with water. With an electric pressure of 3.5 to 4
volts, this will give an even deposit of copper on the article
being plated.
A solution for silver plating may be prepared as follows: Dissolve
3/4 oz. of commercial silver nitrate in 8 oz. of water, and slowly
add a strong solution of potassium cyanide until no more white
precipitate is thrown down. Then pour the liquid off and wash the
precipitate carefully. This is best done by filling the bottle
with water, shaking, allowing precipitate to settle and then
pouring off the water. Repeat six times. Having finished washing
the precipitate, slowly add to it a solution of potassium cyanide
until all the precipitate is dissolved. Then add an excess of
potassium cyanide--about as much as was used in dissolving the
precipitate--and make the solution up to 1 qt. with water. This
solution, with an electric pressure of 2 to 4 volts, will give a
good white coat of silver in twenty minutes to half-an-hour; use 2
volts for large articles, and 4 volts for very small ones. If more
solution is required, it is only necessary to double all given
quantities.
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