infusorial earth

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]

from The Collaborative International Dictionary of English v.0.48

diatomaceous earth \di`a*to*ma"ceous earth`\ (Geol.),
   a deposit of fine, usually white, siliceous material,
   composed mainly of the shells of the microscopic plants
   called diatoms; also called {infusorial earth}, {kieselguhr},
   and {diatomite}. It is used in polishing powder, and in the
   manufacture of dynamite.
   [1913 Webster +PJC]