In this survey of the ponds of Mexico, I have drawn upon the experience which has been acquired in the process of evaporation at the extensive salt manufactories of Syracuse and the surrounding villages in Western New York, and also the experience of our engineers Upon the Erie Canal, and the engineers upon the dikes or levees at Sacramento, where the nature of the soil resembles that of Mexico. And I may now conclude this long survey of the canals and lagunas of Mexico, by saying that it is a wise provision of Providence that all bodies of water that have no outlet are found to contain a considerable infusion of salt, otherwise their accumulations of decaying matter would be such that mankind could not live in their vicinity. This valley is an illustration of that truth. Tezcuco, surrounded by barrenness, is not deleterious to life, while the fresh-water lagunas, though continually changing their volume, render Mexico unhealthy in summer by the gases which they exhale from decaying vegetation.
ANCIENT POPULATION OF THE VALLEY.
I have pretty thoroughly described this small valley, and have also stated how large a portion of it is flooded with surface-water, and how large a portion of this water is infused with salt. In the vicinity of Tacubaya the land is remarkably fertile, and there is good tillable land as the mountains are approached, especially about Chalco on the southeast; but under Indian cultivation, the whole of this valley could have produced sustenance for only an extremely limited population, if the product of the floating gardens and the ducks caught upon the pond should be added. It is totally inadequate to feed the population of Mexico under the vice-kings, 400,000, or its present population of say 300,000; nor could the valley itself be made to sustain one third of this. This valley, it must be recollected, is inclosed on all sides except the north by mountains that exceed 10,000 feet in height, while the commissariat capacity of barbaric tribes is not such as to provide extensive supplies from a distance. Under such circumstances, we should look for an extremely limited population. Yet the most surprising part of the story of the conquest is the enormous population assigned to the numerous large cities which they allege the valley contained. Diaz says, "A series of large towns stretched themselves along the banks of the lake, out of which [the lake] still larger ones rose magnificently above the water." Cortéz says that Iztapalapan contained "10,000 families," which would give the town 50,000 inhabitants; "Amaqueruca, 20,000 inhabitants;" "Mexicalzingo, 3000 families," or 15,000 inhabitants; "Ayciaca more than 6000 families;" "Huchilohuchico, 5000 or 6000." The population of Chalco he does not give, nor the population of the very numerous villages whose names he mentions. At the present day there are a few mud huts in nearly every locality named, but not enough in any one instance to merit the name of a village. And this, I am inclined to believe, was the real condition of things in the time of Cortéz. The city of Mexico alone would have exhausted the limited resources of the valley. Old Thomas Gage was as much puzzled two hundred years ago to account for this astonishing disappearance of the numerous Indian cities of this valley as we are, and also for the supposed filling up of the lakes, never appearing to suspect that the story of Cortéz was a fiction.
CHAPTER XVI.
The Chinampas or Water Gardens.—Laws of Nature not set aside.—Mud will not float.—The present Chinampas.—They never could have been floating Gardens.—Relations of the Chinampas to the ancient State of the Lake in the Valley.
All the world has heard of the floating gardens (chinampas) of Mexico, but all the world has not seen them. I have not seen any floating gardens, nor, on diligent inquiry, have I been able to find a man, woman, or child that ever has seen them, nor do I believe that such a thing as a floating garden ever existed at Mexico. Humboldt admits that they do exist; says that he has seen floating earthy masses of great size in the tropical rivers, and then describes the manner of the construction of the chinampas, but in such a way as to satisfy the careful reader that he does not intend to say that he saw them himself, and evidently makes his statement upon hearsay; and takes it up as an admitted fact, without having his mind called to the physical impossibilities of floating a mass of earth that was of a greater specific gravity than water.
FAITH AND TESTIMONY.
When the historians of the Conquest wrote their marvelous narratives of alleged adventures and of the new empire, it was a question for the Emperor and the Inquisition solely, whether their writings should pass for history or be condemned as fabulous. With this question the people had nothing to do but to believe as it suited those in authority. The question being settled that the publication of the letters of Cortéz as a verity would redound to the glory of the Church and the king, then it was also settled that there should be no contradiction published; and as these marvelous tales were spread abroad throughout Europe, with the masses of silver from the newly-discovered mines, men were prepared to believe almost any thing—even that rich vegetable mould, when saturated with water, could float.
It not being lawful to promulgate the facts of the Conquest, the memory of events that really transpired ultimately passed from the recollections of men, so that the letters of Cortéz were taken for truth, even in their most minute details; so that, in a subsequent century, we find a vice-king employing an engineer to search for and clean out the hole in the bottom of the Tezcuco! for, from the vice-king down to the most insignificant official, all assumed that the letters of Cortéz gave a correct picture of affairs at that time; and all showed the greatest embarrassment in accounting for the magnitude of the changes that are supposed to have occurred without a sufficiently adequate cause. It is a common difficulty in all purely Catholic countries, for there the rule of evidence is an unnatural one. The people have been taught to believe from their infancy that the laws of nature can be set aside upon every trifling occasion, at the momentary caprice of any one of the multitude of saints "who are to govern the world;" and on proof that any mortal has set aside the laws of nature or wrought a miracle, he at once becomes a saint. With these "dutiful children of the Church" there can be no fixed laws of evidence; the only ground of belief is, and ever must be, Has the statement been sanctioned by the highest authority? If so, it is true; if not, it is to be doubted, however positive the proofs may be. A difficulty that the traveler every where encounters is that he can believe nothing that he hears, even on the most trifling subject, without careful examination and weighing of testimony. As he can not examine every thing himself, he is constantly liable to be imposed upon by taking for granted that which is every where affirmed. Humboldt for once, with all his caution, seems to have fallen into the common trap, and credited, without examination, the story of the floating gardens.