The Natural Organic Colouring Matters
By
Arthur George Perkin, F.R.S., F.R.S.E., F.I.C., professor of colour chemistry and dyeing in the University of Leeds
and
Arthur Ernest Everest, D.Sc., Ph.D., F.I.C., of the Wilton Research Laboratories; Late head of the Department of Coal-tar Colour Chemistry; Technical College, Huddersfield
Longmans, Green and Co.
39 Paternoster Row, London
Fourth Avenue & 30th Street, New York
Bombay, Calcutta, and Madras
1918
Kaikki kuvat (kemialliset kaavat) puuttuvat // None of the illustrations (of chemical formulas) included.
Barwood is the wood of a large, fine tree, Baphia nitida (Lodd.), and is imported from the west coast of Africa, e.g. Sierra Leone, Angola, etc. In the log its physical properties are generally similar to those of sanderswood; in the rasped condition it has a somewhat brighter red colour and is devoid of aromatic odour. According to Girardin and Preisser, boiling water extracts about 7 per cent, of colouring matter, alcohol about 23 per cent., and hydrated ether about 19 per cent.
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When the crude colouring matter of barwood, dissolved in alcohol, is poured into ether the main bulk of the santalin is precipitated. The ethereal liquid now contains, in addition to a colouring matter resembling deoxysantalin, two crystalline substances identical with those previously stated by Weidel (loc. cit.) as present in sanderswood. To isolate santal the ether solution is treated with hydrobromic acid to remove colouring matter, the colourless crystalline residue remaining after evaporation is washed with benzene, and recrystallised first from dilute and subsequently from absolute alcohol.
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