the Electromotive Force of Alloys. 437 
I. The electromotive force of the alloys of tin and lead, and 
of the metals themselves, when the resistance is 7180 ohms, 
and the constant of the galvanometer '000003435. 
The first column gives the deflection in millimetres ; the 
second the tangent of one half the angle of deflection ; the 
third the product of the constant by the total resistance ; and 
the fourth the electromotive force in volts. The liquid in 
this case is water. 
Number. 
Deflection. 
Tan ^ angle 
of deflection. 
E.M.F. 
in volts. 
Pb 
207 
205 
182 
173 
212 
184 
216 
175 
208 
195 
164 
•0953 
•0942 
•0837 
•0795 
•0975 
■0846 
■0993 
•0805 
•0956 
•0896 
•0754 
0-238 
0-249 
0-222 
0-201 
0-258 
0224 
0-263 
0-213 
0-253 
0-237 
0-199 
I 
II 
Ill 
IV 
v 
VI 
VII 
VIII 
IX 
Sn 
II. The electromotive force of the alloys of copper and zinc, 
with a total resistance of 19,708 ohms, the constant being the 
same as before, and the liquid fresh pond- water. 
Number. 
Deflection. 
Tan -J angle 
of deflection. 
E.M.F. 
in volts. 
Ou 
10 
12 
17 
52 
64 
106 
131 
218 
228 
•0046 
•0055 
•0078 
•0239 
•0294 
•0487 
•0602 
•1002 
•1048 
0031 
0037 
0053 
0-162 
0-199 
0-330 
0-408 
0-678 
0-709 
I 
II 
Ill 
IV 
v 
VI 
VII 
Zn 
The resistance of distilled water is so great, that it was 
impossible to get any good or satisfactory results. The 
addition of about one tenth of a cubic centimetre of strong 
sulphuric acid to about one hundred and fifty cubic centi- 
metres of distilled water gave the liquid used in the last two 
observations. 
III. The electromotive force of the alloys of lead and tin, 
