What is "occlusion of gases"

Occlusion \Oc*clu"sion\, n. [See Occlude.]

1. The act of occluding, or the state of being occluded.

   Constriction and occlusion of the orifice.
   --Howell.

2. (Med.) The transient approximation of the edges of a natural opening; imperforation.
   --Dunglison.

   Occlusion of gases (Chem. & Physics), the phenomenon of absorbing gases, as exhibited by platinum, palladium, iron, or charcoal; thus, palladium absorbs, or occludes, nearly a thousand times its own volume of hydrogen, and in this case a chemical compound seems to be formed.