145 
Table III. 
Salt. 
Grams 
per litre. 
Surface 
of Lead in 
sq. c.m. 
Total Lead 
in solution, 
in Mgms., 
after 18 days. 
Potassium Carbonate,,. 
0-20 
50 
0.3 
,, Nitrate 
0-20 
50 
2-4 
Ammonium ,, 
0’20 
50 
3-8 
In these experiments the lead had not been previously- 
immersed in saline solutions. 
5. The following experiments have especial reference to the 
action of time in determining the quantity of lead dissolved 
by a water containing Potassium Carbonate in solution. 
Table IY. 
Experiments in Beakers, Corked Flasks, and Basins, details of 
MEASUREMENTS, &C., AS IN LAST PaPER (xvi. p. 3). In EACH CASE 
SOOCB.C. OP LIQUID CONTAINING 0-20 GRAMS OF POTASSIUM CaR' 
DONATE PER LITRE. 50 Sq. CM. OP SURFACE OP LEAD EXPOSED. 
8 days. 
Total Lead, in Mgms., 
10 days. 
in solution after 
12 days. 
20 days. 
Flask 
0‘20 . 
0*20 
. 0‘20 
. 0-20 
Beaker 
0-30 . 
0-30 
0.30 
0-30 
Basin 
0-40 . 
0-40 
. 0-40 
, 0-40 
6. The results of these experiments are rather peculiar : 
they certainly shew that the action upon lead of all the 
saline liquids with which I have experimented is an exceed- 
ingly complicated one, and that it is very difficult to separate 
one set of conditioning circumstances from all others. 
In the case of Potassium Carbonate a maximum was reached 
so soon as at the end of eight days : after this time the 
quantity of lead in solution did not increase. If however 
the lead have been previously immersed in a solution of 
either Potassium Nitrate, Calcium Chloride, or Ammonium 
Sulphate, then the solvent action of the Potassium Carbo- 
nate Solution continues to increase (at least throughout so 
long a period as 62 days) although but to a very slight 
