Marine Algae

The seaweeds on our coasts are comparatively nutritious food. In a moderately dry condition they are said to contain from 18 to 26 per cent, of water, 9 1/2 to 15 per cent, of nitrogenous constituents, and about 66 per cent, of starchy matter and sugar. They are consequently shown to be richer in nitrogen than oatmeal or Indian corn.

The edible socweeds are, Ulva latiforina, Porphyra laciniata, Condrus crispus, Laminaria digitata, Laminaria saccharina, and Alaria esculenta.

Ulva Latissima

Is a deep green weed, covering the stones as well as the rocks as the tide recedes, called by fishermen "oyster green," because employed to cover oysters. It is also called laver, as it is used by epicures instead of the true laver, when Porphyra cannot be procured, but it is by no means so good.

Porphyra

(From a Greek word signifying "Furple.")

Generic Character

Delicately membranaceous, fiat, purple.

Porphyra is also called Laver and Sloke. It is a favourite dish with some people, stewed for several hours until quite tender, and eaten with pepper, vinegar, and butter; others prefer it cooked with leeks and onions, or pickled and eaten with oil and lemon-juice. It does not look inviting and the taste is peculiar, but is very wholesome, and will keep a long time in closed tin vessels; it is therefore valuable in long sea voyages.

Chondrus

(Name signifying "Cartilage," from the toughness of its frond).

Generic Character

A flat, cartilaginous frond, divided into branching lesser fronds of purplish or livid red colour.

Fructification

1. Tubercles, or warts, composed of radiating threads, whose lower joints transfoim into spores. 2. Tetraspores collected into sori, immersed in the substance of the frond.

Chondrus Crispus

In deep pools between half-tide and low water we shall find abundance of this seaweed, better known as Irish moss, or Carrageen moss, sold once as high as 1s. 6d. per pound, whilst in repute with physicians as a light and easily-digested food for invalids. This plant varies exceedingly in size and colour: in shallow pools, small, pale, and stunted; whilst in the shadow of a great rock, or down at the bottom of a deep pool, it has purple red and reddish-green thick fronds in dense masses. Carrageen Moss has been recently prepared and sold for making a cheap and nourishing blancmange.

Laminaria Saccharina

A single, smooth, brown frond, clear olive and glossy, with a conical root of twisted fibres. It well deserves its name "Saccharine," from the abundance of sweet mannite or manna which is secreted in its cells. This was discovered by Dr. Stenhouse some years ago: he took a quantity of this seaweed and macerated it in a particular way called "digesting" in hot water, which formed it into a brownish sweetish mucilage. When evaporated, it left a considerable quantity of saline semi-crystalline substance. This was reduced to powder and treated with alcohol, by which a considerable portion of it was dissolved. This solution yielded, on cooling, large hard prisms of fine silky lustre, very beautiful, purely white as loaf sugar and almost as sweet. This is mannite.

* "Common Seaweeds." By Mrs. Lane Clarke.