ALISMACE^. 



73 



first by many of the inhabitants of these islands, it 

 soon became a profitable article of export, and has 

 contributed not a little to enrich the proprietors. It 

 has also long been manufactured in great quantities 

 in the western islands of Scotland, and a large part 

 of the population of these islands have been chiefly 

 supported by this means. Lately, Spanish barilla, 

 which is an alkaline substance, proceeds from the 

 ashes of the Salsola Kali and other maritime plants, 

 has been found superior to kelp in the formation of 

 glass and soap, and from the removal of the duty on 

 salt or muriate of soda, the impure alkali can be pro- 

 cured at such a cheap rate by chemical means, that 

 the demand for kelp is much diminished. In con- 

 sequence of this, many poor people have been de- 

 prived of their usual employment, and have been 

 compelled to have recourse to other means of sub- 

 sistence. The value too of many of the estates in 

 the Hebrides has fallen much on this account. 



Many of the sea-weeds are used as articles of diet. 

 The Rhodumcnia palmata furnishes the dulse of the 

 Scotch, the dillesk of the Irish, and the saccharina 

 sea-weed of Iceland. Pepper-dulse and tangle, sold 

 as articles of food in some parts of Scotland, are also 

 kinds of sea-weeds. From the various species of 

 Porphyra and Ulva a substance is procured, which, 

 when pickled or stewed, is brought to table under the 

 name of Laver. The edible nests constructed in 

 Asia by a species of swallow, the Hirundo csculenta, 

 are composed of several species of Gelidiciun, a sea- 

 weed common in the maritime parts of that country. 

 The Alaria csculenta, called in Scotland badderlocks, 

 or honey-ware, is also eaten. The Fucus vesicu- 

 hsus, sea-ware or sea-wrack of the English, kelp 

 ware or black tangle of the Scotch, serves for winter 

 food to cattle in several districts of Scotland. The 

 cattle are said to devour it greedily, and to repair 

 regularly to the shores at certain seasons of the year 

 for the purpose of procuring this and other species of 

 sea-weed. The Chondrus crispus, a sea-weed known 

 under the name of carageen or Irish-moss, has been 

 employed in Ireland and other parts of this country 

 as an article of diet. It forms a kind of blanc-mange, 

 which is very palatable and nutritive. A year or two 

 ago it was used for a short time in an institution in 

 Edinburgh as a light article of diet for invalids. 



In a medicinal point of view, sea-weeds are by no 

 means destitute of importance. Gigartina helmin- 

 thocaton, or Corsican moss, a sea-weed found in 

 the Mediterranean, was formerly much used as a 

 vermifuge. The Fucus vesiculosus was introduced 

 formerly into the British Pharmacopoeias, and was 

 used with success to discuss scrofulous swellings. 

 By burning it in close vessels a kind of charcoal was 

 procured, called vegetable sethiops, which was also 

 exhibited medicinally. Not many years ago it was 

 discovered that this and the other species of sea- 

 weeds contained a peculiar substance, which has re- 

 ceived the name of iodine. It was found that nearly 

 all the medicinal properties ofthe sea- weeds were owing 

 to the presence of this substance, which is now exten- 

 sively prepared from sea-water, and used in place of 

 the sea-weeds themselves, in cases of goitre and scro- 

 fulous tumours. It is a ) curious fact, that several 

 species of Laminaria have been long eaten by the 

 inhabitants of South America as a cure for these 

 diseases ; and burnt sponge, which is now known 

 to contain iodine, was formerly in use for similar 

 purposes. 



NAT. HIST. VOL. I. 



Sea-weeds are also employed for a great many 

 other purposes. The Granlluria tcnax is used as a 

 glue and varnish by the Chinese ; and the iMminaria, 

 bwcina/ix, on account of its j hollow stem, is used at 

 the Cape of Good Hope for making trumpets. 



The appearance of red snow, so often mentioned 

 by Arctic voyagers, is ascribed to a species of sea- 

 weed called Protococcus nivalis. 



Sea-weeds are extensively used as manure, and 

 for this purpose are gathered in various maritime 

 districts. The Highland Society have also lately 

 made experiments in regard to the value of kelp as 

 a manure, and their success has been such as to in- 

 duce extensive landholders to purchase considerable 

 quantities for agricultural purposes alone. Next to 

 the algae which yield the kelp above alluded to, the 

 saltwoods (salsola) on our shores are manufactured 

 for the same purposes. This is a genus of plants 

 which, after due preparation and calcination, produce 

 the alkaline salts called barilla, soda, potash, and 

 kelp. These plants, like maritime algre, require sea 

 air as well as water to bring them to perfection. Most 

 of them are herbaceous and annual, but some have 

 shrubby stems. Salsola kali is found on the sandy 

 shores of most parts of the world, and is generally 

 burned for soda for the glass manufacture. Salsola 

 soda is cultivated in Languedoc and also in Spain for 

 making barilla ; but is reckoned inferior to Salsola 

 sativa which grows on the Spanish shores of the 

 Mediterranean, and affords the best soda consumed 

 in Europe. It is called by us Spanish or Alicant 

 soda. In September the crop is cut and laid in small 

 heaps to dry. These heaps are then collected and 

 burned, forty or fifty of them in a hole in the ground. 

 Soda is in common use in the manufacture of glass 

 and soap ; with sulphur, it forms Epsom salts ; with 

 marine acid, common salt ; with the salt of Homberg, 

 borax ; and with cream of tartar, Rochelle salt. 



ALISMACE^E. The hundred and eightieth 

 order of the Jussieuan system, containing three ge- 

 nera ; viz. saglttaria, actinocarpus, and alisma, of which 

 there are twenty-six species. The flowers are white, 

 the divisions of the calyx and petals are distinct, 

 and have many seed-vessels. They form a beautiful 

 tribe of hardy aquatic perennial herbs, natives of 

 Europe and America. 



AI.ISMA PI.ANTAOO. n, flower .of the natural size ; b, fruit; 

 c, a single capsule ; d, the same in section to show the seed ; e, 

 seed (magnified;) /, the embryo (do.) 



Of the genus Sagittaria there are six known spe- 

 cies ; one of which, the common sagittifolia, is the 

 handsomest of our indigenous water plants. Several 

 of the other species are natives of China, Japan, and 

 North America. In China some of the species are 

 cultivated extensively, the root forming an important 

 article of food. The roots, however, are much larger 

 in those countries than they are with us ; of the 

 Actinocarpus, there are two species, one a native of 

 England, and the other of New South Wales, both 

 pretty floating aquatics 



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