from
The Collaborative International Dictionary of English v.0.48
Murexide \Mu*rex"ide\, 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]