common plan pervades the whole; that the same general objects are had in view in the structure of all, and that there is a general analogy in the methods employed for effecting these objects, although there is a great variety in the details; that there is a grand simplicity in the design, though a great diversity in the means. In short, not only in the structure of each individual animal, but in the wonderful manner in which the structure is varied to correspond to the nature, habits, and wants of the different classes, we may perceive the power, the wisdom, and the goodness of that great Creator, who has devised and formed, and who continues to sustain, the myriads of animated beings with which the earth is filled.

THE PHILOSOPHY

OF

NATURAL HISTORY.

V

CHAPTER I. (W.)*

OF THE FOOD, DIGESTION, AND BLOOD OF ANIMALS.

A GENERAL view of the several functions that subserve the purposes of animal life has already been given in the Introduc tion; but there are many other circumstances relating to them which still remain to be considered.

The form of the face and head, the general structure and proportions of the body and limbs, the means of attack and defence, the strength, agility, and speed of an animal, all correspond to the organs of digestion, and bear a definite relation to them, and to the kind of food.

Man cannot seize his food with his mouth, for his lips and teeth are upon a plane with the general surface of his face; but he has hands by which he conveys it there. In other animals, just in proportion as the hands or fore feet become less adapted to this purpose, the mouth, face, and teeth become projecting, so as to make up for the deficiency. Thus the hands of the monkey are less perfect than ours, but his face is more protuberant. The Carnivora have jaws of more power, and hands again of less, whilst in the hoofed animals as the horse, and ox the jaws *In the subsequent parts of this work, the chapters which are taken chiefly from the original publication of Smellie are denoted by S., and in these the passages substituted or added in the present edition are distinguished by a single inverted comma. The chapters prepared chiefly by the Editor are denoted by W., and the passages retained from the original are distinguished in the same way.

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become very protuberant, and the fore feet are merely adapted for motion. This gradation in structure is also connected with the kind of food. Where an animal, as a hoofed quadruped, feeds upon substances firmly fixed to the earth, the mouth and teeth are sufficient. Where the food is not fixed, as flesh or fruit, something more is required. Hence animals living upon flesh, use their fore legs to hold down their prey while they tear it with their teeth; those living upon small fruits hold them between their fore feet, like the squirrel; whilst man and the monkeys, whose food is more various, have hands by which they can handle and prepare it.

Man is evidently capable of living, and does live, upon a great variety of food. But the question has been often discussed, whether his natural food be animal or vegetable? Is he, like most other animals, fitted by his nature to subsist upon a particular kind, or was he intended for that variety of diet, to which he has recourse? In his anatomical structure he is certainly most nearly allied to those species, such as the monkeys and their allied tribes, which in a state of nature live exclusively on fruits and vegetables. But experience shows that he is able to live, and enjoy at least equal health and strength, upon substances from the animal kingdom also. Some nations live exclusively on the one, some on the other; whilst the majority of mankind are addicted to the indiscriminate use of both. The tribes of Esquimaux, who inhabit the northern extremities of the earth, subsist entirely upon the flesh of whales, seals, walruses, bears, and fishes, never, except by accident, having the opportunity of tasting vegetable food. The Indians and Spaniards inhabiting some of the extensive plains of South America, frequented by immense droves of cattle, live almost exclusively upon beef. The Arabian supports himself on dried horseflesh, dates, and the milk and flesh of the camel; the millions of some of the regions of the East consume little else than rice; and the inhabitants of many portions of the tropical regions of the earth, subsist chiefly upon fruits and vegetables. Among the civilized nations of Europe and America, the tables of the better classes are spread with an immense variety from both kingdoms of Nature, whilst many of the poorer are limited to bread and vegetables.

Under all these different circumstances of diet, the average amount of health and strength does not seem, to common observation, to differ materially, so far as it is dependent on the kind of the food. Other circumstances appear to have more influence; such as the general mode of life, the occupation, the clothing, the habitations, and the quality and supply of air. It is probably true that if man have a sufficient quantity of aliment, and if his habits of life are well ordered in other respects, he may enjoy health, strength, and long life, upon all the kinds of food which have been mentioned. It is also true, however, that those tribes or classes of men whose situation enables them to gratify the appetite by a considerable variety, are more likely to attain to a high state of physical development, than those that are rigidly confined to a few articles.

The application of heat in the preparation of food undoubtedly contributes to the capacity for enduring this variety. Heat changes its texture and qualities; skilfully applied, it reduces very heterogeneous substances to a near approximation in their digestibility. Domestic animals whose food is cooked, resemble man in this respect. The dog and cat will subsist very well, and even exclusively, upon vegetable food, whilst, to some extent, though far less, some vegetable-eating animals will take animal food.

In fact there is not so great a difference between the products of the two kingdoms of Nature, used as food, as their sensible qualities would lead us to suppose. They consist essentially of the same principles. The vegetable world is the great laboratory in which food is prepared for the animal; and after its products have entered the bodies of animals, they are not greatly changed in their composition and essential qualities as articles for nutrition, though they are much altered from the texture and form in which they were swallowed.

The question then of the natural food of man is hardly capable of solution. It is as difficult to determine as that which relates to a supposed state of nature in other respects. Probably there is, in the proper sense of the word, no absolute or uniform state of nature. Calculated for an extensive distribution over the surface of the earth, man has been endowed with a power of accommodating himself to great differences in country, climate,

and food. He was probably not intended for any one residence more than another. He was intended for just what his instincts and propensities lead him to. As much for a hot climate as a temperate one, and as much for a cold one as either.

But though thus capable of living upon this variety of food, there is an almost necessary connection between certain conditions of life and its kind and quantity. In cold climates, not only a larger quantity is required, and of animal origin, but also that containing a great proportion of fatty matter. This is supposed to be rendered necessary in order to maintain the animal heat by its consumption. In hot climates, on the contrary, where this is hardly at all required, the quantity of food may be less, and especially of that containing fat. So, too, great bodily labor is supposed to be best maintained on a large proportion of animal food, but a sedentary and indolent life to require chiefly that of vegetable origin. There is probably a general truth in these opinions, but the deviations are so many as to render them liable to much modification.

Thus in the interior of Africa, in a hot climate, we are informed by travellers that the capacity for taking and digesting food is great. Dr. Oudney says of the Tuaricks, “We were told of two men who consumed three sheep at a meal; another who eat a kail of bruised dates, with a corresponding quantity of milk; another who eat about a hundred loaves of the size of an English penny loaf."

Still there is no reasonable doubt that in cold climates the demand for fatty animal food is more uniform, and the capacity of subsisting without it is less, than in warm. Indeed the instinctive avidity for it is sometimes almost startling. Captain Cochrane relates, that in Siberia he saw a child scrape up candle grease from the floor to eat, as a child with us might scrape up molasses. He gave it three tallow candles, several pounds of frozen sour butter, and a large piece of yellow soap. All were eaten with avidity. The Yakeite or Tongousi will eat anything, however putrid or repulsive. He has seen one of them eat forty pounds of meat in a day, and three of them eat a reindeer at a meal. Captain Parry, in his Voyage to the North Pole, states the following experiment on a young Esquimaux lad, scarcely full grown, not as