Almost any wood can be dyed black by the following: means: Take logwood extract, powder 1 ounce and boil it in 3 1/4 pints of water; when the extract is dissolved, add 1 drachm potash yellow chromate (not the bichromate), and agitate the whole. The liquid will serve equally well to write with or to stain wood. Its color is a very fine dark purple, which becomes a pure black when applied to the wood.
Stannic sulphide is obtained by passing through a heated tube sulphurated hydrogen and stannic chloride. It can also be made by heating mixtures of corrosive sublimate and stannic sulphide.
The mixture for steel-gray coating is prepared as follows: Triturate 3 85-100 grains of lamp-black with 3 drops of gold-size oil in a dish to a homogeneous cohering mass and dilute this with 24 drops of oil of turpentine. Apply with fine brush in very thin and uniform layers and allow to dry thoroughly.
1 pound Strong Hydro-Chloric Acid,
1 pint of Water, to which the addition is made of:
5 1/4 ounces Pulverized Antimonic Sulphide, 5 3/4 ounces Pulverized Iron Filings.
(2) Another mixture for this purpose is composed of hydro-chloric acid compounded with arsenious acid. This compound is put in a lead vessel and the objects immersed in it should be brought in touch with the leaden sides of the vessel or should be enwrapped with a strip of lead.
In order to give copper a steel-gray color the articles are to be cleaned and pickled in a heated solution of chloride of antimony in hydro-chloric acid. By the use of a strong galvanic current a coating with a steel-gray precipitation of arsenic may be given the articles by putting them in a heated arsenic bath. If it is desired to give copper a dark, steel-gray color a good pickle consists of 1 quart of hydro-chloric acid, 1/8 quart nitric acid, 1 1/2 ounces iron filings, 1 1/2 ounces arsenious acid.
In order to give a ground steel object the appearance of gold or good bronze, the first step is in removing all dirt from the same by a bath in benzine, petroleum or 'turpentine. It is then to be heated and a light gold varnish applied, which on drying is to be coated with the best copal lacquer.
Sterro-metal is composed of:
Talmi gold is a copper-zinc alloy composed of:
86 4-10 parts Copper, 12 2-10 parts Zinc, 1 1-10 parts Tin, 1 3-10 parts Iron.
Tartar emetic is made by boiling cream of tartar with tetroxide of antimony until its dissolution.
To temper magnets, use a water-tight vessel, with two soft-iron pole pieces at the bottom. Place underneath these the poles and electro-magnet. Partially till the vessel with water, and put a layer of oil above this. Plunge the red-hot bar through these. It will be found that its prior passage through the oil will soften the steel without demagnetization.