412 ECONOMIC AND TECHNICAL 



used to dye wool, etc., and Pliny in his Phycos Thalassion is also under- 

 stood as referring to the lichen Roccella, "with crisp leaves, used in Crete for 

 dyeing garments." 



Information as to the dyeing properties of certain lichens is given in most 

 of the books or papers dealing with these plants from the herbals onwards. 

 Hoffmann^ devoted a large part of his Commentatio de vario Lichenum usu 

 to the dye-lichens, and, illustrating his work, are a series of small rectangular 

 coloured blocks representing samples of woollen cloth dyed with different 

 lichens. There are seventy-seven of these "samples with the colour names 

 used by French dyers. 



An important treatise on the subject translated into French was also 

 contributed by Westring^. He desired to draw attention to the tinctorial 

 properties of lichens other than the Roccellae which do not grow in Sweden. 

 The Swedes, he states, already used four to six lichens as dye-plants, but 

 only for one colour. He demonstrated by his improved methods that other 

 colours and of finer tint could be obtained. He describes the best methods 

 both of extraction and of dyeing, and then follows with an account of the 

 different lichens likely to be of service. The treatise was subsequently 

 published at greater length in Swedish" with twenty-four very fine coloured 

 illustrations of the lichens used, and with sample blocks of the colours to be 

 obtained. 



b. The Orchil Lichen, Roccella. The value of Roccella as a dye- 

 plant had been lost sight of until it was accidentally rediscovered, early in 

 the fourteenth century, by a Florentine merchant called Federigo. He intro- 

 duced its use into Florence, and as he retained the industry in his own hands 

 he made a large fortune, and founded the family of the Orcellarii, called 

 later the Rucellarii or Rucellai, hence the botanical name, Roccella. The 

 product was called orseille for which the English name is orchil or archil. 

 Another origin suggested for orchil is the Spanish name of the plant, 

 Orcigilia. There are a number of different species that vary in the amount 

 of dye-product. Most of them grow on rocks by the sea-side in crowded 

 bluish-grey or whitish tufts of strap-shaped or rounded stiff narrow fronds 

 varying in length up to about six inches or more. The main supply of 

 "weeds" came from the Levant until the fifteenth century when supplies 

 were obtained from the Canaries (long considered to produce the best 

 varieties), Cape Verd and the African coasts. The geographical distribution 

 of the Roccellae is very wide : they grow on warm sea-coasts all over the 

 globe, more particularly in Angola, the Cape, Mozambique, Madagascar, in 

 Asia, in Australia, and in Chili and Peru. 



Zopf* has proved the existence of two different colouring substances 

 among the Roccellas : in R. fuciformis (Fig. 57) and R. fucoides (both 



' Hoffmann 1787. " Westring 1792 and 1793. ' Westring 1805-1809. ■* Zopf 1907. 



