To correct any bad smell which may arise in a tin-shop place coffee in an iron vessel over the fire, close all doors and windows, and let the coffee burn until the room is thoroughly impregnated with the same. Let the room remain closed a short time, and when opened again it will be fresh and wholesome again in a few minutes. It is an excellent thing in cases of sickness, where fevers cause offensive smells.
Corrosive sublimate is obtained by the dissolution of mercury in aqua regia. It is very poisonous.
The following receipt produces a cheap and simple non-conducting covering for steam pipes: Four parts coal ashes, sifted through a riddle of four meshes to the inch; 1 part calcined plaster; 1 part flour; 1 part fire clay. Mix the ashes and fire-clay together to the thickness of thin mortar, in a mortar-trough; mix the calcined plaster and flour together dry, and add to it the ashes and clay as you want to use it; put it on the pipes in two coats, according to the size of the pipes. For a six-inch pipe put the first coat about 1 1/4 inches thick; the second coat should be about 1/2 inch thick. Afterwards finish with hard finish, same as applied to plastering in a room. About 2 1/2 hours will be required to set on a hot pipe.
A refractory crucible can be made by compounding 1 part of quartz sand with 2 parts pipe-clay. The latter, however, must be very fine.
Cuivre fume is made by coloring copper blue-black with a solution of liver of sulphur, then rinsing same and brushing with a scratch brush, this making a shade lighter. The raised portions which are to show the color of copper are polished on a disk in order to remove the coloration.
Cupric chloride is obtained by the dissolution of cupric oxide in hydro-chloric acid and the subsequent evaporation of same.
Cupric sulphate, better known as blue vitriol, or as sulphate of copper, dissolves in 4 parts of cold water. To obtain same dissolve cupric oxide in sulphuric acid.
Cyanide of gold is prepared by precipitation of a solution of chlorate of gold with a solution of cyanide of potassium.
To give a dead black finish to copper brush same with a compound of 1 part platinum chloride and 5 of water, and, after drying, rub with a flannel rag wet with a drop of oil. The copper can also be immersed in a solution of manganese or nitrate of copper and dried over a coal fire. This operation is to be repeated until the desired color is obtained.
Delalot's alloy is composed of:
2 parts Manganese, 18 parts Zinc,
1 part Phosphate of Lime, 80 parts Fine Copper.
The copper is first melted and then the manganese is gradually added, and after its complete dissolution the phosphate of lime is added. The scoria is removed and the zinc is added about ten minutes before casting. The fusion from the manganese will be facilitated by the addition of 1 part charcoal, 1/2 part borax and 1/2 calcium fluoride.