From this abundance of the national food, there resulted a train of events strictly analogous to those which took place in India. In Africa generally, the growth of population, though on the one hand stimulated by the heat of the climate, was on the other hand checked by the poverty of the soil. But on the banks of the Nile this restraint no longer existed,[146] and therefore the laws already noticed came into uncontrolled operation. By virtue of those laws, the Egyptians were not only satisfied with a cheap food, but they required that food in comparatively small quantities; thus by a double process, increasing the limit to which their numbers could extend. At the same time the lower orders were able to rear their offspring with the greater ease, because, owing to the high rate of temperature, another considerable source of expense was avoided; the heat being such that, even for adults, the necessary clothes were few and slight, while the children of the working classes were entirely naked; affording a striking contrast to those colder countries where, to preserve ordinary health, a supply of warmer and more costly covering is essential. Diodorus Siculus, who travelled in Egypt nineteen centuries ago, says, that to bring up a child to manhood did not cost more than twenty drachmas, scarcely thirteen shillings English money; a circumstance which he justly notices as a cause of the populousness of the country.[147]

To compress into a single sentence the preceding remarks, it may be said that in Egypt the people multiplied rapidly, because while the soil increased their supplies, the climate lessened their wants. The result was, that Egypt was not only far more thickly peopled than any other country in Africa, but probably more so than any in the ancient world. Our information upon this point is indeed somewhat scanty, but it is derived from sources of unquestioned credibility. Herodotus, who the more he is understood the more accurate he is found to be,[148] states that in the reign of Amasis there were said to have been twenty thousand inhabited cities.[149] This may, perhaps, be considered an exaggeration; but what is very observable is, that Diodorus Siculus, who travelled in Egypt four centuries after Herodotus, and whose jealousy of the reputation of his great predecessor made him anxious to discredit his statements,[150] does nevertheless, on this important point, confirm them. For he not only remarks that Egypt was at that time as densely inhabited as any existing country, but he adds, on the authority of records which were then extant, that it was formerly the most populous in the world, having contained, he says, upwards of eighteen thousand cities.[151]

These were the only two ancient writers who, from personal knowledge, were well acquainted with the state of Egypt;[152] and their testimony is the more valuable because it was evidently drawn from different sources; the information of Herodotus being chiefly collected at Memphis, that of Diodorus at Thebes.[153] And whatever discrepancies there may be between these two accounts, they are both agreed respecting the rapid increase of the people, and the servile condition into which they had fallen. Indeed, the mere appearance of those huge and costly buildings, which are still standing, are a proof of the state of the nation that erected them. To raise structures so stupendous,[154] and yet so useless,[155] there must have been tyranny on the part of the rulers, and slavery on the part of the people. No wealth, however great, no expenditure, however lavish, could meet the expense which would have been incurred, if they had been the work of free men, who received for their labour a fair and honest reward.[156] But in Egypt, as in India, such considerations were disregarded, because everything tended to favour the upper ranks of society and depress the lower. Between the two there was an immense and impassable gap.[157] If a member of the industrious classes changed his usual employment, or was known to pay attention to political matters, he was severely punished;[158] and under no circumstances was the possession of land allowed to an agricultural labourer, to a mechanic, or indeed to any one except the king, the clergy, and the army.[159] The people at large were little better than beasts of burden; and all that was expected from them was an unremitting and unrequited labour. If they neglected their work, they were flogged; and the same punishment was frequently inflicted upon domestic servants, and even upon women.[160] These and similar regulations were well conceived; they were admirably suited to that vast social system, which, because it was based on despotism, could only be upheld by cruelty. Hence it was that, the industry of the whole nation being at the absolute command of a small part of it, there arose the possibility of rearing those vast edifices, which inconsiderate observers admire as a proof of civilization,[161] but which, in reality, are evidence of a state of things altogether depraved and unhealthy; a state in which the skill and the arts of an imperfect refinement injured those whom they ought to have benefited; so that the very resources which the people had created were turned against the people themselves.

That in such a society as this, much regard should be paid to human suffering, it would indeed be idle to expect.[162] Still, we are startled by the reckless prodigality with which, in Egypt, the upper classes squandered away the labour and the lives of the people. In this respect, as the monuments yet remaining abundantly prove, they stand alone and without a rival. We may form some idea of the almost incredible waste, when we hear that two thousand men were occupied for three years in carrying a single stone from Elephantine to Sais;[163] that the Canal of the Red Sea alone, cost the lives of a hundred and twenty thousand Egyptians;[164] and that to build one of the pyramids required the labour of three hundred and sixty thousand men for twenty years.[165]

If, passing from the history of Asia and Africa, we now turn to the New World, we shall meet with fresh proof of the accuracy of the preceding views. The only parts of America which before the arrival of the Europeans were in some degree civilized, were Mexico and Peru;[166] to which may probably be added that long and narrow tract which stretches from the south of Mexico to the Isthmus of Panama. In this latter country, which is now known as Central America, the inhabitants, aided by the fertility of the soil,[167] seem to have worked out for themselves a certain amount of knowledge; since the ruins still extant, prove the possession of a mechanical and architectural skill too considerable to be acquired by any nation entirely barbarous.[168] Beyond this, nothing is known of their history; but the accounts we have of such buildings as Copan, Palenque, and Uxmal, make it highly probable that Central America was the ancient seat of a civilization, in all essential points similar to those of India and Egypt; that is to say, similar to them in respect to the unequal distribution of wealth and power, and the thraldom in which the great body of the people consequently remained.[169]

But although the evidence from which we might estimate the former condition of Central America is almost entirely lost,[170] we are more fortunate in regard to the histories of Mexico and Peru. There are still existing considerable and authentic materials, from which we may form an opinion on the ancient state of those two countries, and on the nature and extent of their civilization. Before, however, entering upon this subject, it will be convenient to point out what those physical laws were which determined the localities of American civilization; or, in other words, why it was that in these countries alone, society should have been organized into a fixed and settled system, while the rest of the New World was peopled by wild and ignorant barbarians. Such an inquiry will be found highly interesting, as affording further proof of the extraordinary, and indeed irresistible, force with which the powers of nature have controlled the fortunes of man.

