What is "smelling bottle"

Smelling \Smell"ing\, n.

1. The act of one who smells.

2. The sense by which odors are perceived; the sense of smell.
   --Locke.

   Smelling bottle, a small bottle filled with something suited to stimulate the sense of smell, or to remove faintness, as spirits of ammonia.

n. a bottle containing smelling salts