\He"min\, n. [Gr. a"i^ma blood.] (Physiol. Chem.)
A substance, in the form of reddish brown, microscopic,
prismatic crystals, formed from dried blood by the action of
strong acetic acid and common salt; -- called also
Teichmann's crystals. Chemically, it is a hydrochloride of
hematin.
Note: The obtaining of these small crystals, from old blood
      clots or suspected blood stains, constitutes one of the
      best evidences of the presence of blood.