In treating of the oceanic fields of sea-weed, some of the uses of Fucus natans (including F. natans, bacciferus, and several others of Turner) have already been hinted at. The most succulent fronds are selected, and prepared as a pickle, like samphire, and the young and tender shoots are eaten as a salad, seasoned with juice of lemons, pep per, and ginger. This sort of sea-weed is also in some repute as a medicine, being accounted aperient and anti scorbutic, and employed by the native Americans to cure fevers.
Many of the Asiatic nations bordering on the sea, use different species as food. The superior orders employ them chiefly to give consistence to sauces, or to moderate the pungency of the hot spices which they use in such profu sion.
In the East Indies, and particularly in Ceylon, F. liche noides (Turn. t. 118.) is in high estimation for the table. The following is its character : cc Frond sub gelatinous, filiform, much and irregularly branched; branches patent, nearly of equal height, acuminated, generally forked at their apices, with short divaricated segments ; tubercles hemispherical, sessile, scattered all over the frond." From the circumstance of its being used as an article of food, Gmclin, in his History of Fuel, gave it the title of F. cdulis, a name now appropriated to a very different one, allied to the palnzatus, and above described. F. lichenoides is com pletely of a gelatinous nature : it is washed in fresh water, and squeezed, so as to remove a considerable part of its mucilage and saltness; after which it is served up with a sauce prepared with lemon-jnice and ginger. This is sup posed to be one of the principal ingredients employed by the East Indian swallows in constructing those edible nests which are so much in repute, not only in China,but through out India, and in request even at the luxurious tables of London. The most pure and transparent nests are now generally believed to be almost entirely composed of the gelatinous fuci.
F. tenax is employed in the Chinese empire to serve all the purposes of our gum Arabic and glue, It is a small cy lindrical filiform species, allied to F. acicularis. It was first described by Turner in ?innals of Botany, vol. ii. and is figured in the History of Fuci, t. 125. It is gathered on the shores of the provinces of Fo•kien and Tche-kiang ; and although of small size, it is found so plentifully, that about 27,0001bs. are annually imported at Canton, and sold at 6d.
or 8d. per lb. As soon as gathered, it is dried in the sun ; and being then compressed, it will keep good for several years. When it is to be used, the saline particles and im purities are washed off; it is then steeped in warm water, in which it dissolves, stiffening as it cools into a vegetable gluten, which again liquifies on exposure to heat. It seems probable that this is the principal ingredient in the cele brated gummy matter called chin-chou, or hai-tsai, in China and Japan. Large sheets of paper or of coarse gauze are besmeared with it ; they thus acquire additional transparen cy, and are used in windows or lanterns. Windows made merely of slips of bamboo crossed diagonally, have fre quently their lozenge•shaped interstices wholly filled with the transparent gluten of the hai-tsai.
It is remarked by Mr Turner, (Hist. Foe. t. 216-218), that the common and well-known though very variable spe cies, F. crispus and mamillosus of our own shores, are rea dily melted by boiling, and that they afterwards form a ge latine. This has not yet, however, been applied to any use, either by the cook or the artist. Unfortunately they are not only of small size, but could not easily be gathered in sufficient quantity. • It may be mentioned, on the authority of Mr Barlow, that at the Cape a kind of gelatinous focus, very useful as food, is gathered, particularly from the shores of Ruben Islaud. The leaves are described as sword-shaped, serra ted, and about six inches long. These being first washed clean, and sufficiently dried to resist putrefaction, are steep ed in fresh water for about a week, changing it every clay. After this, being boiled for a few hours in a little water, they Form a clear transparent jelly ; which being mixed with su gar, and the juice of a lemon or orange, affords a pleasant and refreshing dish.
According to Dr °lairs Swartz, F. SPNOSILS, (muricatus of Gmelin) is eaten by the inhabitants of Sumatra. This species occurs at the Cape, but is there neglected.
Some of the gigantic species, particularly F.potatorum of Labillardicre, furnish various instruments and household vessels, as well as food, to the native inhabitants of New Rolland.