Important: Safety Warning
This page describes trade processes that use dangerously toxic materials such as cyanide solutions, mercury amalgams, or strong acids. These processes require training, equipment, and precautions far beyond what the text describes.
This information has been left in for historical purposes but should not be acted upon.
Soluble Glass
This alkaline silicate, known as water-glass, liquid quartz, etc., was discovered by Prof. Fuchs of Munich, 1825. It has the property of solubility in water, and may while in that state be applied to glass painting, waterproofing materials, restoration of decaying stone buildings, and as a binding element in artificial stone. When the water has evaporated it leaves a hard, gelatinous, transparent glass, which is impervious to water or destructive atmospheric changes. Mixed with metallic oxides it is a good paint for frescos, and also for commoner purposes. The solution is obtained by fusing together pulverized quartz 15, potash 10, and pulverized charcoal 1. This mass when cold is crushed, and boiled for three hours in five times its weight of water, taking care to supply what is lost by evaporation. The result is a viscid mass, which must be preserved in well-stoppered vessels. The glass may be diluted to suit whatever purpose it is employed for. Solvent for Gold.--Mix equal parts of nitric and muriatic acids. See GOLD; AQUA REGIA.
Soot is formed by the fuel which escapes combustion, and is composed principally of particles of carbon from a coal or wood fire. The lighter particles of ash are also mixed with it, as well as hydrocarbons from unburnt hydrocarbon vapors, and some ammoniacal salts. The latter qualities are what makes soot valuable as a manure. See CARBON.