Smelling salts, also known as ammonia inhalants, spirit of hartshorn, or sal volatile, are chemical compounds used as stimulants to restore consciousness after fainting.
[6] They are also used as a form of stimulant in athletic competitions (such as powerlifting, strong man, rugby and ice hockey) to "wake up" competitors to perform better.
[1] They were widely used in Victorian Britain to revive fainting women, and in some areas, constables would carry a container of them for that purpose.
[10] At that time, smelling salts were commonly dissolved with perfume in vinegar or alcohol and soaked onto a sponge, which was then carried on the person in a decorative container called a vinaigrette.
[7] Fainting can be caused by excessive parasympathetic and vagal activity that slows the heart and decreases perfusion of the brain.