FULMINATE, in chemistry, a salt of fulminic acid. Fulminate of mercury is prepared by dissolving 1 part of mercury in 12 parts of nitric acid; the solution is mixed with an equal volume of alcohol when cold. The mixture is then gently heated on a water bath. Red vapors are given off of nitrogen oxides and CO , and a large quantity of nitrous ether, alde hyde, and other products. When the liquid becomes turbid it is allowed to cool, and the salt separates out; it is purified by recrystallization from boiling water. It forms white needles, which, when heated to 186°, explode, also by friction or percussion when dry. It is used for charging percussion caps; one kilogram of mercury will make fulminate sufficient for 40,000 caps. Fulminates have been regarded as methyl cyanide in which one atom of hydrogen has been replaced by NO,, and two atoms of hy drogen by mercury or silver. The action of chlorine on mercuric fulminate under water forms chloropicrin, CCL (NO.), mercuric chloride HgCL, and cyanogen chloride CnCI. Hot nitric acid decom poses mercuric fulminate, yielding car bonic acid, acetic acid, and mercuric nitrate. Hydrochloric acid converts it into mercuric chloride and mercurous oxalate. When boiled with an aqueous
solution of potassium chloride it is con verted into potassium fulminurate.
Fulminate of silver is obtained by heating nitrate of silver with strong nitric acid and alcohol till the liquid boils up. It is very dangerous to prepare. It crystallizes in small, white, opaque needles; it is very poisonous, and ex plodes by friction or percussion, or when heated. It is soluble in aqueous ammonia, and deposits the fulminate unaltered. When silver fulminate is digested with water and metallic copper or zinc, the silver is replaced and copper fulminate or zinc fulminate is obtained. When ful minate of copper is mixed with ammonia, and a stream of H C gas is passed through the solution, the copper is com pletely precipitated, and the filtered solu tion contains hydrosulphocyanic acid and urea. Fulminate of gold was discovered by a monk in the 15th century. This substance, which explodes more rapidly and with greater local force than gun powder, is made by precipitating a solu tion of chloride of gold by an excess of ammonia.