had its reservoir of “Graith,"[53] and the “Lit-pig,"[54] which stood by every fireside, 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 I presume the practice continues to the present day), Mr. Edmonston stated that, of four or five native dyes, used by the Shetlanders to color cloth and yarns, two at least were furnished by lichens, viz., a brown dye from Parmelia 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 colors, even by a process so simple and inexpensive as that just mentioned.”

Under the third head, he examined, in a general way, the chemistry of the colorific and coloring matters of the lichens and the results 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, and Heldt, Stenhouse, Schunck, Laurent, and Gerhardt, 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 color similar to that of the thallus, but experience teaches us that the beautiful reddish or purplish coloring-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 color.  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 colorless form, and only become converted into colored substances under a peculiar combination of circumstances.

“Some lichens contain coloring matters, ready formed, and these exhibit themselves in the tint of the thallus of the plants, e.g. chrysophanic [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 re-agents, are colorless, but which, when the lichens are exposed to the combined influence of atmospheric air, water, and ammonia, yield colored substances.  This series of colored products is usually comprehended more for convenience sake than on account of chemical identity, under the generic term orceine.”

The whole subject of the chemistry of these bodies is at present in a most unsatisfactory condition, demanding fresh investigation and research, in illustration of which, the author exhibited tables