GNU Collaborative International Dictionary of English

Found one definition

1.       
   Murexide (?), n. [L. murex the purple fish, purple.] (Chem.) A crystalline nitrogenous substance (C8H8N6O6, 5-5'-nitrilodibarbituric acid monoammonium salt) having a splendid dichroism, being green by reflected light and garnet-red by transmitted light.  It was formerly used in dyeing calico, and was obtained in a large quantities from guano.  It is now synthesized from alloxan.  Formerly called also ammonium purpurate.
   
   [1913 Webster +PJC]