40 
Table D. 
Lead dissolved by water charged with carbon dioxide at a 
\ 'pressure of about 6 atmospheres. 
Salt. 
Mgms. 
per 
litre. 
Grains 
per 
gallon. 
Lead Dissolved. 
K 
f 
In Mgms 
21 horn’s. 
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) G 
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- 
nium 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: — distilled 
water ; the same containing ammonium nitrate in quanti- 
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 TO to *20 grams per litre ( = 7 to 14 grains per gallon) : 
and also distilled water containing simultaneously carbonates 
and nitrates, carbonates and sulphates , and chlorides and 
