34

ELEMENTS OF MATERIA MED10A.

of uniform cellular tissue. Reproduktive maller either altogether wanting, or contained injoints of the filaments, or deposited in thcca of'various forms, size, and position, caused bydilatations of the substance of the frond. Sporules with no proper integument, in germina-tion elongaling in tvvo opposite directions (Lindley).PßOPERTiEs.—None of the plants of this order are poisonous. A mucilaginous 1 or gelatiniformmatter (carrageenin, pectin) and sugar {mannite) render several species nutritious, emol-lient, and demuleent. Some Algse have been found beneßeial in scrofulous affections andglandulär enlargements. The good effects are referrible to iodine, (sce vol. i. pp. 229, 223),and in part, perhaps, to alkaline salts. A verrnifuge property has been aseribed to somespecies.

Laennee (Treat. on Diseases oftJie Chest, by Dr. Forbes, p. 369) tried the influence of anartificial " marine atmosphere" (air impregnated with the vapour of fresh sea-weed) on con-sumptive patients, and was impressed with an idea of its efficacy ; but experienee shows thatthe inhabitants of sea-coasts are as liable to phthisis as those of inland districts.

1. FU'CUS VESICULO'SUS, Linn. D.—SEA WRACK.

Sex. Syst. Cryptogamia, Algffi.(Herba cum fructu. Ph. Dub.)

History. —Theophrastus (Hist. Plant, lib. iv. cap. vii.) mentions severalspecies of Algae (fpüxoj), but he includes under this name Rocella tinctoria.Fucus vesiculosus is sometimes termed Qiiercus marina, Bladder Fucus, andCommon Sea-ioare.

Botany. Gen. char.— Frond plane, compressed or cylindrical, linear, di-chotomous, coriaceous. Air-vessels [vesiculce] when present innate in the frond,simple, large. Rcceptacles terminal (except in F. nodosus), turgid, containingtubercles, imbeddod in mucus, and discharging their seeds [sporangia] byconspicuous pores (Greville).Sp. char.— Frond plane, linear, dichotomous, entire at the margin. Air-ves-sels roundish-oval in pairs. Receptaclesmostly elliptical, terminating the branches[Greville).

Hab—Sea-shores. Very common everywhere.

Physical Properties. —Its substanceis thickish, flexible, but very tough. Itscolour is dark, olivaceous, glossy green,paler at the extremities, becomes blackby drying. Its odour is strong ; its tastenauseous.

CoMPOSITION AND ChAEACTERISTICS.

—It has been analyzed by Stackhouse,[Dict. Seien. Nat. xvii. 500), by Gualtierde Claubry, [Ann. Chim. xciii. 116), byJohn, [Schweigger's Journ. xiii. 464,)and by Fagerstrom, (Gmelin, Handb. d.Chem. Bd. ii. S. 1354).

It is composed of Cellular Tissue,Mucilaginous Matter (pectin 7) OdorousOil, Colouring and Bitter Matters, andSalts of Calcium and Sodium (iodide,sulphates, and chloride).

By treating the distilled water of Fucusvesiculosus with ether, a semi-solid whiteoil is extracted, which is the odorousprinciple. The aqueous decoction of thisplant is neutral, and contains chloride of sodium, sulphates of soda and lime,

Fig. 106.

Fucus vesiculosus.

a. Upper part of a frond.

b. Section of a receptacle.

c. Tubercle.

d. Filaments and sporangia, of which the tuber-

cles are composed.

e. Filaments which issue from the pores on the

surface of the frond.

i On the Mucilage of the Fuci, with Remarks on its Application to economical ends, by Mr. S. Brown, Jr.in Jameson's Edinb. New Phil. Journ. vol. xxvi, p. 4Ü9,1833.