903 



in particular, every homestead had its reservoir of 'graith;'* and 

 the ' lit-pig,' t which stood by every fire-side, was as familiar an 

 article of furniture in the cots of the peasantry as the * cuttie-stool,' 

 or the ' meal-girnel.' So lately as 1841 (and 1 presume the practice 

 continues to the present day), Mr. Edmondston stated that, of four or 

 five native dyes used by the Shetlanders to colour cloth and yarns, 

 two, at least, were furnished by lichens, viz.^ a brown dye from Par- 

 melia saxatilis, under the name of ' scrottyie,' and a red one from 

 Lecanora tartarea, under that of ' korkalett.' It is very probable, 

 however, that steam and free trade have gradually dispelled this good 

 old custom, even in the remoter corners of our island ; machinery- 

 made articles being now readily supplied at a rate so extraordinarily 

 cheap, as to render it absolutely expensive (as to time, if not also as 

 to money) to prepare colours, even by a process so simple and inex- 

 pensive as that just mentioned." 



Under the 3rd head, the author examined, in a general way, the che- 

 mistry of the colorific and colouring matters of the lichens, and the re- 

 sults to which it has led, avoiding as much as possible the technicalities 

 inseparable from such a subject, and giving a short vise of the researches 

 of Heeren, Kane, Rochleder, Heldt, Stenhouse, Schunck, Laurent, Ger- 

 hardt, and others. " Our untaught senses should undoubtedly lead us to 

 expect the lichens, whose thallus exhibits the brightest tints, to yield 

 the finest dyes, and these, too, of a colour similar to that of the thal- 

 lus ; but experience teaches us that the beautiful reddish or purplish 

 colouring matters are producible, in the greatest abundance, by the 

 very species from which we should least expect to derive any, viz., in 

 those most devoid of external colour. This, though at first sight very 

 remarkable, is easily explicable, when we remember that, in most of 

 the so-called dye-lichens, colorific principles exist in a colourless 

 form, and only become converted into coloured substances under a 

 peculiar combination of circumstances. 



" Some lichens contain colouring matters ready formed ; and these 

 exhibit themselves in the tint of the thallus of the plants; e. g., chry- 

 sophanic (or parietinic) acid in Parmelia parietina, and vulpinic acid 

 in Evernia vulpina. In other species, we find principles which, while 

 in the plant, and unacted on by chemical reagents, are colourless ; 

 but which, when the lichens are exposed to the combined influence 



* The vernacular name for stale or putrid urine. 



t " Lit " was the name applied to the plant from which the dye was to be pre- 

 pared ; and " pig " is the Scotch synonym for any kind of earthenware vessel in which 

 the maceration was generally carried on. 



