8.12.24

Heather or Calluna vulgaris
(CHAPTER VII. Flavonol Group.)

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.

In former times the common heath or heather, until recently named Erica vulgaris, was used as a dyestuff for producing a yellow colour on - woollen goods (Crookes, "Dyeing and Calico Printing," 1874, p. 511). Although now almost superseded it was until recently employed in the home industries of outlying districts, such as the Highlands of Scotland. Bancroft ("Philosophy of Permanent Colours," 1813, 2, 1 08) states that all five species of the erica or heather found in Great Britain are, he believes, capable of giving yellows much like those obtained from dyer's brown. According, however, to the experiments of the late J. J. Hummel the E. tetralix (bell heather) and E. cinerea contain only traces of yellow colouring matter. Leuchs (Farben u. Färbekunde, 2, 320) refers to the tanning property of heather, and notes that the effect resembles in character that given by oak bark. H. R. Procter found it to contain 6.4 per cent, of tannin. The colouring matter was isolated by Perkin and Newbury (Chem. Soc. Trans., 1899, 75, 837) from an aqueous extract of the green portion of the plant, in which it appears only to reside, by precipitation with lead acetate in the usual manner. It proved to be identical with the quercetin of quercitron bark. The dyeing properties of heather, though distinctly weaker, are so similar in character to those given by quercitron bark as to require no special description. Experiment showed that 36 parts of the heather were necessary to obtain as good a result as that given by 10 parts of quercitron bark.

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