Dr. Hayes, in the course of his “Arctic Boat Journey,” was compelled to have recourse to the same unsatisfactory fare. The rock-lichen, or stone-moss, as he calls it, he describes as about an inch in diameter at its maximum growth, and of the thickness of a wafer. It is black externally, but when broken the interior appears white. When boiled it makes a glutinous fluid, which is slightly nutritious. “Although in some places it grows very abundantly,” writes Dr. Hayes, “yet in one locality it, like the game, was scarce. Most of the rocks had none upon them; and there were very few from which we could collect as much as a quart. The difficulty of gathering it was much augmented by its crispness, and the firmness of its attachment. “For this plant, poor though it was, we were compelled to dig. The rocks in every case were to be cleared from snow, and often our pains went unrewarded. The first time this food was tried it seemed to answer well,--it at least filled the stomach, and thus kept off the horrid sensation of hunger until we got to sleep; but it was found to produce afterwards a painful diarrhœa. Besides this unpleasant effect, fragments of gravel, which were mixed with the moss, tried our teeth. We picked the plants from the rock with our knives, or a piece of hoop-iron; and we could not avoid breaking off some particles of the stone.” These lichens are black and leather-like, studded with small black points like “coiled wire buttons,” and attached either by an umbilical root or by short and tenacious fibres to the rocks. Some of them may be compared to a piece of shagreen, while others resemble a fragment of burned skin. They are met with in cold bleak localities, on Alpine heights of granite or micaceous schist, in almost all parts of the world,--on the Scottish mountains, on the Andes, on the Himalayas; but it is in the Polar World that they most abound, spreading over the surface of every rock a sombre Plutonian vegetation, that seems to have been scathed by fire and flame, until all its beauty and richness were shrivelled up. * * * * * Some of the lichens in the less remote latitudes--as, for instance, in Sweden--are far superior in usefulness to any of those we have hitherto described. The Swedish peasant finds in them his pharmacy, his dyeing materials, his food. With the various lichens that grow upon the trees and rocks, says Frederika Bremer, he cures the virulent diseases which sometimes afflict him, dyes the articles of clothing which he wears, and poisons the noxious and dangerous animals which annoy him. The juniper and cranberry give him their berries, which he brews into drink; he makes a conserve of them, and mixes their juices with his dry salt-meat, and is healthful and cheerful with these and with his labour, of which he makes a pleasure.