The Collaborative International Dictionary of English v.0.48:

Glassite \Glass"ite\, n.
   A member of a Scottish sect, founded in the 18th century by
   John Glass, a minister of the Established Church of Scotland,
   who taught that justifying faith is "no more than a simple
   assent to the divine testimone passively recived by the
   understanding." The English and American adherents of this
   faith are called Sandemanians, after Robert Sandeman, the
   son-in-law and disciple of Glass. Glass maker