460 
ON THE ELECTRO-CHEMICAL EQUIVALENT OF SILVER. 
the determination of electric currents in various experiments, e.g., for the determination 
of the constant of magnetic rotation (Proc., June, 1884), it seemed desirable to supple¬ 
ment Table XI. with observations of later date. Two further absolute determinations 
have accordingly been made on November 21 and November 27, 1884, by the method 
of § 38, with the following results :— 
Table XI. (continued). 
Date. 
Cell used. 
Temperature. 
E.M.F. in B.A. 
volts. 
Correction to 
15°. 
E.M.F. in B.A. 
volts corrected 
to 15°. 
November 21 . 
„ 27 . . 
Clabe No . 1 . 
„ No. 1 . 
13 ° 7 
13-4 
1-4548 
1-4555 
-•0016 
-•0019 
1-4532 
1-4536 
Mean . . 
1-4534 
The difference between P4534 and the mean of Table XI., viz., P4542, would 
indicate a fall of about w oujtj, but the determinations are hardly precise enough to 
warrant ns in regarding this fall as an established fact. 
Note 2 to § 37. 
Two further determinations of the E.M.F. of Clark cells have been published 
since this paper was communicated to the Royal Society. They both depend upon 
the evaluation of currents.by means of silver, as in § 38. 
A. v. Ettingshausen (Zeitschrift fiir Elektrotechnik, 1884, xvi. Heft) finds at 
15°*5 the value l - 433 volt, using Kohlrausch’s (second) value of the electro-chemical 
'equivalent. 
Again (Amer. Journ. Sci., Nov., 1884) Mr. Carhart obtains P434 volt. This 
appears to correspond to a temperature of 18°. 
These results are satisfactory as tending to show that Clark cells may be set up in 
different places and by different hands so as to give nearly identical E.M.F. 
