And empty shells the sandy hillock grace. PRAWN SOUP.
198. INGREDIENTS.--2 quarts of fish stock or water, 2 pints of prawns, the crumbs of a French roll, anchovy sauce or mushroom ketchup to taste, 1 blade of mace, 1 pint of vinegar, a little lemon-juice.
Mode.--Pick out the tails of the prawns, put the bodies in a stewpan with 1 blade of mace, 1/2 pint of vinegar, and the same quantity of water; stew them for 1/4 hour, and strain off the liquor. Put the fish stock or water into a stewpan; add the strained liquor, pound the prawns with the crumb of a roll moistened with a little of the soup, rub them through a tammy, and mix them by degrees with the soup; add ketchup or anchovy sauce to taste, with a little lemon-juice. When it is well cooked, put in a few picked prawns; let them get thoroughly hot, and serve. If not thick enough, put in a little butter and flour.
Time.--hour. Average cost, 1s. 1d. per quart, if made with water.
Seasonable at any time. Sufficient for 8 persons.
Note.--This can be thickened with tomatoes, and vermicelli served in it, which makes it a very tasteful soup. [Illustration: THE PRAWN.]
THE PRAWN.--This little fish bears a striking resemblance to the shrimp, but is neither so common nor so small. It is to be found on most of the sandy shores of Europe. The Isle of Wight is famous for shrimps, where they are potted; but both the prawns and the shrimps vended in London, are too much salted for the excellence of their natural flavour to be preserved. They are extremely lively little animals, as seen in their native retreats.
[Illustration] FISH. CHAPTER VII.
THE NATURAL HISTORY OF FISHES.
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199. IN NATURAL HISTORY, FISHES form the fourth class in the system of Linnaeus, and are described as having long under-jaws, eggs without white, organs of sense, fins for supporters, bodies covered with concave scales, gills to supply the place of lungs for respiration, and water for the natural element of their existence. Had mankind no other knowledge of animals than of such as inhabit the land and breathe their own atmosphere, they would listen with incredulous wonder, if told that there were other kinds of beings which existed only in the waters, and which would die almost as soon as they were taken from them. However strongly these facts might be attested, they would hardly believe them, without the operation of their own senses, as they would recollect the effect produced on their own bodies when immersed in water, and the impossibility of their sustaining life in it for any lengthened period of time. Experience, however, has taught them, that the "great deep" is crowded with inhabitants of various sizes, and of vastly different constructions, with modes of life entirely distinct from those which belong to the animals of the land, and with peculiarities of design, equally wonderful with those of any other works which have come from the hand of the Creator. The history of these races, however, must remain for ever, more or less, in a state of darkness, since the depths in which they live, are beyond the power of human exploration, and since the illimitable expansion of their domain places them almost entirely out of the reach of human accessibility.
200. IN STUDYING THE CONFORMATION OF FISHES, we naturally conclude that they are, in every respect, well adapted to the element in which they have their existence. Their shape has a striking resemblance to the lower part of a ship; and there is no doubt that the form of the fish originally suggested the form of the ship. The body is in general slender, gradually diminishing towards each of its extremities, and flattened on each of its sides. This is precisely the form of the lower part of the hull of a ship; and it enables both the animal and the vessel, with comparative ease, to penetrate and divide the resisting medium for which they have been adapted. The velocity of a ship, however, in sailing before the wind, is by no means to be compared to that of a fish. It is well known that the largest fishes will, with the greatest ease, overtake a ship in full sail, play round it without effort, and shoot ahead of
it at pleasure. This arises from their great flexibility, which, to compete with mocks the labours of art, and enables them to migrate
thousands of miles in a season, without the slightest indications of languor or fatigue.
201. THE PRINCIPAL INSTRUMENTS EMPLOYED BY FISHES to accelerate their motion, are their air-bladder, fins, and tail. By means of the air-bladder they enlarge or diminish the specific gravity of their bodies. When they wish to sink, they compress the muscles of the abdomen, and eject the air contained in it; by which, their weight, compared with that of the water, is increased, and they consequently descend. On the other hand, when they wish to rise, they relax the compression of the abdominal muscles, when the air-bladder fills and distends, and the body immediately ascends to the surface. How simply, yet how wonderfully, has the Supreme Being adapted certain means to the attainment of certain ends! Those fishes which are destitute of the air-bladder are heavy in the water, and have no great "alacrity" in rising. The larger proportion of them remain at the bottom, unless they are so formed
as to be able to strike their native element downwards with sufficient force to enable them to ascend. When the air-bladder of a fish is burst, its power of ascending to the surface has for ever passed away. From a knowledge of this fact, the fishermen of cod are enabled to preserve them alive for a considerable time in their well-boats. The means they adopt to accomplish this, is to perforate the sound, or air-bladder, with a needle, which disengages the air, when the fishes immediately descend to the bottom of the well,
into which they are thrown. Without this operation, it would be impossible to keep the cod under water whilst they had life. In swimming, the fins enable fishes to preserve their upright position, especially those of the belly, which act like two feet. Without those, they would swim with their bellies upward, as it is in their backs that the centre of gravity lies. In ascending and descending, these are likewise of great assistance, as they contract and expand accordingly. The tail is an instrument of great muscular force, and largely assists the fish in all its motions. In some instances it acts like the rudder of a ship, and enables it to turn sideways; and when moved from side to side with a quick vibratory motion, fishes are made, in the same manner as the "screw" propeller makes a steamship, to dart forward with a celerity proportioned to the muscular force with which it is employed.
202. THE BODIES OF FISHES are mostly covered with a kind of horny scales; but some are almost entirely without them, or have them so minute as to be almost invisible; as is the case with the eel. The object of these is to preserve them from injury by the pressure of the water, or the sudden contact with pebbles, rocks, or sea-weeds. Others, again, are enveloped in a fatty, oleaginous substance, also intended as a defence against the friction of the water; and those in which the scales are small, are supplied with a larger quantity of slimy matter.
203. THE RESPIRATION OF FISHES is effected by means of those comb-like organs which are placed on each side of the neck, and which are called gills. It is curious to watch the process of breathing as it is performed by the finny tribes. It seems to be so continuous, that it might almost pass for an illustration of the vexed problem which conceals the secret of perpetual motion. In
performing it, they fill their mouths with water, which they drive backwards with a force so great as to open the large flap, to allow it to escape behind. In this operation all, or a great portion, of the air contained in the water, is left among the feather-like processes of the gills, and is carried into the body, there to perform its part in the animal economy. In proof of this, it has been ascertained that,
if the water in which fishes are put, is, by any means, denuded of its air, they immediately seek the surface, and begin to gasp for it. Hence, distilled water is to them what a vacuum made by an air-pump, is to most other animals. For this reason, when a fishpond, or
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other aqueous receptacle in which fishes are kept, is entirely frozen over, it is necessary to make holes in the ice, not so especially for
the purpose of feeding them, as for that of giving them air to breathe.
204. THE POSITIONS OF THE TEETH OF FISHES are well calculated to excite our amazement; for, in some cases, these are situated in the jaws, sometimes on the tongue or palate, and sometimes even in the throat. They