Chondrus

Chondrus crispus. Irish moss.

Cetraria

Cetraria Islandica. Iceland moss.

Decoctum Cetrariae

Decoction of Iceland moss.

Composition

The principal constituent of chondrus is a mucilage, which, when dry, is horny, but swells up in water, forming a jelly. Cetraria contains about seventy per cent of a starch (lichen-starch), a decoction of which gelatinizes on cooling. In addition to this starch cetraria contains a bitter principle (cetrarin), and a peculiar acid (lich-eno-stearic acid).

These lichens are used only for the production of diets for the sick. They were formerly supposed to possess some peculiar virtues which rendered them serviceable to pulmonary invalids. As articles of food, they have a very low position as regards nutritive value. The decoction of cetraria may be used as a stomachic tonic, containing as it does a bitter principle; but it is only to be prescribed when the more efficient remedies are not well borne.

Chondrus may be made into jelly or blanc mange, in the same way as gelatin is now prepared for this purpose. Neligan gives the following recipe for the preparation of a jelly from chondrus: Chondrus, washed and macerated, thirty grains; spring-water, a pint; boil down to one half and strain with expression, and add to the strained liquor four ounces of white sugar, one ounce of gum-acacia, and thirty grains of powdered orris-root; heat to dryness with a gentle temperature, stirring constantly so as to obtain a pulverulent mass, to which three ounces of arrow-root are to be added by trituration. A jelly is prepared with this powder by rubbing up a tea-spoonful of it with a little cold water, and then pouring a cupful of boiling water on it.