Haemoscope

from The Collaborative International Dictionary of English v.0.48

Haemoscope \H[ae]m"o*scope\ (h[e^]m"[-o]*sk[=o]p or
   h[=e]"m[-o]-), n. [H[ae]mo- + -scope.] (Physiol.)
   An instrument devised by Hermann, for regulating and
   measuring the thickness of a layer of blood for spectroscopic
   examination.
   [1913 Webster]