. Lichens. Lichens. 4it ECONOMIC AND TECHNICAL various dye-species, and Hoffmann, as already stated, gives illustrations of colours that can be obtained. It has been once and again affirmed that Parmelia saxatilis yields a red colour, but Zopf denies this. It contains saxatillic acid which is colourless when extracted but on boiling gives a clear reddish-yellow to reddish-brown solution which dyes wool and silk directly without the aid of a mordant. ZopP observed the process of dyeing. 'U\ :_«*-:_. Fig. 135. Parmelia omphalodes Ach. (S. H., ;). followed in South Tyrol: a layer of th
. Lichens. Lichens. 4it ECONOMIC AND TECHNICAL various dye-species, and Hoffmann, as already stated, gives illustrations of colours that can be obtained. It has been once and again affirmed that Parmelia saxatilis yields a red colour, but Zopf denies this. It contains saxatillic acid which is colourless when extracted but on boiling gives a clear reddish-yellow to reddish-brown solution which dyes wool and silk directly without the aid of a mordant. ZopP observed the process of dyeing. 'U\ :_«*-:_. Fig. 135. Parmelia omphalodes Ach. (S. H., ;). followed in South Tyrol: a layer of the lichen was placed in a cooking pot, above this a layer of the material to be dyed, then lichen and again the material until the pot was filled. It was covered with water and boiled three to four hours, resulting in a beautiful rust-brown and peculiarly fast dye. Reddish- or rust-brown dye is^lso obtained from Haematomma ventosum and H. coccineum, a yellow-brown from Parmelia conspersa (salazinic acid), and other shades of brown from Parmelia perlata, P. physodes, Lobaria pul- monaria and Cetraria islandica. Yellow lichens in general furnish yellow dyes, as for instance Xanthoria parietina which gives either brown or yellow according to treatment and Cetraria juniperina which forms a beautiful yellow colouring substance on ' Zopf Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Smith, Annie Lorrain. Cambridge, At the University Press
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