564
ELEMENTS OF MATERIA MEDICA.
Composition. —It has been analyzed by Herberger (Dierbacli, Dieneuesten Entd. in d. Mat. Med. 1837), and by Feuchtwanger (.AmericanJournal of Science and Arts, xxvi.)
Herberger.
Vegetable jelly .
Mucus.
Two resins .
Fatty matter and free acids .Chlorides of sodium and calcium,potash, lime, &c.
No traces of iodine or brominecould he recognized.
i Feuchtwanger.
79-1 i T .. J Pectin (a large portion).
0-7 I Oxalate of lime.
traces Compounds of sulphur, chlorine, andi bromine.
traces j No fuugic, boletic, or lichenic acids.
The mucilaginous matter (called by some writers vegetable jelly, by others pectin,)appears to me to be a peculiar substance, which I shall term carrageenin. It issoluble in boiling water, and its solution forms a precipitate with diacetate of lead andsilicate of potash, and, if sufficiently concentrated, gelatinizes on cooling. Carra-geeniu is distinguished from ordinary gum by its aqueous solution not producinga precipitate on the addition of alcohol; from starch, by its not assuming a blue colourwith tincture of iodine; from animal jelly, by tincture of nutgalls causing no preci-pitate ; from pectin, by acetate of lead not throwing down any thing; as well as by nomucic acid being formed bv the action of nitric acid. Dr. Lucae ( Berlin. Jahrb. xxxiv.Abth. i.) regards carrageenin as more closely resembling animal jelly than any othersubstance.
Chemical Characteristics. —The presence of carrageenin in thedecoction is demonstrated by the tests just enumerated. No iodine isrecognizable by nitric acid and starch. Oxalate of ammonia detects lime(or calcium) in solution, while nitrate of silver points out the presence ofchlorine. Guibourt ( Journ. de Chim. Med. viii. 663) could recognizeneither sugar nor magnesia.
Physiological Effects. —Chondrus crispus is nutritive, very diges-tible, emollient, and demulcent.
Uses. —It is a popular remedy for pulmonary complaints (especiallyof a phthisical character), chronic diarrhoea and dysentery, scrofula,rickets, enlarged mesenteric glands, irritation of bladder and kidneys, &e-As a culinary article it is employed as a substitute for animal jelly, inthe preparation of blanc-mange, jellies, white soup, &c.
Administration. —It is usually exhibited in the form of decoctionor jelly.
1. Decoctum Chondri. —Macerate half an ounce of carrageenincold water, during ten minutes; then boil in three pints of water, f°ja quarter of an hour. Strain through linen. Milk may be substitutedfor water when the decoction is required to be very nutritious, bydoubling the quantity of carrageen a mucilage is procured. Sugar?lemon juice, tincture of orange-peel, or aromatics, as cinnamon or nut-meg, may be employed as flavouring ingredients.
2. Gelatin a Chondri. —Prepared by concentrating the decoction?or by employing a larger quantity of carrageen.