gardens; and the bunches of vesicular grains which support these plants at the surface of the water, they name tropical grapes. Up to the present time these seaweeds have remained unutilized, doubtless because of the cost of transport.

Some of the species of seaweed are richer in ash than others. The most generally diffused species, the Fucus vesiculosus, or bladder-wrack, seems to withdraw the largest amount of saline and earthy matters from the sea water. Pereira, in analyzing the ash, found in it nearly 20 per cent. of common salt, and II to 12 per cent. each of potash, soda, and lime, and 24 per cent. of sulphuric acid.

Fresh weed usually yields 16 per cent. of ash, or 320 pounds to the ton of weed; and each ton of ash would yield 18 lbs. of phosphates, iron and lime, 38 lbs. of potash, and other mineral substances, making up a total of 164 lbs. of valuable saline matter, or more than one-half of the whole ash.

Valuable as are many of these ingredients to plants, the application of seaweed as a manure has some remarkable properties which do not appear to be explained by analysis.

The weeds are largely used in the west of Ireland, and a price paid for them far beyond their value as indicated by chemical composition. As a manure for potatoes they are hardly excelled. Along the coast of Cornwall they are successfully used for grass, cereals, and roots, and for apple orchards, spread round each tree. The broccoli, which is cultivated round Penzance in hundreds of acres, knows no other manure. From 10 to 20 tons per acre is the usual quantity applied. They act very rapidly, softening and decomposing in the soil so quickly that their effects are confined altogether to the special crop to which they are applied.

On the French coasts on the littoral of the Channel the collection of seaweed is carried on on an extensive scale. It was officially estimated some years ago at more than 2,000,000 cubic yards annually, or in weight about 2,250,000 tons. It is collected in various ways, with a drag, by the spade, by a rake with long handle, etc., and loaded into barges, carts, on donkeys, etc. So important is seaweed there considered as a fertilizer, that a work was published specially devoted to the subject.*

The collection of seaweed, by cutting from the roots, forms a considerable source of employment for the poorer classes on the coasts of Brittany. It is only permitted to be carried on from the period of full moon in March to the full moon of April. The collection of the driftweed thrown on the shores is, however, prosecuted all the year round.

In the Channel Islands the harvesting of the cut weed is carried on at fixed times-at Guernsey from July 17th to August 31st, and at Jersey for 10 days from March 10th and June 20th. About 30,000 loads are collected annually at each of the islands.

Études sur les Engrais de Mer," par J. Isidore Pierre. Paris: A. Goin.

Marine plants afford a large revenue for the manufacture of kelp and iodine. Kelp is prepared by burning the dead weeds till they are reduced to hard, dark-coloured cakes, in which state it is sent to market. Kelp is the only commercial source for the production of iodine, and its immense value in photography and in medicine has given an impulse to the manufacture of kelp, which renders it by far the most important of all the applications of seaweed. The average yield of iodine in Scotland from a ton of driftweed kelp is about five pounds.

The proportion of iodine in sea water appears to be very small, and it would require more than 30,000,000 pounds of sea water to furnish the marine alge with one pound of iodine.

The production of kelp in the United Kingdom amounts to about 10,000 or 11,000 tons; the manufacture is carried on in Ireland, the Western Islands, and Orkney and Shetland. In France there are many large factories at Granville, Cherbourg, etc.

The manufacture of iodine is chiefly confined to Great Britain and France, for very little is produced in any other countries. It was attempted on the American coasts of the Atlantic, but the weed was found to be of too poor a quality. The average production of iodine is about 10 lbs. to the ton of kelp, and as it requires 20 tons of wet weed to produce one ton of kelp, the total quantity made represents the burning of 400,000 tons of seaweed annually. At the present price the iodine produced is of more value than the alkaline salts, which were the original object of the industry.

Carrageen Moss.-One of the best known of the algæ in commerce is the Chondrus crispus, the source of carrageen or Irish moss, which is sometimes employed as a substi

tute for size and in brewing. It possesses nutritive, emollient, and demulcent properties, and may be employed in the form of a decoction or jelly in pulmonary complaints and other cases. Bandoline or fixature, for stiffening the hair and other purposes, is commonly prepared from carrageen. The market supply for England is obtained. from Clare and the west coast of Ireland. It used to be sent to the United States, where it is kept on sale by

1. Ulva latissima (green sloke). 2. Chondrus crispus (carrageen moss). most druggists. But it was soon found growing in immeasurable abundance along the whole Atlantic coast, from Nova Scotia to Long Island.

Comparatively few are aware of its wide and varied use in the arts, or of the thousands of barrels of it employed annually by manufacturers of paper, cloth, felt and straw hats, etc., and by brewers. Carrageen is to be found more or less abundantly all along the North Atlantic

coast, ranging between low-water line and the depth of 40 feet or so; but as a rule its fronds, which correspond to the leaves of air plants, are so numerously inhabited by small mollusca that they are spoiled for other use. The clean-growing article seems to be limited almost wholly to certain ledges in the neighbourhood of Scituate, Massachusetts. Here, where the waves of the Atlantic dash with full force upon the rocky coast, the carrageen grows to perfection; and, wherever it escapes the spawn of mussels and other shell-fish, is gathered during the summer season in vast quantities. The harvest begins in May and ends about the Ist of September.

The gathering is made in two ways-by hand-picking during exceptionally low tides, and by means of longhandled iron-toothed rakes at ordinary tides. Of course the work cannot be carried on except in fair weather. Hand-pulling is possible only during the bi-monthly periods of spring tides, that is, when the moon is full and again at new moon. At such times high tides occur about midday and midnight, and the ledges are exposed for moss gathering morning and evening. The mossers' boats are rowed to the rocks where the finest grades abound, and the gatherers select with care the growths that are freest from minute shells and other foreign matter. This portion of the crop, if properly handled afterwards, generally goes to the apothecary, and fetches a price two or three times that of the common grade. As the tide rises the pickers are driven to their boats, and proceed to the outer mossbearing rocks, where the rake is used, as it also is during ordinary low tides. Moss taken in this way is not so clean as the hand-picked, and is always mixed with tape grass, which must be removed during the process of curing and packing.