Chondrus crispus. Irish Moss.
Nat. Ord. — Algaceae. Sex. Syst. — Cryptogamia Algae.
Description. — Irish Moss, or Carrageen, as it is frequently called, has a root-disk throwing up tufts of many flat, nerveless, slender, cartilaginous fronds, from two to twelve inches in length, subcylindrical at the base, but immediately becoming flat, generally dilating from the base as they ascend, until they become three or four lines wide, and then dividing repeatedly and dichotomously, each division spreading and becoming narrower than the preceding one, and taking place at shorter and shorter intervals : the summits are bifid, the segments linear, wedge-shaped, varying greatly in length, rounded or acute, straight or curved, and often twisted in such a manner as to give the curled appearance denoted in the specific name. Fructification roundish or roundish-oval, subhemispherical. Capsules imbedded in the disk of the frond, prominent on one side, and producing a concavity on the other, containing a mass of minute, roundish, red seeds. Substance cartilaginous, in some varieties approaching to horny, flexible and tough. Color a deep purple-brown, often tinged with purplish-red, and paler at the summit, becoming greenish, and at length white in decay.
History. — This plant grows upon rocks and stones on the coasts of Europe, especially on the southern and western coasts of Ireland ; said also to be a native of the United States. When collected, it is washed and dried. It is of a yellowish-white color when dried, translucent, of a feeble odor, and nearly tasteless. Boiling water dissolves it, forming a jelly on cooling. Cold water does not dissolve it, but swells it up. It contains starch, a large proportion of pectin or vegetable jelly, which Pereira proposes to call Carrageenin, supposing it to be a distinct proximate principle, also compounds of sulphur, chlorine and bromine, and some oxalate of lime, etc. Carrageenin may be known from gum, by its watery solution not affording a precipitate with alcohol ; from starch, by not becoming blue with tincture of iodine ; and from pectin by giving no precipitate with acetate of lead, and no mucic acid by the action of nitric acid.
Properties and Uses. — Used in the form of decoction, with water or milk, as a nutriment, and as a demulcent in chronic pectoral affections, dysentery, diarrhea, and disorders of the kidneys and bladder. The decoction may be prepared by boiling half an ounce of the moss in a pint and a half of water, down to half a pint. Sugar and lemon-juice may be added to improve the flavor. It may be boiled in milk, when a more nutritious preparation is required.