[ 91 J 



IV. 



ON THE TINCTOEIAL CONSTITUENTS OF SOME LICHENS 

 WHICH ABE USED AS DYES IN lEELAND. 



By HUGH EYAN, D.Sc, and W. M. O'EIOEDAN, M.Sc, 

 University College, Dublin. 



Read NovEMBEU 30, 1916. Published Febuuakv 6, 1917. 



The use of certain species of Lichens for producing purple or blue dyes — 

 Archil and Litmus — has been known in many European countries for a 

 long time, the discovery of these dyes being said to be due to a Plorentine 

 named Frederigo about 1300 a.d. 



Besides these dyes, the inhabitants of Ireland, Scotland, and other parts 

 of Northern Europe, have long been acquainted with the use of certain other 

 species of Lichens for dyeing wool various shades of yellow or reddish-brown. 

 Thus, in "The Antient and Present State of the County and City of Cork," 

 by Charles Smith, m.d. (Dublin, 1749), it is stated (vol. ii, p. 360) that 

 Lichenoides tatareum lividum scuttellis rufis, or red-spangled lichenoides, 

 which was found on rocks at Eathpeean, Co. Cork, dyes wool a lemon colour. 

 Again, in an "Essay towards a Natural History of the County of Dublin," 

 by John Eutty, m.d. (Dublin, 1772), it is mentioned in vol. i, p. 138, that 

 Lichen petraeus Derhiensis, also called Coi'k or Corker, was used for dyeing 

 wool a brown-reddish colour, and also for compound dyeing. On page 140 

 of the same volume it is stated that Lichenoides crustafoliosa, which, it is 

 said, was probably identical with the stone-crotal of the north of Ireland, 

 was used in this country and in the Isle of Man to dye woollen cloth an 

 orange colour. When serge was heated in a mixture of the lichen with 

 water, it acquired a lemon colour. Again, on page 141 it is mentioned that 

 Lichenoides pulmoneum reticukdum, called Hazel- rag or Hazel-crottles in the 

 North of Ireland, on boiling with wool in water imparts a durable orange 

 colour to the wool. Further, in the Introduction to O'Curry's " Manners and 

 Customs of the Ancient Irish" (page cccci), W. K. Sullivan states that, 

 amongst others, two species of lichen, called Crotal, Parmelia saxatilis Ach. 



R.I. A. PROC, VOL. .'i.KXIII, SECT. B. [Pj 