The first circumstance by which we must be struck, is that in America, as in Asia and Africa, all the original civilizations were seated in hot countries; the whole of Peru proper being within the southern tropic, the whole of Central America and Mexico within the northern tropic. How the heat of the climate operated on the social and political arrangements of India and Egypt, I have attempted to examine; and it has, I trust, been proved that the result was brought about by diminishing the wants and requirements of the people, and thus producing a very unequal distribution of wealth and power. But, besides this, there is another way in which the average temperature of a country affects its civilization, and the discussion of which I have reserved for the present moment, because it may be more clearly illustrated in America than elsewhere. Indeed, in the New World, the scale on which Nature works, being much larger than in the Old, and her forces being more overpowering, it is evident that her operations on mankind may be studied with greater advantage than in countries where she is weaker, and where, therefore, the consequences of her movements are less conspicuous.

If the reader will bear in mind the immense influence which an abundant national food has been shown to exercise, he will easily understand how, owing to the pressure of physical phenomena, the civilization of America was, of necessity, confined to those parts where alone it was found by the discoverers of the New World. For, setting aside the chemical and geognostic varieties of soil, it may be said that the two causes which regulate the fertility of every country are heat and moisture.[171] Where these are abundant, the land will be exuberant; where they are deficient, it will be sterile. This rule is, of course, in its application subject to exceptions, arising from physical conditions which are independent of it; but if other things are equal, the rule is invariable. And the vast additions which, since the construction of isothermal lines, have been made to our knowledge of geographical botany, enable us to lay this down as a law of nature, proved not only by arguments drawn from vegetable physiology, but also by a careful study of the proportions in which plants are actually distributed in different countries.[172]

A general survey of the continent of America will illustrate the connexion between this law and the subject now before us. In the first place, as regards moisture, all the great rivers in the New World are on the eastern coast, none of them on the western. The causes of this remarkable fact are unknown;[173] but it is certain that neither in North, nor in South America, does one considerable river empty itself into the Pacific; while on the opposite side there are numerous rivers, some of enormous magnitude, all of great importance, as the Negro, the La Plata, the San Francisco, the Amazon, the Orinoco, the Mississippi, the Alabama, the Saint John, the Potomac, the Susquehannah, the Delaware, the Hudson, and the Saint Lawrence. By this vast water-system the soil is towards the east constantly irrigated:[174] but towards the west there is in North America only one river of value, the Oregon;[175] while in South America, from the Isthmus of Panama to the Straits of Magellan, there is no great river at all.

But as to the other main cause of fertility, namely heat, we find in North America a state of things precisely the reverse. There we find that while the irrigation is on the east, the heat is on the west.[176] This difference of temperature between the two coasts is probably connected with some great meteorological law; for in the whole of the northern hemisphere, the eastern part of continents and of islands is colder than the western.[177] Whether, however, this is owing to some large and comprehensive cause, or whether each instance has a cause peculiar to itself, is an alternative, in the present state of knowledge, impossible to decide; but the fact is unquestionable, and its influence upon the early history of America is extremely curious. In consequence of it, the two great conditions of fertility have not been united in any part of the continent north of Mexico. The countries on the one side have wanted heat; those on the other side have wanted irrigation. The accumulation of wealth being thus impeded, the progress of society was stopped; and until, in the sixteenth century, the knowledge of Europe was brought to bear upon America, there is no instance of any people north of the twentieth parallel, reaching even that imperfect civilization to which the inhabitants of India and of Egypt easily attained.[178] On the other hand, south of the twentieth parallel, the continent suddenly changes its form, and, rapidly contracting, becomes a small strip of land, until it reaches the Isthmus of Panama. This narrow tract was the centre of Mexican civilization; and a comparison of the preceding arguments will easily show why such was the case; for the peculiar configuration of the land secured a very large amount of coast, and thus gave to the southern part of North America the character of an island. Hence there arose one of the characteristics of an insular climate, namely, an increase of moisture caused by the watery vapour which springs from the sea.[179] While, therefore, the position of Mexico near the equator gave it heat, the shape of the land gave it humidity; and this being the only part of North America in which these two conditions were united, it was likewise the only part which was at all civilized. There can be no doubt that if the sandy plains of California and southern Columbia, instead of being scorched into sterility, had been irrigated by the rivers of the east, or if the rivers of the east had been accompanied by the heat of the west, the result of either combination would have been that exuberance of soil by which, as the history of the world decisively proves, every early civilization was preceded. But inasmuch as, of the two elements of fertility, one was deficient in every part of America north of the twentieth parallel, it followed that, until that line was passed, civilization could gain no resting-place; and there never has been found, and we may confidently assert never will be found, any evidence that even a single ancient nation, in the whole of that enormous continent, was able to make much progress in the arts of life, or organize itself into a fixed and permanent society.