Purification of Gum Arabic

Picciotto's process. The gum is dissolved in water, and sulphurous acid gas passed into it. The sulphurous acid is sufficiently removed for common purposes by gently boiling the mucilage in a retort with a receiver attached. But to obtain the gum in a purer state, carbonate of baryta is added, the mixture is filtered, afterwards agitated with gelatinous alumina, again filtered, and evaporated.

How To Stain Gun Barrels

(See Browning Liquids, further back.)

White Gun Powder

Well dried yellow prussiate of potash 1 part, white sugar 1 part, chlorate of potash 2 parts. Let the ingredients be separately reduced to a fine powder, and the powders mixed by the hand, or by means of a leathern barrel turning on its axis. Or they may be moistened with water, and granulated by passing the paste through a wire sieve.

How To Harden Gypsum

Keating's patent process is to moisten calcined gypsum with a solution of 1 lb. of borax, 1 lb. of tartar, in 11 lbs. of water; it is then heated to redness for 6 hours, and pulverized. Erdemann recommends plaster figures, etc, to be soaked in a solution of Fitch's soluble glass.

Hahnemann's Wine Test

See Tests.

Haeness Jet

Take 4 oz. best glue, 1 1/2 pints good vinegar, 2 oz. best gum arabic, 1/2 pint good black ink, 2 drs. best isinglass. Dissolve the gum in the ink, and melt the isinglass in another vessel in as much hot water as will cover it. Having first steeped the glue in the vinegar until soft, dissolve it completely by the aid of heat, stirring to prevent burning. The heat should not exceed 180°. Add the ink and gum, and allow the mixture again to rise to the same temperature. Lastly, mix in the solution of isinglass, and remove from the fire. When used, a small portion must be heated until fluid, and then applied with a sponge, and allowed to dry on.

Waterproof Paste for Harness

Put into a pipkin black resin 2 oz., place on a gentle fire, and when melted add bees'-wax 3 oz. When this is melted, remove from the fire, and stir in 1/2 oz. fine lamp-black and 1/2 dr. Prussian blue, finely powdered. when completely mixed, add spirits of turpentine to form a thin paste and let it cool. To be applied like blacking.

Heading for Beer

Equal parts of alum and sulphate of iron. - Gray.

Incense

See Perfumery.

Copying Ink

Mr. Brande directs 1 oz. of brown sugar to be added to No. 1, for copying. Another kind is made by dissolving 1/2 oz. of gum, and 20 grs. of Spanish liquorice, in 13 drs. of water, and adding to it a drachm of lamp-black, previously mixed with a teaspoonful of sherry. If the lamp-black is greasy, it should be heated to redness in a covered crucible. Another published form is: - Black ink 3 oz., sugar candy 1 oz.

Ink Powder

This consists of the dry ingredients for ink, powdered and mixed. 1. Powdered galls 4 oz., sulphate of iron (heated till it becomes white and pulverulent) 1 oz., powdered gum 1 oz., white sugar 1/2 oz.; mix. To make a quart of ink, with water or beer.

2. Powdered galls 2 lbs., green vitriol 1 lb., powdered gum 8 oz. In 2 oz. packets, each for 1 pint of ink. - Gray.