The Collaborative International Dictionary of English v.0.48:

Semiglutin \Sem`i*glu"tin\, n. (Physiol. Chem.)
   A peptonelike body, insoluble in alcohol, formed by boiling
   collagen or gelatin for a long time in water. Hemicollin, a
   like body, is also formed at the same time, and differs from
   semiglutin by being partly soluble in alcohol.
   [1913 Webster]