from
The Collaborative International Dictionary of English v.0.48
Infusorial \In`fu*so"ri*al\, a. (Zool.)
Belonging to the Infusoria; composed of, or containing,
Infusoria; as, infusorial earth.
[1913 Webster]
{Infusorial earth} (Geol.), a deposit of fine, usually white,
siliceous material, composed mainly of the shells of the
microscopic plants called diatoms; also called
{diatomaceous earth}, {kieselguhr}, and {diatomite}. It is
used in polishing powder, and in the manufacture of
dynamite.
[1913 Webster +PJC]