Relation of body mass index and waist-to-height ratio to cardiovascular disease risk factors in children and adolescents: the Bogalusa Heart Study. Freedman DS, Kahn HS, Mei Z, Grummer-Strawn LM, Dietz WH, Srinivasan SR, Berenson GS. [PubMed-indexed for MEDLINE].
Smelling salts release ammonia (NH3) gas, which triggers an inhalation reflex (that is, causes the muscles that control breathing to work faster) by irritating the mucous membranes of the nose and lungs. Although these hypothetical mechanisms have been discussed, it is likely that smelling salts are not effective.
Mackenzies smelling salts is popular and widely available in the UK.  They are quite out of fashion in the US.Hospitals use ammonia ampules. If you want to make some, finâ¦d a bottle with a 1/2 inch diameter opening. Fill 1/2 with rock salt, like pickling salt or ice cream salt.