342 The Art of Electro-plating and Gilding. 



easily prepared : — Dissolve in half a pint of clear rain water (or 

 distilled water) one ounce of cyanide of potassium, if any sedi- 

 ment subsides, decant the clear liquor and add one- eighth of an 

 ounce avoirdupois of oxide of silver; when the oxide is com- 

 pletely dissolved the liquid is ready for use. A gilding solu- 

 tion is made precisely in the same manner, merely substituting 

 oxide of gold for oxide of silver.* 



Supposing our solutions thus prepared, we may now arrange 

 our battery apparatus, which, it will be seen, is of an extremely 

 simple nature. Let a b be an ordinary preserve jar. Turn a 

 piece of common sheet zinc into the form shown at c d, and 

 attach to its upper edge the binding-screw G. Within the 

 cylinder of zinc, place a porous jar, sufficiently large to receive 

 the articles to be plated ; and over this place a binding- screw, 

 supported by the wire m. To the lower end of the wire n 

 attach the article to be plated, and fix the upper end in the 

 binding-screw h. In attaching the object to the wire n, con- 

 venience is the chief thing to be studied. I have obtained a 

 perfect coating to objects by soldering them to the wire, by 

 twisting the wire round them, or by binding the wire as in 

 fig. 2, and laying the coin upon it. In either case the con- 

 duction is sufficiently complete to answer every purpose. 



To set the apparatus in action, pour into the jar A b water 

 acidulated with sulphuric acid (1 acid to 30 water), and into 

 the porous vessel r as much of plating solution as will completely 

 cover the object. The apparatus may then be left to itself, and 

 in half an hour, or even less, the article will be covered with 

 silver — very thin, as may be supposed, but perfectly covered, if 

 all has been well managed. Thin as it is, however, it will be 

 sufficient for articles intended for the cabinet, as copies of coins 

 and medallions, or, indeed, any other object not subject to wear 

 and tear. For works of art exposed to the atmosphere and 

 dust, and which will, therefore, want occasional cleaning, a 

 thicker deposit will be required, and two hours would probably 

 be none too much for them; while in the case of spoons or 

 forks, four hours would be necessary. 



Were the experimenter not previously apprised of what he 



ought to expect, he would doubtless feel some astonishment on 



removing his medallion from the plating solution for the first 



time. Instead of a bright, sparkling, silvery surface, he would 



find a dirty- white, chalky-looking object, altogether unlike what 



he is aiming after; and though he might wash and wash again 



in water, the most he would accomplish by these means would 



be to render the surface of the object a little cleaner, though it 



* It is well to know that these oxides when sold by chemists who supply prac- 

 tical platers and gilders, arc obtained fully 25 per cent, cheaper than by those who 

 sell them merely for experimental purposes; a fact that may guide the tyro in the 

 choico of a shop. 



