TKANSACTIONS OF THE SECTIONS. 39 



8. It is impossible to foretell or estimate the colorific value of any given new sam- 

 ple of " orchella weed " by any tests or series of chemical or other experiments 

 on the small scale. It can be determined only by manufacture on the large scale ; 

 and as this is an experiment that necessarily involves the risk of heavy pecu- 

 niary loss, it is not surprising that new materials and new processes are 

 accepted or adopted with unusual tardiness or caution. 



9. The substitution, as an article of import, of the colorijic principles for the 

 bulky dye-lichens themselves has not yet been adopted by manufacturers, 

 though recommended strongly by chemists. 



10. New commercial sources of valuable tinctorial Roccellce have been discovered 

 — new markets opened up. Then- present chief geogi-aphical sources are, 



1. Africa and its islands. 



2. South America ; and 



3. India and its islands. 



11. The commercial som-ces of " orcheUa weeds " of the finest quality may yet be 

 greatly Inultiplied, and are so far from being exhausted, that they cannot yet 

 be said to be fully developed or discovered. 



12. The only visible effect of competition -w-ith other dye-stuffs has been greatly . 

 to reduce the market value of ''orchella- weeds." 



13. Nevertheless, tlieir products — French purple, orchill, and cudbear — are suc- 

 cessfully competing with the aniline, and all other colours, of their class 

 hitherto introduced. 



14. So far from being superseded, the import of dye-lichens and manufacture of 

 lichen-dyes in Europe is, perhaps, now more extensive and more flourishing 

 than at any previous period. 



15. The manufacture of lichen-dyes in this country has not reached perfection ; 

 and if with all their imperfections of manufactui'e they can successfully com- 

 pete with aniline, whose preparation and applications are much more highly 

 scientific, they have little reason to fear competition in the future, when 

 applied chemistry shall have lent its aid to their proper production and 

 applications. 



Under the head of 



II. Domestic Dye-lichens and Lichen-dyes, 



the author's chief propositions arc as follow : — • 



1. The domestic use of lichen-dyes is prevalent over whole districts in Scotland, 

 — even in and around large seaports, which have steam commimication with 

 Glasgow or Edinburgh, sometimes two or three times a week (e. rj. Stornoway), 

 and which may be presumed therefore to be well supplied with the cheapest 

 and most abundant products of British manufacture. 



2. In the outer Hebrides (Lewis and Harris) " Crottle * " {Parmelia saratilis) 

 is universally used in the dyeing of 



a. " Kelt," a home-made cloth. 



b. Stockings and socks. 



c. Polkas and scarfs. 



d. Hearthrugs and other articles. 



3. The articles of clothing so dyed are disposed of hi/ barter to the merchants 



* The term " Crottle " or " Crotal" is also applicable generically to dye -lichens. AVith 

 various descriptive prefixes, it has been, or is, applied in different p.irls of the United 

 Kingdom to otlier species of Parinelia, as well as to species of other genera, e.g., to 



ParmeUa saxatilis, var. omphalodes — black crottle. 

 P. pkysodes — dark crottle. 

 P. caperata = stone crottle. 

 Lecanora tartarea = (par excellence) crottle. 

 L. parcUa = light crottle. 

 Isidium corallinum = white crottle. 

 Sticta 2ndmonacea = hazel crottle. 

 Vide the author's work on ' British Lichens ' (1856), p. 336. 



