I

Articles of polished copper, such as clocks, stove ornaments, etc., become tarnished very quickly. To restore their brilliancy dip a brush in strong vinegar and brush the objects to be cleaned. Next pass through water and dry in sawdust. A soap water, in which some carbonate of soda has been dissolved, will do the same service.

II

This is recommended for machinery by the chemical laboratory of the industrial museum of Batavia:

Oil of turpentine..... 15 parts

Oil of stearine....... 25 parts

Jewelers' red........ 25 parts

Animal charcoal, of superior quality.... 45 parts

Alcohol is added to that mixture in such a quantity as to render it almost liquid, then by means of a brush it is put on those parts that are to be polished. When the alcohol has dried, the remaining cover is rubbed with a mixture of 45 parts of animal charcoal and 25 parts jewelers' red. The rubbed parts will become quite clean and bright.

III

The ugly spots which frequently show themselves on nickel-plated objects may be easily removed with a mixture of 1 part sulphuric acid and 50 parts alcohol. Coat the spots with this solution, wipe off after a few seconds, rinse off thoroughly with clean water, and rub dry with sawdust.

IV

Crocus, dried and powdered, when applied with chamois leather to nickel-plated goods, will restore their brilliancy without injuring their surface.

V

Articles of tin should be ground and polished with Vienna lime or Spanish white. The former may be spread on linen rags, the latter on wash leather. Good results may be obtained by a mixture of about equal parts of Vienna lime, chalk, and tripoli. It should be moistened with alcohol, and applied with a brush. Subsequent rubbing with roe skin (chamois) will produce a first-rate polish. Tin being a soft metal, the above polishing substances may be very fine.

VI

To polish watch cases, take two glasses with large openings, preferably two preserving jars with ground glass covers. Into one of the glass vessels pour 1 part of spirit of sal ammoniac and 3 parts water, adding a little ordinary barrel soap and stirring everything well. Pill the other glass one half with alcohol. Now lay the case to be cleaned, with springs and all, into the first-named liquid and allow to remain therein for about 10 to 20 seconds. After protracted use this time may be extended to several minutes. Now remove the ease, quickly brush it with water and soap and lay for a moment into the alcohol in the second vessel. After drying off with a clean cloth heat over a soldering flame for quick drying and the case will now look almost as clean and neat as a new one. The only thing that may occur is that a polished metal dome may become tarnished, but this will only happen if either the mixture is too strong or the case remains in it too long, both of which can be easily avoided with a little practice. Shake before using.

VII

This is a cleanser as well as polisher:

Prepared chalk......... 2 parts

Water of ammonia...... 2 parts

Water sufficient to make. 8 parts

The ammonia saponifies the grease usually present.

It must be pointed out that the alkali present makes this preparation somewhat undesirable to handle, as it will affect the skin if allowed too free contact.

The density of the liquid might be increased by the addition of soap; the solid would, of course, then remain longer in suspension.

VIII

Serviettes Magiques.—These fabrics for polishing articles of metal consist of pure wool saturated with soap and tripoli, and dyed with a little coralline. They are produced by dissolving 4 parts of Marseilles soap in 20 parts of water, adding 2 parts of tripoli and saturating a piece of cloth 3 inches long and 4 inches wide with it, allowing to dry.

IX

In order to easily produce a mat polish on small steel articles use fine powdered oil stone, ground with turpentine.