isinglass, for making moulds used by the plaster of Paris workers, for hardening the same material-in short, as a substitute for all kinds of gelatines, over which it has the advantage of producing a firmer jelly.

Another seaweed, much used for industrial purposes, is the fu, resembling the carrageen moss, and applied to similar uses, such, for instance, as the sizing of the warp of silk goods.

Seaweed is not much used for food purposes in Europe. In Ireland, dulse (Rhodomenia palmata) is either eaten with butter and fish, or boiled in milk with rye flour. The Ulva latissima, or green laver, and the Porphyra vulgaris, or purple laver, are abundant on the British shores, and when boiled and served with pepper, butter, and vinegar, form an agreeable delicacy to many persons when eaten with cold meat. The London shops are supplied with it from the Devonshire coast. In Ireland it is known as "sloke." "Tangle," which is the young fronds of Laminaria digitata, is much eaten in Scotland; and at one time the cry of "dulse and tangle" was as common in the streets of Edinburgh and Glasgow as that of watercresses is in London at the present day.

Miscellaneous Uses of Seaweed.-Various attempts have been made from time to time to manufacture paper from seaweed, but they have not been attended with any very great success.

In 1820 a patent was granted in Denmark for making paper from seaweed, which was alleged to be whiter, stronger, and cheaper than other kinds. In 1828 a patent was taken out in the United States, by Elisha Collier, for making paper from Ulva marina. In 1833 a patent was granted in France to Monsieur Tripot for making paper from seaweed. In 1875 two English patents were pro

visionally registered for making paper from seaweed, but these were never proceeded with.

Monsieur J. E. Brizot, of Toulon, states that to prepare paper from seaweed, it is necessary to pound the root part of the algae, to break off a kind of fibrous outer coating which does not bleach effectually. It is then washed to remove the sand and earth which are often found adhering, and beaten well, after which it is placed in a reservoir of water mixed with sulphuric acid. Seaweed is naturally tough and stiff, owing to the number of cellules which it contains; to render it supple for paper-making, it must therefore be steeped in an acid bath. In taking out the stuff from the reservoir, it should be removed with a wooden spade, pierced with holes, so that the acid water may be preserved for use again. The paper pulp may be placed in osier baskets to drain off the moisture. The filaments of the leaves should not be employed for white paper, as they do not bleach well. After cleansing and treating with the acid as already described, it only remains to bleach the material with chloride of lime till it is of the whiteness required.

Chevalier Claussen, when treating common seaweeds. with alkalies, found they were entirely dissolved and a soapy compound formed, which could be employed in the manufacture of soap.

A patent was taken out some years ago by Mr. T. Ghislin for utilizing dissolved and pressed seaweed, under the name of laminite, in making imitation horn, moulded for the handles of cutlery, for sticks, picture-frames, book-covers, etc. It was not followed up to any extent.

The New Zealanders employ the large pods of a species of seaweed to store the whale oil which they use in the lamps of their sleeping houses. These, when filled,

hold about a quart each, are tied up at the neck with flax fibre, and resemble in appearance a bottle of caoutchouc.

The large dried hollow fronds of a gigantic fucus serve as water buckets on the Pacific coasts of South America. Water pitchers used to be made by the aborigines of Tasmania of the broad-leaved kelp. They were often large enough to hold a quart or two of water. These and the shell of a species of Cymba were the only vessels they had for carrying water.

CHAPTER XIII.

MARINE SALT.

Mode of obtaining sea salt-Salines of France, where situated-Statistics of production-Composition of the crude salt-Manufacture in the United States-Consumption of salt in various countries-Sea-salt works of Portugal-Salt manufacture in India a Government monopoly—Imports of foreign salt-Salt production in Cochin China.

ANOTHER Commercial product from the sea is salt, obtained by evaporation, which is produced on a large scale in many quarters, especially in India, on the coast of France, in Turks Islands, and other localities. To obtain this salt a certain quantity of sea water is collected in reservoirs, constructed on the seacoast, which are termed salines, or salt marshes, where it is evaporated by the combined action of the rays of the sun and currents of air. As sea water contains only from two and a half to three per cent. of salt, a very large quantity of water has to be submitted to evaporation to obtain the salt of commerce. Notwithstanding this, the operations are carried on upon so large a scale, and the work is so arranged, that the salt is produced at a very moderate price.

France has about 82 salines, or salt marshes, occupying a surface of about 48,500 acres. These are situated, one

on the Channel coast, 36 on the shores of the ocean, and 45 on the coasts of the Mediterranean. These consist of one or more reservoirs, into which the sea water is passed. Those of the south are greatly superior to the others, because they are better managed, and the climate is more favourable for evaporation.

The sea water is introduced, either by means of a canal of the level of the sea banks, or by means of hydraulic machines in other cases, into a reservoir, which is shallow and of great extent of surface, so that the liquid may be subjected to the action of the sun's rays. In this reservoir, when the evaporation commences, the water passes off slowly into a series of rectangular basins, less deep, where it continues to concentrate, after which it passes into a trench which conducts it to the great wells, called the wells of green water. Pumps then raise it into a second trench, by which it is carried into another series of evaporating basins, called interior heaters, from which it passes into the reservoir, and from thence by a third trench into more wells, called the salt wells. Here the sea water marks 22° to 24° of Beaume's areometer. The pumps then pass it into a fourth trench, which carries it into new basins, smaller than the preceding ones, called salt tables. In these tables, where the liquid mass is not above five or six centimètres of depth, the salt is deposited. When the principal part of the water has left the product, the water is carried off by the canal to the sea, and a fresh quantity of condensed salt-water is brought into the salt-pans. The water is renewed daily or every two days, and this operation is carried on during all the fine weather, that is, from April to September. When the bed of salt is of the thickness of four or five centimètres, it is collected or shovelled up. For this purpose the masses of salt are left