The amphibia form a link between animal substances and fish. The turtle, the delight of the epicure, is an example of this class; but the species we shall afterwards mention at length. The conger eel, in its flesh, approaches also animal substances.

The rank which fish in general ought to bear in the scale of digestibility, has not yet been settled. Sea-fish bear, we suspect, the same relation to river-fish, that wild animals do to tame ones; and the fish of stagnant ponds are less digestible than those of running water. The meat of the same fish differs according to the period of spawning: fish are in perfection not at the moment of this' crisis, but when the melt or pea begins to enlarge. They differ also according to the time they have been killed, and from the operation of crimping. These subjects must be resumed when we speak of the different kinds of fish, as it would not be easy to give a general rule.

Of the insects but one species (the locust) has been eaten, except those of the sea. Of the locust we have no experience; but the white kind, not unlike crabs, is seemingly a mild nourishing food. In the east they are boiled or roasted, and, like crabs, become then of a red colour. They were eaten, as we are informed by Dio-dorus, by the AEthiopians: and Dampier tells us, that the custom still continues. Of the sea insects, crabs, lobsters. etc. appear to be mildly nutritious; in many constitutions more so than animal food.

Of the terrestrial vermes we take but one species, the snail, and this in England rather as a medicine than as food. The marine vermes, the oyster, etc. rank among foods easily digestible, and may be considered, when not roasted, as the most digestible of animal nutriment.

We cannot leave these more general doctrines respecting aliment without noticing some fancies respecting the nutritious powers of mineral substances. The pangolin has undoubtedly been dug out of a sand hill, where it seemingly could have no access to vegetable or animal nutrimem: yet we know not but that it might have laid in a stock of food, as some animals that have their returning periods of torpor require no nourishment for a long period: nor can we say that it finds no vermes in the sand. Some tribes of Indians have also, it is said, in periods of scarcity, devoured a species of steatite. That the greasy appearance of some steatites may have induced them to consider such mineral substances as nutritious, is not surprising; but that they have proved so is doubtful. Much of the pain of hunger arises from emptiness, and this may be in part avoided by any substance; and it is equally avoided by external pressure on the stomach, a practice not uncommon among savages, when food cannot be pro-curedas we have now stated the more general facts respecting aliment, we shall resume the consideration of the different classes, not only to point out the different species employed, but to remark some peculiarities which will influence our conclusions in the choice of different articles of food.

We began with the biros, as many of these afford lighter nutriment than the flesh of quadrupeds. We shall follow in some measure the classes and orders of the historian of nature, though we must invert their order. Birds, in a dietetic view, may be divided into the more or less digestible. The extremes are well marked, viz. the gallinae and the accipitres of Linnaeus. Experience has decided that chicken are the most easily assimilated of the feathered race; and though some doubts may perhaps be suggested, from a comparison of some of these with other species, yet, on the whole, as a general position it may be admitted. Of the .gaalinae, some species of every genus are occasionally eaten, and perhaps every one will afford a moderately mild food. Even the ostrich, when young, is a delicacy. The most common species, which adorn the tables, belong to the genus phasianus Lin. the domestic fowls; the meleagris, the turkeys; pavo, the pea-hen; otis, or the buzzards; and the tetrao, including the partridges, black cocks, etc. The quail belongs to this genus. These are all graminivorous. The rails, particularly the rallus grex, connects them with the grallae on one hand; the pigeons and larks with the passeres on the other. The grallae afford a more sapid food, and we suspect often a more digestible aliment. The rails we have already mentioned; but the edible species of scolopax (the woodcocks and snipes) are more commonly known and esteemed. The genus tringa, including the sand-pipers, and the knots, may be next arranged; and the chara-drius, the plover, is scarcely inferior. Some of the other genera are seldom eaten; and the herons and curlews, though not rejected, are not, on account of their fishy flavour, to be recommended when the digestion is weak.

The columbine race resembles, rather in appearance, than in qualities, the gallinae. The young pigeon is, however, easily digestible; but the older birds are dry and insoluble. We have had reason to believe, that none of the columbae, when they exceed half their usual size, are easy, of digestion; and, when full grown, they have often created uneasiness in the stomach. The alaudae Lin. are often eaten, and the flesh of the a. ar-vensis is safe to be of a delicious flavour in the southern climates; though accused, perhaps without reason, of being injurious in calculous complaints. The greater number of the passeres are too small to enable us to determine their relative digestibility, as they cannot wholly form a meal, even for an invalid. We have reason to think them in general easily digestible.

The anseres usually afford a gross indigestible food, unless in the earliest periods of their existence. The genus anas offers the greater number of the edible species. All species of the anas have been occasionally eaten; but the wild kinds are often lean, hard, and fishy; the tamer ones, which have been fed on grain, are sapid; and, when young, easily digested. The teal is the most delicate of the wild kind, and the young duck of the tame anseres. Of the auks, some of the younger kinds, when cured by smoke, are eaten by the inhabitants of the northern regions; and the egg of the arctic auk is said to be delicious. The penguins also have been eaten from necessity, and their eggs commended; but we find only among common foods the pelicanus bassanus, the solan goose from the Bass island. Some of the shags, also, which belong to this genus, have been occasionally employed as food. Of the gulls, one species is mentioned by Sauer, as delicious, and not unlike the turkey.