In movies and action TV shows, they show people who are unconscious.
Then someone will say "Wake them up." Then someone will go over to the
unconscious person and snap something under their nose. When this
happens the person wakes up. This happens in many movies and TV shows
so I think there is really something that can be released under
someone's nose to bring them back to consciousness. I would like to
know what that is and how it works, and if it smells really bad?
Thanks.

Hello.

You're talking about "smelling salts."

"Smelling salts" contain ammonia, and have been used to revive someone
who has fainted.  The odor is reportedly very pungent.

"Almost everyone has smelled the sharp, penetrating odor of ammonia,
NH3. As the active product of "smelling salts," the compound can
quickly revive the faint of heart and light of head. But more than a
sniff of this toxic, reactive, and corrosive gas can make one very ill
indeed. It can, in fact, be fatal. Ammonia is pretty nasty stuff. "
source: University of Wisconsin: Chemical of the Week - Ammonia
http://scifun.chem.wisc.edu/chemweek/Ammonia/AMMONIA.html

From the BBC:
" A stricken Tim Henman turned to smelling salts to help revive his
fortunes at Wimbledon.
 The crystals, in Victorian tradition an effective method of helping
ladies who had fallen prey to fainting fits, are wafted under the
nose.
They release ammonia gases which irritate the linings of the nose and
lungs, triggering a reflex which increases breathing rate, and as a
result, alertness."
http://212.58.226.40/1/hi/health/2082231.stm

Also see:
"Ask A Scientist: Smelling Salt Fabrication"
http://www.newton.dep.anl.gov/askasci/chem03/chem03114.htm


Some physicians feel that "smelling salts" (ammonia inhalants) are unsafe. See:
"Stop sale, use of 'smelling salts'"
http://www.aafp.org/fpr/20041200/letters.html

Also see eMedicine.com:
"Smelling salts are a less common source of household ammonia
ingestion. Often in capsule form, smelling salts, which contain
approximately 20% ammonia, release a pungent odor when broken.
Smelling salts are found in many first-aid kits as a treatment for
syncope; unfortunately, children sometimes bite into them, resulting
in minor esophageal burns and mild respiratory symptoms."
http://www.emedicine.com/emerg/topic846.htm

Smelling salts available for sale in the U.S.:
http://www.familymeds.com/froogle/product.asp?sku=30395007392
http://www.first-aid-product.com/industrial/ammonia-inhalants.htm

---------
search strategy:
"smelling salts"
"smelling salts" ammonia
"smelling salts" ammonium

I hope this helps.

Wow. Thank you very much. Thats was exactly the answer I was looking
for. I tried searching for it but I could not find it casue I did not
know what to google. Thanks.

I had a capsule of ammonia snapped under my nose once when I was in a
hospital, parked in a traffic jam of gurneys and wheelchairs, awaiting
treatment.  I don't know what happened, but I was suddenly jolted by
this very strong, acrid odor that made my eyes sting.  I uttered some
sort of exclamation and jerked my head away.  I must not have been
completely out because I was aware of the snap just before the fumes
hit.  Gack.  I would prefer not to do that again.

I remember asking to be shown what it was they had used and have it
explained to me.  The nurse showed me an unopened capsule that I think
she had in her pocket.

Archae0pteryx

Zappa:
Thank you for the tip.
-juggler