40 
Table D. 
Lead dissolved hy water charged with carbon dioxide at a 
pressure of about 6 atmospheres. 
Salt. 
Mgms. 
per 
litre. 
Grains 
per 
gallon. 
Lead Dissolved. 
In Mgms, 
24 hours. 
. per litre. 
48 hours. 
In Grains 
24 hours. 
per gallon. 
48 hours. 
Potassium Carbonate.. 
Ditto 
Calcium Chloride 
Ammonium Nitrate . . . 
Ditto 
Distilled Water 
80 
160 
160 
16 
40 
5-60 
11-20 
11-20 
1-12 
2-80 
13- 2 
32 
5 
10 
14- 8 
32-0 
6-0 
44 
35 
24 
0-924 
2-24 
0-35 
0- 70 
1- 036 
2- 24 
0- 42 
3- 08 
2-45 
1- 68 
It appears from these numbers that distilled water charged 
with carbon dioxide under a pressure of (approximately) 6 
atmospheres dissolves five times as much lead as the same 
water charged with the gas at the ordinary atmospheric 
pressure : that the presence of a small quantity of ammo^ 
Ilium nitrate does not increase the solvent action until after 
a lapse of 48 hours or so : and that potassium carbonate, 
when present in somewhat large quantities, exerts a marked 
deterrent action. The amount of lead dissolved, however, 
even in the presence of potassium carbonate, is far too large 
to allow of such a water being drunk with safety. 
II. Action on Copper. 
The experiments under this heading were carried out in a 
manner similar to that already described. The pieces of 
copper foil presented a surface of 420 sq. mm. to the action 
of the various solutions. The results obtained were with 
one exception negative : no copper was dissolved. The 
action of the following liquids was examined: — 
wcder; the same containing ammonium Qiitrate in quaiiti- 
ties varying from '02 grams per litre ( = 1*4 grains per gallon) 
to *408 grams per litre ( = 28*56 grains per gallon); the 
same containing potassium nitrate in like amounts; the 
same containing ammonium sulphate in quantities varying 
from *10 to *20 grams per litre ( = 7 to 14 grains per gallon) : 
and also distilled water containing simultaneously carbonates 
and, nitrates, carbonates and sidphates, and chlorides and 
