I

Aluminum articles are very hard to clean so they will have a bright, new appearance. This is especially the case with the matted or frosted pieces. To restore the pieces to brilliancy place them for some time in water that has been slightly acidulated with sulphuric acid.

II

Wash the aluminum with coal-oil, gasoline or benzine, then put it in a concentrated solution of caustic potash, and after washing it with plenty of water, dip it in the bath composed of J nitric acid and 1/3 water. Next, subject it to a bath of concentrated nitric acid, and finally to a mixture of rum and olive oil. To render aluminum capable of being worked like pure copper, 2/3 of oil of turpentine and 1/3 stearic acid are used. For polishing by hand, take a solution of 30 parts of borax and 1,000 parts of water, to which a few drops of spirits of ammonia have been added.