THE ELECTROLYTIC METHOD OF CLEANING SILVER. 5 
EXPERIMENTAL STUDY OF THE METHOD. 
It was the chief purpose of these experiments to obtain information 
as to the best metal and electrolyte to use, the most economical con- 
centration of the solution, and the most satisfactory temperature for 
cleaning silver as it would ordinarily be accomplished in the home, 
and to study the relative efficiency of the electrolytic and other 
methods. 
Throughout the investigation the methods and apparatus were 
simple and in most cases applicable to household use, more accurate 
procedure being deemed impracticable. In some cases silver which 
had been naturally tarnished by use was cleaned satisfactorily by 
this method, but in order to secure uniform conditions the silver 
used in most tests was tarnished by immersing it in a strong 
potassium-sulphid solution, and in order that the tarnish should be 
uniform for a comparative series of tests, all of the spoons to be 
used in each series were placed in the sulphid solution for the same 
length of time. Porcelain or agate ware dishes were used for hold- 
ing the solution of electrolyte, which was made up by adding dif- 
ferent amounts of soda and salt, etc., to one or two quarts of water. 
The active metal used, aluminum, or zinc, or an alloy of both, and 
the tarnished silver were then placed in direct contact in the solution 
which had previously been heated to the desired temperature, and 
the time necessary for cleaning was noted by a stop watch. 
Since the preliminary tests indicated that either washing or baking 
soda may be used as the electrolyte of the cleaning solution, it 
seemed desirable to ascertain first of all whether either of these salts 
was the more efficient and economical for ordinary household use. 
Experiments were accordingly made to determine the relative effici- 
ency of solutions of washing soda and baking soda without the addi- 
tion of sodium chlorid. The concentration of the solutions was 1 
teaspoonful of the commercial soda to 1 quart of water. The tem- 
perature at which the cleaning was done was approximately 100° C. 
in each case. In each series six spoons were used which had been 
tarnished as described above. The following procedure was 
adopted: The first spoon was cleaned in the washing-soda solution. 
The active metal was then rinsed in clean water, transferred to the 
baking-soda solution, and another spoon cleaned. By alternating 
from one solution to the other in this way, any error in the time of 
cleaning, resulting from the metal becoming corroded, was distrib- 
uted equally between the two solutions. After removal from the 
cleaning solution the spoons were rinsed in cold water and wiped 
thoroughly dry with a soft cloth, rubbing very slightly. 
