Ray has long since informed us[130], from Bartholine, that in the spring time, while it is young, it will purge; in consequence of which it is used as common spring physic. This quality it loses in a short time; and what serves for physic in the spring, is converted the remaining part of the year into food. They collect large quantities of it, grind it into meal, and make both pottage and bread of it. It is in common use not only with the islanders, but in several parts of Sweden also, where it is found to be a very appropriate diet in phthisical cases[131]. These accounts of the excellent use of this lichen correspond perfectly well with the last accounts of it in Mr. Horrebow’s Natural History of Iceland, just published; and which I shall take the liberty of transcribing as follows: “There is another herb, called _muscus catharticus islandiæ_, or mountain-grass, which they cook up into a delicate dish. I have often eat of it; at first out of curiosity, but afterwards for its palateableness and wholesomeness. The excellent qualities of this herb are described in the Memoires of the Society of Arts and Sciences in Sweden. It grows in great abundance; and those that live near the places, where it is found, gather great quantities for their own use, and to send to market. People that live at a great distance will send and fetch horse-loads away. Many use no meal or flour at all, when they are stocked with this herb, which in every respect is good and wholesome food”[132]. This moss is not very common in the southern countries of Europe. England affords it but very sparingly. Mr. Newton and Dr. Dillenius found it in Wales; Sibbald, in Scotland. It is frequent on the Alps of Switzerland; and Dr. Haller mentions it in his _Iter Hercynium_. Sweden and Lapland have it in plenty: and on account of its great abundance and usefulness in Iceland, Bartholine, and after him others, called it _muscus islandicus_. CONCLUSION. I cannot help remarking, by way of conclusion, that we have in this genus of plants a convincing instance of the utility which may result from the study of natural science in general, and even of its minuter and hitherto most neglected branches. From a view of the foregoing memoir it is evident, I presume, that the œconomical uses of the lichens, in the various parts of the world, are already very considerable and important: and altho’ it does not appear, that the sensible qualities of any of them, or the experience of former ages, will warrant our ascertaining any singular powers to them in a medicinal way, yet posterity will doubtless find the means of employing them to many valuable purposes in human life to us unknown.