The present practice has quite exploded it, and very justly perhaps, as in any degree specific in the above disorder. Nevertheless, it seems to have sustained that character with as great a reputation, and perhaps with as good a title to it, as almost any of the specifics of that age. It has been observed before, on another occasion, that this tribe of mosses have in general an astringent property; as such, the cup-mosses are consequently of a strengthening nature: it is no wonder, therefore, that they should be helpful in this disorder, merely as corroborants. That they were useful in some measure can scarcely be doubted; and our very eminent Dr. Huxham[96], in treating upon this obstinate complaint, seems to allow this of the cup-moss in preference to other idle specifics. Happily for us, the Peruvian bark supplies a remedy of infinitely more use, where such analeptics are required. Dr. Lister, in some ingenious observations of his, printed in the Philosophical Transactions[97], touching colours and dyes, observes, that the scarlet heads of these mosses, upon the affusion of lye, will strike a purple which will stand. 4. Lichenes crustacei. _Such as consist of a dry and friable matter, more or less thick, formed into flat crusts, very closely adhering to whatever they grow upon._ Some of the species of this division consist of an exceeding fine thin crustaceous, or rather, as Micheli calls it, farinaceous matter, the fructifications appearing in the form of tubercles. Others consist of a thicker scabrous crust, having the fructifications in the form of little cups, called _scutellæ_. This division contains the first order of the _lichenoides_ of Dillenius; the 5th, 6th, and 7th orders of Haller’s lichens; the _lichenes leprosi_ and _crustacei_ of Linnæus; and several of the _placodium_ of Hill. The species are numerous, and most of them very common on rocks, stones, old walls, the bark of trees, old pales, _&c._ which are commonly covered over with them, in undisturbed places. They form a very agreeable variety, and some of them have a very elegant appearance.