
of galvanometer and the same liquid as in the preceding de- 
termination. 
Number. 
Deflection. 
Tan i angle 
of deflection. 
E.M.F. 
in volts. 
Cu 
43 
34 
40 
43 
47 
55 
115 
203 
234 
•0188 
•0156 
•0184 
•0188 
•0216 
•0253 
•0529 
•0939 
•1763 
0153 
0-130 
0150 
0-153 
0176 
0-206 
0-4.32 
0-708 
0-442 
I 
II 
Ill 
IV 
V 
VI 
VII 
Zn 
It would seem to follow, from the last table at least, that 
in acid solutions the electromotive force of alloys is determined 
by the proportional part of that metal which is most readily 
attacked by the acid. 
The general differences in the behaviour of the two sets of 
alloys may perhaps be accounted for by the distinction which 
Matthiessen* made between the two kinds of alloys. He 
classes an alloy of lead and tin among those which are 
" solidified solutions of one metal in another," while he calls 
alloys like copper and zinc " solidified solutions of one metal 
in an allotropic modification of another." 
* British- Association Report, 1863. p. 47. 
