The Collaborative International Dictionary
ammonium purpurate
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.