602 
MESSRS. R. T. GLAZEBROOK AND S. SKINNER ON THE 
and then heat the paste sufficiently to dissolve the crystals, afterwards allowing the mixture to cool, and 
thus to form a saturated solution of mercurous sulphate in a saturated solution of zinc sulphate. The 
presence of the free mercury throughout the paste preserves the basicity of the salt, and is of the 
utmost importance. 
Contact is made with the mercury by means of a platinum wire about No. 22 gauge. This is pro¬ 
tected from contact with the other materials of the cell by being sealed into a glass tube. The ends of 
the wire project from the end of the tube; to one end a piece of copper wire is soldered, the other end 
and a portion of the glass tube dip into the mercury. 
When tested it was found that the E.M.F. of all the cells was about 1 per cent, too 
high, though they agreed fairly among themselves. The cells were not saturated with 
the zinc sulphate, and were probably acid as well. 
On May 26, Nos. 65 and 69 were opened, and crystals of zinc sulphate were 
inserted, while two days later 66 and 70 were also opened. Crystals were dropped 
into these latter cells and stirred into the paste. 
The history of the four cells thus treated is given in Table VII. On August 14 
Nos. 65, 69, and 70, with some other cells, were lent to Mr. E. H. Griffiths. The 
history of these cells is continued in Table IX. Nos. 66, 67, and 68 have been tested 
from time to time since, with the result that No. 66 is about right, while Nos. 67 and 
68 are not far apart, but are about 30 too high. 
Table VII. 
o 
ci 
CO 
r— 1 
rH 
r—1 
CD 
Date. 
O 
AD 
AD 
l>» 
00 
CO 
CA 
o 
-P 
-P 
P 
-P 
CM 
CM 
CM 
CM 
CM 
CM 
Ol 
CO 
02 
c n 
P 
02 
P 
02 
P 
3 
t>* 
>> 
t>* 
to 
cu 
bo 
c3 
c3 
P 
Cj 
p 
2 
l-H 
PH 
§ 
Pd 
1 
l-H 
f^ 
§ 
< 
<3 
<1 
< 
Tempera- 
ture , . 
• • 
• • 
• • 
14-5 
• • 
• • 
15 
16-2 
16-3 
17-3 
17-5 
15 
Number 
65 
67 
* 
30 
33 
19 
# t 
17 
12 
- 3 
— 2 
— 2 
0 
66 
67 
. 0 
73 
66 
fl6 
14 
21 
10 
8 
7 
9 
- 4 
67 
67 
. . 
71 
65 
60 
59 
60 
61 
. . 
30 
68 
62 
, , 
69 
61 
56 
61 
58 
60 
# , 
30 
69 
72 
* 
15 
26 
10 
8 
5 
-2 
- 2 
— 2 
0 
, , 
70 
68 
• • 
68 
59 
f24 
18 
19 
5 
3 
o 
4 
" 
It will be noticed that these unsaturated cells were fairly close together from the 
first, and show every sign of continuing to give results which, though wrong, are 
consistent among themselves. 
* Crystals of zinc sulphate were inserted. 
t Crystals of zinc sulphate were inserted and stirred into the paste. 
