smelling salts, also known as spirit of hartshorn or sal volatile, are chemical compounds used for arousing consciousness. the usual active compound is ammonium carbonate, a colorless-to-white, crystalline solid ((nh4)2co3). because most modern solutions are mixed with water, they should more properly be called "aromatic spirits of ammonia." modern solutions may also contain other products to perfume or act in conjunction with the ammonia, such as lavender oil or eucalyptus oil. ==history== smelling salts have been used since roman times and are mentioned in the writings of pliny as hammoniacus sal. evidence exists of use in the 13th century by alchemists as sal ammoniac. in the 17th century, the distillation of an ammonia solution from shavings of harts' (deer) horns and hooves led to the alternative name for smelling salts as spirit or salt of hartshorn. smelling salts have also been known as 'sal volatile', for their ability to produce ammonia vapour. they were widely used in victorian britain to revive fainting women, and in some areas constables would carry a container of them for the purpose. the use of smelling salts was widely recommended during the second world war, with all workplaces advised by the british red cross and st. john ambulance to keep 'sal volatile' in their first aid boxes. nowadays, their use and prevalence has dramatically decreased. ==usage== smelling salts are often used on athletes (such as boxers) when they are knocked unconscious or semi-conscious to arouse consciousness and restore mental alertness. they are also used in competitions (such as powerlifting, strong man and ice hockey) to "wake up" competitors to perform better. famous athletes such as tyler seguin, brett favre, peyton manning, carlos boozer, samuel eto'o, and tom brady have been seen using smelling salts on the sidelines.{{cite web|last=freeman|first=mike|title=a whiff of trouble?|url=http://jacksonville.com/tu-online/stories/020305/sup_17863663.shtml|publis
Ammonium_compounds First_aid