1898-99.] Dr H. Marshall on Polarisation Phenomena. 
535 
III. 2-0977 
0-3096 
14-76 
IV. 3*0809 
0*4593 
14-73 
0.0 
3-05 
0-61 
12 
2.30 
3-1 
•58 
23 
2.45 
3-2 
•58 
24 
3.0 
3-3 
•56 
3.15 
3*3 
•56 
3.30 
3-5 
•55 
3.45 
3*5 
•55 
24 
0.0 
2-9 
0-60 
19 
1.55 
3-0 
•58 
24 
2.25 
3-1 
•58 
2.45 
3-2 
•58 
3.10 
3-3 
•58 
3.30 
3-4 
•57 
24 
It was next sought to get a more accurate idea of the actual 
quantity of nickel involved in causing the difference of potential ; 
this was effected by adding a nickel solution of known strength to 
a nickel-free solution undergoing electrolysis in a basin coated with 
nickel. In some experiments the deposit had been previously 
washed and dried in connection with a quantitative experiment. 
In these cases a solution of 5 grams each of ammonium sulphate 
and ammonia was poured into the basin so as not quite to reach the 
edge of the deposit, and this was electrolysed for half-an-hour 
before beginning the experiment proper. In other cases nickel was 
completely deposited from a solution in the ordinary way, and then 
the nickel solution of known strength added without any further 
treatment. The results obtained were exactly alike in the two 
cases. The nickel solution employed contained 11 m.g. of NTi. per 
c.c., and one drop of it corresponded approximately to 0‘45 m.g. 
It was added drop by drop to the electrolytic solution, thoroughly 
mixed with the latter by blowing gently through the liquid, and 
the effect noted. The results obtained are illustrated below. 
Y. 
YI. 
Nickel added. 
o- 
0'45 m.g. 
0- 9 
1- 35 
1-8 
2- 25 
2-7 
4 
Volume of Solution, 135 c.c. Volume of Solution, 130 c.c. 
Volt. 
Amp. 
Volt. 
Amp. 
4-25 
0*60 
3*75 
0-57 
4-1 
•63 
3-65 
•58 
4-0 
•64 
3-5 
•59 
3-9 
•65 
3*4 
•60 
3-8 
•65 
3-35 
*60 
37 
•65 
3*3 
•60 
3-65 
•66 
3-3 
•60 
3-65 
•66 
3-3 
•60 
4-1 
•64 
3-8 
•53 
Next morning 
•53 
