CHAPTER VIII. EARTH, AIR, AND WATER IN RELATION TO MAN—HOW MODIFIED BY HIM—RESULTS OF THAT MODIFICATION—ACTION AND REACTION.
§ 1. The question of acclimation is not confined merely to man’s transfer from one country to another, and to his attempts to accommodate himself to the new locality, to the altered circumstances of his adopted country. As civilized man traverses the earth in search of new abodes, he carries with him the arts of social life, and especially the art of agriculture, by which alone he can exist in congregated masses: agriculture, which forms indeed the very basis of civilization.
Whether we view man as a native of the land or a stranger, he cannot evade this question; for even as a native and as an individual of a race whose presence on the soil he may inhabit precedes the records of authentic history, if he form a portion of civilized society he receives from his ancestors or predecessors a system he is bound to improve, or at least to maintain, so that he shall live and thrive, not as the beasts of the field, but as a member of a civilized people. When a hunting tribe of North American Indians, a horde of Bedouins, or Hottentots or Caffres, a Turcoman family, or a gipsy encampment, a Cape Boer, or an Australian sheep-farmer, sit down by stream, or valley, or lake, they no more influence the soil than a troop of antelopes or buffaloes. Nature’s great processes go on unaffected: they deteriorate, it is true, by respiration, the superincumbent atmosphere, but not more than any equal amount of animal life. This deterioration the wild plants around, sown by nature herself, speedily removes; the oxygen consumed by savage man and the animal life around, equally wild, is speedily renovated by vegetation, and the oxygen they remove from the atmosphere and the carbonic acid they pour into it, rapidly and constantly recover their equilibrium under the influence of vegetation. Thus, neither the earth (soil), air, nor water, is in any way influenced by his presence, nor is he in general affected by these; there is no reciprocal influence for good or bad: he cuts down no forests, grows no wheat, or but little, makes no canals, drains no marsh-lands, poisons no rivers; the refuse of his dwellings, the excreta of such a population, are not sensibly perceived, even if allowed to rot and waste away on the surface—a practice prevalent with most if not all wild and uncultivated people; it rapidly disappears, disintegrated by processes in which the lower forms of animal life take a part. Now, contemplate the picture civilized man presents, and see him in direct antagonism with nature! The plants of nature’s sowing are rudely torn up with the plough and destroyed, the fields are forced to yield crops by which he lives, and what he takes from the soil must, to use the language of chemists, “be restored to it:” the excreta of man and animals, the refuse of dwellings, the deteriorated and poisoned liquids, the products of manufactories, are collected into heaps, to rot on the surface of the soil, before being dug into it; or are thrown into the rivers, to poison, in a certain sense, the waters on which man lives, rendering their banks, if not pestilential, at least most unpleasant as human abodes; canals are dug, vast reservoirs are formed, which in time give rise by mismanagement to fevers, intermittent and others; the minerals of the earth are quarried and placed on the soil, mines are dug, and from them waters are discharged into the neighbouring streams, strongly poisoned with the metallic ores. To imagine that an influence thus affecting earth, air, and water can proceed and increase without affecting human life, can be overcome by habit, does not require to be met by counter-influences originating in the experience and reasoning of man himself, is a supposition which the history of large cities refutes. The influence is reciprocal. When man thus acts on the three elements of nature by which he lives, they react on him, and it is this reaction he is called on to meet and to overcome as best he can. It is a question of reason and experiment—that is, of science and of simple observation; simple observation and experiment taught the native Peruvians the value of guano, for science had at that time no standing on the American continent; and now the chemist steps in and explains why it was that the experiment proved successful. Whether his explanation be satisfactory or not, touches not the question; though proved to be erroneous in a single instance, as it possibly is in regard of this very Peruvian guano, science stands on too secure a basis to require any defence from me.
