41 
nitrates. The length of time during which the copj^er was 
exposed to the action of these solutions varied from 18 to 
150 hours. The only liquid which exercised any solvent 
action upon the copper was that containing the large quan- 
tity of 28‘56 grains per gallon of ammonium nitrate ; this 
action was manifested only after 150 hours’ contact of the 
liquid with the copper, the amount of metal which had then 
passed into solution being equal to S milligrams per litre, 
or 0’21 grains per gallon. 
The general conclusion to be drawn from these experi- 
ments therefore undoubtedly is, that at ordinary tempera- 
ture neither distilled water nor water containing the salts 
which commonly occur in drinking waters exercises a solvent 
action upon copper. 
That water charged with carbon dioxide will dissolve 
copper is apparent from the following figures, which repre- 
sent the amounts of that metal found by Dr. Milne in vari- 
ous samples of aerated beverages. 
Table E. 
Copper found in various aerated beverages. 
Description 
of liquid. 
Soda water 
Quantity of copper 
in grains per gallon, 
-084 
Potash water 
*098 
Lemonade 
*053 
Ginger ale 
-053 
Potash water 
TOO 
Aerated water 
-089 
Soda water . 
*100 
Aerated water 
*084 
Soda water 
’036 
In order to arrive at some accurate measurements of this 
solvent action of water containing carbon dioxide upon 
copper, I prepared a number of solutions charged with that 
gas at the ordinary atmospheric 
pressure and placed in each 
a piece of clean copper foil exposing a surface of 2100 sq. mm. 
The amount of copper dissolved 
was estimated by adding 
