The Collaborative International Dictionary of English v.0.48:

Haematosin \H[ae]m`a*to"sin\ (h[e^]m`[.a]*t[=o]"s[i^]n or
   h[-e]*m[a^]t"[-o]*s[i^]n), n. (Physiol. Chem.)
   Hematin. [R.]
   [1913 Webster]