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PLATING.

in a state of minute division to the clean surface of the copper,and afterwards to fix it there by fusion; and accordingly thissilvering may be effected by using the argentine precipitate herementioned with supersaturated borate of soda, or mercury, andcausing it to adhere by fusion.

The dial plates of clocks, the scales of barometers and othersimilar articles are silvered by rubbing upon them a mixture ofmuriate of silver, muriate of soda, and acidulous tartrite ofpotash, and afterwards carefully washing off tire saline matterwith water. In this operation the silver is precipitated from themuriatic acid, which unites with part of the coppery surface. Itis not durable, but may be improved by heating the article, andrepeating the operation till the covering seems sufficiently thick.'

Shell-silver for the use of painters is prepared by trituratingsilver-leaf with a little honey or mucilage of gum arabic in amortar; and afterwards separating the honey or gum by meansof water. When the honey or gum is washed away the silvermay be put on paper or kept in shells, whence its name. Whenit is to be used it must again be diluted with gum-water.

Remark. ..The application of silver-leaf for silvering paper,wood, See. is analogous to the application of gold-leaf which willbe noticed circumstantially in the next part.

PLATING.

The covering of the surface of copper with silver or plating isperformed in the following manner: Upon small ingots of cop-per, plates of silver are bound with iron wire, generally allow-ing one ounce of silver to twelve ounces of copper. The surfaceof the plate of silver is not quite so large as that of the copperingot. Upon the edges of the copper which are not covered bythe silver, a little borax is put, and by exposing the whole to astrong heat, the borax melts, and in melting contributes to fusethat part of the silver to which it is contiguous, and to attachit in that state to the copper. The ingot, with its silver