It is one of the conditions of civilization, that man must everywhere accept the social system within which he lives. Whether a dweller in detached cottages and farm-houses, or congregated into townships and villages; collected in masses, as in towns and cities, his endeavour is to protect his dwelling from all that is offensive and from whatever may prove injurious to the health of himself and family. An ancient adage tells us not to act contrary to nature; but as nature reveals nothing to us, as her intentions can only be read by the lights of science and reason, or science based on observation and experiment, whence human reason draws deductions conformable with its power, so is it most difficult for man to say what is best to be done under all circumstances. When a man builds a cottage, a house, or a palace, after duly attending to the surface-drains, he constructs near his dwelling, sometimes beneath it, a cesspool and a dead-well, the former intended to receive the more solid excreta, the latter the soil-water of the kitchen—the water, in fact, used in the domestic economy of the house. If the dead-well or pit dug to receive the soiled water of the house be sufficiently deep, it filters through the soil, and thus requires no clearing out—if not, it overflows the court or garden, and speedily renders the place uninhabitable. The cesspool, if deep enough and properly secured, remains for many years unknown and unperceived, until filled; it may even be forgotten altogether, and its very existence remain unknown, until disclosed by accident; but whatever be its age or condition, so soon as its contents are exposed to the air, it is found to have continued unaltered; and if spread on the fields, as I have seen done, renders the vicinity for some time unendurable, thus proving the sagacity of the Jewish legislator in his instructions to that people to whom he gave laws and regulations to serve them for all time to come.[34]
If the adage I have quoted above be true—namely, that we must not act contrary to nature—there is another of the truth of which we feel more assured. It is this: whenever man interferes with nature, he must take the whole matter on himself, and be prepared to meet every contingency. Nature gave us streams and rivers more or less pure, whose banks are more or less salubrious. If man pours into these streams and rivers the refuse of towns and cities, he must be prepared to meet the result of the experiment. It may be good—it may be bad to him: this he cannot know beforehand; but reason tells him that the experiment is likely to prove injurious. It may be less injurious than burying the excreta in cesspools under his house, or court, or garden;[35] but this I doubt. In the meantime, how does civilized man protect himself from a source of disease respecting which there never was a doubt—the natural humidity of the soil on which he has erected his dwelling, in which he sleeps and lives? To meet this evil he forms surface drains around his house and garden and court. Into these collect the humidity natural to the soil, as well as rains of heaven. These drains, adulterated by no intermixture with the refuse of house and stables, terminate in the nearest streams, and serve to maintain these streams and rivers into which they flow at their natural standard.
Thus, before it was discovered that the best way of dealing with these difficult questions was to break down the distinction between drain and sewer (thus poisoning, probably for all time to come, the air of towns and cities), construct a sewer which soon becomes a cloaca to receive all, and in open day and above ground throw the contents into the nearest stream—imitating old Rome, without knowing anything of Rome’s municipal economy, our forefathers drew a marked and clear distinction—1st, between drain and sewer; 2nd, between a cesspool and a dead-well; 3rd, between the excreta of man, which they knew to be offensive, and that of animals, which all were well aware are innoxious: the latter they restored to the fields, the former they disposed of as best they could.
Society, having rejected in this instance the experience of their forefathers, enters now on a new phasis. Nature, about which they talk so much, will not suffer them to rest half way. Bad odours pervade the streets, courts, and houses: rivers can scarcely be approached. Chemists affirm that that which is thrown into the sea should be returned to the land. It is this question, in so far as it bears on the matter discussed in this chapter, I shall now briefly discuss.
There lie before me the “Letters on Chemistry” of an illustrious German chemist.[36] They contain the expression of the latest scientific results hitherto attained. Whatever view those who follow us may adopt, we must in the meantime accept, to a certain extent, of those contained in these “Letters.” A phenomenon must be accepted as a fact until refuted by another; and the last experiment, until refuted, expresses the nearest approach to that truth which, up to the moment, man had been able to attain. Simple observation tells man many truths. It shows him that out of grass, herbivora, or grass-eating animals of all kinds—from the timid hare to the swift and powerful horse—from the fierce buffalo to the sagacious and irresistible elephant—find the means for forming muscle and bones, viscera and skin. Out of a similar food man himself, though no doubt omnivorous, can also derive the means of support. The rice-eating population of India are not deficient in energy; whilst it is equally certain, though less surprising, no doubt, that out of that which once was a living animal, man and the carnivora derive a considerable part of their subsistence.
No experiments can set aside these simple views, which indeed form the basis of all inquiry; but civilized man, as I have shown, appeals to the soil mainly for support. He trusts to the cerealia, and to those exuberant and abundant crops of legumina and of grains required for the support of herds of animals, which the uncultivated field could never maintain. Hence arose agriculture, the most useful of all the practical arts—not yet a science, but likely in time to become one.
Chemists assert—and I see no reason to doubt their experiments—that the ash of the blood of graminivorous animals is identical with that of the ash of grain; the incombustible constituents of the blood of men, and of such animals as consume a mixed food, are the constituents of the ashes of bread, flesh, and vegetables; the carnivorous animal contains in its blood the constituents of the ash of flesh.[37] All these substances ought to be found in grass alone.