39 
Table C. 
Lead dissolved by ivater charged with carbon dioxide at 
ordinary pressure. 
Lead Dissolved. 

Mgms. 
Grains 
In mgms. per litre. 
A 
In grains per gallon. 
per litre. 
per gallon 
After 24 
48 
72 
24 
48 
72 hrs. 
Distilled water char- 
ged with Carbon 
Dioxide 
O 
o 
O 
O 
3 
0-21 
0.21 
0-21 
The water poured 
off, more added 
and again poured 
off, and finally 
fresh water con- 
taining Carbon 
Dioxide added ... 
None. 
None. 
Potassium Carbon- 
I 100 
7'0 
ate and 
> and 
and 
> Merest trace. 
Merest trace. 
Ammonium Nitrate 
20 
1-4 
As the results indicated that water charged with carbon 
dioxide at the ordinary atmospheric pressure exercises no 
considerable solvent action upon lead, and moreover that 
this action ceases on the addition of carbonates ; the large 
amounts of lead, found in some of the samples of sodawater 
examined by Dr. Milne are probably due to the increased 
solvent action of water containing large quantities of carbon 
dioxide forced into it under pressure. In order to test the 
truth of this supposition I have made a few determinations 
of the amounts of lead dissolved by distilled water, and by 
the same water containing known quantities of various salts 
when charged with carbon dioxide at a pressure of several 
atmospheres. 
The apparatus consisted of an ordinary gasogene used for 
making so-called “soda water.” From the known capacity 
of the globe and the weight of sodium carbonate and tartaric 
acid employed the pressure exerted in the interior of the 
vessel by the carbon dioxide was calculated as approxi- 
mately equal to 6 atmospheres. 
The surface of lead exposed measured 750 sq. mm. 
