• Webster's Revised Unabridged Dictionary
    • n Murexide (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.
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Century Dictionary and Cyclopedia
    • n murexide The purpurate of ammonia of Prout (probably C8H8N6O6). It crystallizes in four-sided prisms, two faces of which reflect a green metallic luster. The crystals are transparent, and by transmitted light are of a garnet-red color. It forms a brownish-red powder, and is soluble in caustic potash, the solution having a beautiful purple color. In 1855 and 1856 this substance was largely used as a dye for producing pinks, purples, and reds, but the introduction of aniline colors put an end to its use.
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Webster's Revised Unabridged Dictionary
L. murex, the purple fish, purple


In literature:

It is not there: I find not the least trace of murexide.
"The Wonders of Instinct" by J. H. Fabre
The first group comprises madder, cochineal, orchil, alkanet, and murexide.
"Scientific American Supplement, No. 363, December 16, 1882" by Various
Look for any signs of work on the surface ... chisel marks, Murexide charges, anything.
"Gold in the Sky" by Alan Edward Nourse
It is not there: I find not the least trace of murexide.
"The Glow-Worm and Other Beetles" by Jean Henri Fabre