Lond. Decoctum liche-nis Islandici, Edin. Decoction of Liverwort.

"Take of liverwort, five drachms; water, a pint and a half (two pounds, Edin.). Boil down to a pint, and strain."

Decoctum Lichenis Islandici, Dub. Decoction of Iceland liverwort.

"Take of Iceland liverwort, half an ounce; boiling water, a pint. Digest for two hours; then boil for a quarter of an hour, and strain the liquor while it is hot."

In these decoctions the bitter principle of the lichen is united with 44 per cent. of lichenin, a modification of fecula, with lichenates of potassa and lime, phosphate of lime, gum, sugar, and extractive. It is so nauseous that few patients will be persuaded to take it in this form. The dose is from f j. to f iv. three times a day. The addition of f 3ij. of distilled vinegar, and x. of tincture of opium, renders it very useful in phthisis.