concrete oil of wine

from The Collaborative International Dictionary of English v.0.48

Etherin \E"ther*in\, n. (Chem.)
   A white, crystalline hydrocarbon, regarded as a polymeric
   variety of ethylene, obtained in heavy oil of wine, the
   residue left after making ether; -- formerly called also
   {concrete oil of wine}.
   [1913 Webster]