\Os"mic\, a. (Chem.)
Pertaining to, derived from, or containing, osmium;
specifically, designating those compounds in which it has a
valence higher than in other lower compounds; as, osmic
oxide.
{Osmic acid}. (Chem.)
(a) Osmic tetroxide. [Obs.]
(b) Osmic acid proper, an acid analogous to sulphuric acid,
    not known in the free state, but forming a well-known and
    stable series of salts (osmates), which were formerly
    improperly called osmites.
{Osmic tetroxide} (Chem.), a white volatile crystalline
   substance, {OsO4}, the most stable and characteristic of
   the compounds of osmium. It has a burning taste, and gives
   off a vapor, which is a powerful irritant poison,
   violently attacking the eyes, and emitting a strong
   chlorinelike odor. Formerly improperly called {osmic
   acid}.