The history and chemistry of the Murexide dye
|The whole course of the history of murexide was changed by the arrival of guano which was a source of uric acid.||The first cargo of Peruvian guano, imported as a fertiliser, was consigned to a Liverpool merchant in 1835; but in 1841 it was so little known that only 1700 tons were imported; six years later the importation amounted to 220,000 tons. The price in England was about £10 per ton. The uric acid content was initially about 20%, falling as the years went by and less rich deposits were mined to nearly zero. Guano was the key to the success of murexide as a dye.|
Preparation of uric acid from guano.
The guano is boiled with aqueous potassium hydroxide solution (10%) until all the ammonia is removed. Carbon dioxide is bubbled through the remaining liquid to give a precipitate of potassium hydrogen urate. This precipitate is filtered, washed with water and dissolved in sodium carbonate solution. The addition of hydrochloric acid gives a precipitate of uric acid.
|The first commercial manufacture of murexide started in 1853 at Mulhouse and within a year or two, Manchester. In Mulhouse Frédérick Sacc and Jules-Albert Schlumberger, both colorists from Alsace, promoted the use of murexide as a dye which was soon made by Depoully Frères and by Dolfus, Mieg et Cie. Shortly after production moved to Zuber at Rixheim on the eastern outskirts of Mulhouse. In Manchester, a major producer was Robert Rumney (1811-1872) at the Ardwick Chemical Works, Gorton. Around 1857-1859, he was processing 12 tons of guano a week, making 12 hundredweights of murexide which he sold for 30s per lb. The guano would have cost about £6,000 per year and sales of murexide brought in £100,000 for that period which is not a bad profit.|
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