=Fulminates.= These are the most powerful and dangerous explosives in common use. They consist for the most part of metallic salts of fulminic and amic acids. The commonest fulminate, known as mercury fulminate, is formed by dissolving mercury in nitric acid, to which solution when cool is added 110 parts of alcohol. Water is then added, causing a grey fulminate to precipitate. This is carefully washed and air-dried. The operation is attended with great danger. The color of fulminate varies from a white to dirty grey. Its specific gravity is 4.42 deg. F. It has a sweetish taste and is highly poisonous. It is extremely sensitive to heat and shock of every kind. Its firing point when slowly heated is 306.5 deg. F., and when rapidly heated 368.6 deg. F. When wet it is less sensitive, but not secure against explosion. The slightest friction will provoke its explosion. It may be destroyed safely by treating it with alkaline sulphides. Fulminates of other metals are capable of being made, such as fulminates of silver, gold, platinum, zinc and copper, but these are more violently exploded and less stable. The only one which has come into any use being a silver compound. Mercury fulminate is the explosive used in the manufacture of detonators. (See page 89, Manual of Field Engineering, 1911.) =Detonators and Fuses.= (See pages 89, 90 and 91, Manual of Field Engineering, 1911.) =Theory of Explosives and Fumes. Definition of Explosive=: Explosive is a substance either solid, liquid, or jelly, which, when subjected to a shock, suddenly changes from solids, etc., to gases, at a very high temperature, tearing to pieces any vessel which may contain them.