THE SOLUTION.
In the tumbler is placed a solution consisting of two-thirds of a tumblerful of water, two ounces of bichromate of potash, and two ounces of sulphuric acid. The bichromate of potash should be dissolved first, then the acid should be slowly and carefully added. As the solution heats, it is well to prepare it in an earthen vessel, which is not liable to break. These materials should be used with great caution, as they are poisonous, and the solution is very corrosive, destroying almost everything with which it comes in contact. With proper care, however, there is no danger in using the solution. It gives off no poisonous vapors. Of course it is advisable to make the solution in quantities of a gallon or so when convenient.
The battery compound known as the C and C battery compound, sold in tin cans at most electric stores, is very convenient. It is only necessary to place two or three ounces of it in the tumbler and add the amount of water above mentioned, stirring the solution with a glass or rubber rod until the crystals are dissolved.
A caution is necessary here. If only a portion of the contents of the can are to be dissolved, it will be necessary to place the remainder in a glass or earthen jar, as it will absorb moisture and rapidly eat its way through the can.
The zinc plates should be amalgamated by plunging them into the bichromate solution, then sprinkling on a minute quantity of mercury, rubbing it about by means of a swab, until the entire exposed surface is covered with mercury.