To test the enamel of ordinary kitchen utensils for the presence of lead, apply a drop of concentrated nitric acid to the enamel of the vessel, first carefully cleaning same, and evaporate it until dry, with a moderate heat. Then wet the place, subject it to the action of the acid with a drop of sodium iodide, and if there is lead present a yellow iodide of lead will be formed.
This polish is made by the dissolution, in 2 parts of water (soft), of 2 parts of Castile soap. The resultant paste is stirred into 6 parts of fine whiting, poured into molds and cooled. If it is desired that this soap should have a rose tinge, substitute for the whiting 2 parts (finest quality) white tripoli, 1 part jewelers' rouge and 3 parts pulverized chalk. Perfume the soap before putting it into the molds with a drop or two of oil of Lavender, which gives it a very dainty odor.
66 2-10 parts Copper, 33 1-10 parts Zinc. 7-10 parts Iron.
Mix 1 ounce sulphate of copper, 1/2 ounce of alum, and 1/2 teaspoonful of salt reduced to powder, with 1 gill of vinegar and 20 drops of nitric acid. This liquid may be used for either eating deeply into the metal or for imparting a beautiful frosted appearance to the surface, according to the time it is allowed to act. Cover the parts you wish to protect from its influence with beeswax, tallow or some other similar substance.
For etching on glass, prepare the glass by warming it and rubbing white wax over it until the surface is covered thinly. Trace the design through the wax with a pointed instrument. Pour on liquid fluoric acid and leave to act upon the glass; this will make a clean, transparent cut. To produce opaque lines, like ground glass or frosted work, place the fluoric acid in a lead utensil and place in hot sand, or in some way warm the acid without melting the lead pan. Place the prepared glass over the pan, and the fumes from the acid will act upon the glass. This should be done out of doors or in some place where the fumes will not be inhaled. A simple method of the process is to wet the prepared glass with sulphuric acid and then sprinkle on finely powdered flour spar (Fluoride of calcium), by which hydrofluoric acid is set free and attacks the glass.
The process is similar to that used by engravers. Acid is spread over the part to be etched, then the figures or name is cut on with a needle-point, and the acid and cold bath finishes the work.
To fasten asbestos to iron use billsticker's paste; prepared asbestos, which comes in cans, will adhere of itself when it dries.
A material for fastening knives or forks into their handles when they have become loosened by use, is a much-needed article. The best cement for this purpose consists of 1 pound of colophony (purchasable at the druggist's), and 8 ounces of sulphur, which are to be melted together, and either kept in bars or reduced to a powder. One part of the powder is to be mixed with half a part of iron filings, fine sand, or brickdust, and the cavity of the handle is then to be filled with this mixture. The stem of the knife or fork is then to be heated and inserted into the cavity, and when cold it will be found fixed in its place with great tenacity.