Fucus. N. F. IV. Bladderwrack. Sea-wrack. Kelp-ware. Black-tang. Cutweed. Quercus Marina. Fucus [Varech) vesiculeux, Fr. Blasentang, Seetang, Meeriche, G. (Fam. Fucaceae.)—Fucus was retained in the National Formulary IV as "the dried thallus of Fucus vesiculosus Linne (Fam. Fucaceae)." This is a common seaweed growing on the rocks in the North Atlantic Ocean. "Sometimes a meter in length, but usually in shorter pieces, from 1 to 4 cm. in width, dichotomously branched, brownish black, usually with a slight, whitish incrustation; fiat, smooth, entire-margined, having a stout midrib throughout, along which are irregularly disposed pairs of air-vesicles which vary in diameter from 5 to 15 mm.; receptacles terminal, compressed, mostly ovate or elliptical and about 1 cm. in length, but varying from spherical and 5 mm. in diameter to linear-lanceolate and 5 cm. in length, forked, solitary, or in pairs. Odor strongly seaweed-like; taste saline and nauseous. Fucus yields not more than 20 per cent. of ash." N. F. The plant grows upon the shores of Europe and of this continent, attaching itself to the rocks by its expanded woody root. On the coasts of Scotland and France it is much used in the preparations of kelp. It is also employed as a manure, and is mixed with the fodder of cattle. It contains from 22 to 62 per cent. of mucilage and a peculiar cellulose, and about 0.1 per cent. of a volatile oil; the ash containing both iodine and bromine. Tollens and Kovoir state that 0.8 per cent. of a sugar named fucose, C6H12O6, exists in dried seaweed. Votocek and Potmesil obtained from fucose an alcohol which they named fucitol. (B. P. G., 1913, 3653.) Convoy has found in it 0.21 per cent. of iodine. (P. J., x, 434.) These ingredients remain in its ashes, and in the charcoal resulting from its exposure to heat in close vessels. On the coast of France about a dozen species of seaweed have been used in making kelp. According to Eugene Marchand, Fucus vesiculosus is one of those poorest in iodine, the different species of Laminaria containing far larger amounts of iodine than this Fucaceae. (See P. J., 1884, 1011.) Laminaria digitata (L.) Lamx. and L. stenophylla contain ten times as much iodine as the Fuci, and are practically now the only kelps used in making iodine. (See P. J., 1884, 1026.)
The charcoal derived from kelp was at one time used, under the name of Aethiops vegetabilis or vegetable ethiops, in the treatment of goitre and scrofulous swellings. The mucus contained in the vesicles was applied externally, with advantage, by Russell, as a resolvent in scrofulous tumors. Duchesne Duparc has obtained from it very good results in the treatment of morbid obesity. (J. P. C., 1862, 65.) A. T. Carson affirms, however, that the Fucus vesiculosus is largely used in Ireland for fattening pigs, and it is doubtful whether its preparations are capable of reducing human obesity unless given in such doses as to interfere with digestion and injure the health. A possible explanation of the action of bladderwrack in obesity, if it exercise any, is found in the experiments of Hunt and Seidell (J. P. Ex. T., 1910, ii, p. 15), who present evidence to show that the extract of this plant is a powerful stimulant to the thyroid gland. Dannecy prepares the extract from the plant, collected at the period of fructification and rapidly dried in the sun. The coarse powder he treats for three days, with four times its weight of alcohol of 86°, expresses at the end of this time, and subjects the residue twice successively to a similar treatment with alcohol of 54°. The tinctures are then mixed, the alcohol distilled off, and the remainder evaporated to the consistence of an extract. Of this extract, which is one-fifteenth of the plant, three pills, each containing 0.25 Gm. (3.75 grains), may be taken daily in the beginning, and increased gradually to twenty-four pills. (J. P. C., 1862, 434.) From the tincture a syrup may be prepared. Fluidextractum Fuci, N. F. IV is made with a menstrum of three volumes of alcohol and one volume of water from fucus in No. 30 powder.
Other species of Fucus are in all probability possessed of similar properties. Many of them contain a gelatinous matter and a sweet principle analogous to mannite, and some are used as food in times of scarcity. The varieties are classified by Fristedt as follows:
The Ceylon moss is a delicate fucus (Fucus amylaceus. growing on the coast of Ceylon. It abounds in starch and vegetable jelly, and is used like carrageen or Irish moss. (P. J., xiii, 355.) Sphaerococcus Helminthochorton (L.) Ag. (Fucus Helminthochorton L., Gigartina Helminthochorton Grev.) has some reputation in Europe as an anthelmintic and febrifuge. It is an ingredient in the mixture of marine plants sold in Europe under the name of Corsican moss or helminthochorton. This is used in decoction, from four to six drachms to the pint; dose, a wine-glassful three times a day. Large quantities of a seaweed, agar-agar, are gathered on the rocky coasts of the East India islands, and sent to China, where it is valued for making jellies and as a size for stiffening silks. (See Agar.)
Attention has been called by Sloan of Ayr, Scotland, to Laminaria digitata (L.) Lamx., (L. Cloustoni Edmonst.., commonly called sea-girdles or tangles, of Scotland, as supplying an admirable material for bougies. The stem is from two to twelve feet long and an inch or more in breadth, is of great strength and tenacity, with the property of drying readily, and, in doing so, of shrinking much, and acquiring an elastic firmness, with a consistence, if the desiccation be arrested at the proper point, somewhat softer than horn. In this state the plant may be kept for years, and is capable of absorbing moisture at any time and swelling to the original size, so that it has been used for the making of dilating bougies and tents.
The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.