Objects of polished copper, bronze, brass, and other alloys of copper tarnish through water and it is sometimes necessary to give them again their bright appearance. Pickle the articles in an acid bath; wash them next in a neutral bath; dry them, and subsequently rub them with a polishing powder. Such is the general formula; the processes indicated below are but variants adapted to divers cases and recommended by disinterested experimenters:

Sharp Polishes

The following three may be used on dirty brasses, copper articles, etc., where scratching is not objectionable:

I

Quartz sand, powdered and levigated.............. 20 parts

Paris red.......... 30 parts

Vaseline........... 50 parts

Mix intimately and make a pomade.

II

Emery flour, finest levigated........   50 parts

Paris red..........   50 parts

Mutton suet........   40 parts

Oleic acid.........   40 parts

III

Levigated emery powder........   100 parts

Anhydrous sodium carbonate......       5 parts

Tallow soap.......     20 parts

Water............   100 parts

Copper Articles

Make a mixture of powdered charcoal, very fine, 4 parts; spirit of wine, 3 parts; and essence of turpentine, 2 parts. To this add water in which one-third of its weight of sorrel salt or oxalic acid has been stirred, and rub the objects with this mixture.

Bronze Articles

Boil the objects in soap lye, wash in plenty of water, and dry in sawdust.

Highly Oxidized Bronzes

First dip in strong soda lye, then in a bath containing 1 part of sulphuric acid to 12 parts of water. Rinse in clean water, and next in water containing a little ammonia. Dry and rub with a polishing powder or paste.