The Collaborative International Dictionary of English v.0.48:

Bacterioscopy \Bac*te`ri*os"co*py\
   (b[a^]k*t[=e]`r[i^]*[o^]s"k[-o]*p[y^]), n. [Bacterium +
   -scopy; fr. Gr. bakth`rion, ba`ktron, a staff + skopei^n to
   view.] (Biol.)
   1. The application of a knowledge of bacteria for their
      detection and identification, as in the examination of
      polluted water.
      [1913 Webster]

   2. Microscopic examination or investigation of bacteria. --
      Bac*te`ri*o*scop"ic, a. -- *scop"ic*al*ly, adv. --
      Bac*te`ri*os"co*pist, n.
      [Webster 1913 Suppl.]