Section II.—The Earth.
Surface of the Earth — Mountains — Fertility of Plants — Dissemination of Seeds — Preservation of Plants — Adaptation to different Climates — Number of vegetables — Succession of vegetables — Remarkable Trees — Sensitive Plants — Kitchen vegetables — Garden flowers — Religious Improvement.
The dry land and the seas constitute what is called the terraqueous globe; what proportion the superficies of the sea bears to that of the land, cannot be easily ascertained; but, as one observes, the earth and the water exist in a most judicious proportion to each other. According to the most exact calculations, the surface of the earth is 199,512,595 square miles; and that of the sea is to the land as three to one. There is no certain measurement of the proportion of land and water which the parts within the polar circles contain. The superficies of the sea appearing so large, may lead some persons to suppose, that the proportions between the land and water are not wisely adjusted; and that had there been less sea and more dry land, this would have been more adapted to the accommodation and service of mankind. As such a supposition as this tends to arraign the wisdom of God, so it proceeds from ignorance of natural philosophy. For, as Dr. Keill asserts, “if there were but half the sea that now is, there would be also only half the quantity of vapors; and, consequently, we could have no more than half so many rivers as there now are, to supply not only all the dry land we have at present, but half as much more; for the quantity of vapors which are raised, bears a proportion to the surface whence they are raised, as well as the heat which raised them. The wise Creator so prudently ordered it, that the sea should be large enough to supply vapors sufficient for all the land, which it would not do if it were less than it now is.”[97] The Scriptures speak of God as making all things in number, weight, and measure; as proceeding in his works with the greatest exactness. “He hath measured the waters in the hollow of his hand, and meted out heaven with a span, and comprehended the dust of the earth in a measure, and weighed the mountains in scales, and the hills in a balance.” Those who wish to see this further illustrated, would do well to consult Ray’s “Wisdom of God manifested in the works of the Creation,” and his “Physico-theological Discourses.”
The stately mountains, that lift their lofty heads above the clouds, serve for very beneficial purposes. Does the bold atheist call them blemishes, and irregularities in the formation of the earth? Surely he never considered how necessary they are, for arresting the clouds in their flight, and conveying their waters through imperceptible channels, till they meet in some common receptacle, whence they burst out in springs to fertilize the lower grounds, and afford refreshing streams for man and beast. “This,” says Mr. Halley, “seems to be the design of the hills, that their ridges, being placed through the midst of the continents, might serve as it were for alembics, to distil fresh water for the use of man and beast; and that their heights might give a descent to those streams to run gently, like so many veins of the microcosm, to be more beneficial to the creation.” They are, says Mr. Ray, “for the generation and maintenance of rivers and fountains, which—on the hypothesis that all proceed from rain water—could not subsist without them, or but rarely. So we should have only torrents, which would fail in summer, or in any dry season, and nothing to trust to, but stagnating water, reserved in pools and cisterns. The great inconvenience resulting from this I need not take pains to show. I say that fountains and rivers would be but rare, were there no mountains. For the whole dry land being but one continued mountain, and ascending all along from the sea to the mid-land, as is undeniably proved by the descent of rivers even in plain countries; the water sinking into the earth, may run under ground, and, according as the vein leads it, break out in the side of this mountain, though the place, as to outward appearance, be a plain. There are huge ridges and extended chains of mountains directed for the most part to run east and west; by which means they give admittance and passage to the vapors, brought by the winds from the Atlantic and Pacific oceans; but stop and inhibit their excursions to the north and south, either condensing them on their sides into water, by a kind of external distillation; or by straitening and constipating them, compelling them to gather into drops, or descend down in the rain.”
After the waters had subsided, the land appeared, dry and fit for vegetation. “And God said, Let the earth bring forth grass, the herb yielding seed, and the fruit-tree yielding fruit after his kind, whose seed is in itself upon the earth: and it was so. And the earth brought forth grass, and herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after his kind.” Here we rise to organized and vegetative bodies. At the Divine command, herbs, plants, trees, and all the almost endless varieties of the vegetable world, bearing their several seeds and fruits, according to their different kinds, immediately began to appear. Thus before God formed any living creature to dwell upon the earth, he provided abundantly for its sustenance. “Now as God delights to manifest himself in the little as well as the great,” says a celebrated commentator, “he has shown his consummate wisdom in every part of the vegetable creation. Who can account for, or comprehend, the structure of a single tree or plant? The roots, the stem, the woody fibres, the bark, the rind, the air-vessel s, the sap-vessels, the leaves, the flowers, and the fruits, are so many mysteries. All the skill, wisdom, and power of men and angels, could not produce a single grain of wheat!”
Dr. Hales, in his Statistical Essays, has observed, that the substances of vegetables appear, by a chemical analysis, to be composed of sulphur, volatile salt, water, and earth, which are all endued with mutually attracting powers; and also of a large portion of air, which has a wonderful power of strongly attracting in a fixed state, or of repelling in an elastic state, with a power which is superior to great compressive forces.[98] By the infinite combinations, action, and reaction of these principles, all the operations in animal and vegetable bodies are effected. These active aërial principles are very serviceable in carrying on the work of vegetation to its perfection and maturity; not only in helping, by their elasticity, to distend each ductile part, but, also, by enlivening and invigorating their sap, where, mixing with the other mutually attracting principles, they are, by gentle heat and motion, set at liberty to assimilate into the nourishment of the respective parts. The sum of the attracting powers of these mutually acting and re-acting principles, is, while in this nutritive state, superior to their repelling power; by which the work of nutrition is gradually advanced by the nearer and nearer union of these principles from a less to a greater degree of consistency, till they are advanced to that viscid, ductile state, whence the several parts of vegetables are formed; and are, at length, firmly compacted into hard substances, by the flying off of the watery diluting vehicle: but when they are again disunited by the watery particles, their repelling power is thereby become superior to their attracting power, and the union of the parts of vegetables is so thoroughly dissolved, that putrefaction commences.
God has endued the vegetable creation with the astonishing power of multiplying itself by seeds, slips, roots. &c. ad infinitum: it contains in itself all the rudiments of the future plants through their endless generations. The celebrated Linnæus, in an “oration concerning the augmentation of the habitable earth,” which proceeds on the supposition of the existence of a sexual system in the vegetable world, shows how from one plant of each species the immense number of individuals now existing might arise. He gives some instances of the surprising fertility of certain plants; as, of the elecampane, one plant of which produced 3,000 seeds; of spelt, 2,000; of the sun-flower, 4,000; of the poppy, 3,200; of tobacco, 40,320: and one grain of Turkey-corn produces 2,000 others! But supposing any annual plant producing yearly only two seeds, even of these, after 20 years, there would be 1,048,576 individuals. For they would increase yearly in a double proportion, viz. 2, 4, 8, 16, 32, &c. The seed of the elm, as a learned author observes, affords a remarkable instance of the prolific power with which the vegetable creation is endued, to multiply its different species. “This tree produces one thousand five hundred and eighty-four millions of seeds; and each of these seeds has the power of producing the same number. How astonishing is this produce! At first one seed is deposited in the earth; from this one a tree springs, which in the course of its vegetative life produces one thousand five hundred and eighty-four millions of seeds. This is the first generation. The second generation will amount to two trillions, five hundred and ten thousand and fifty-six billions. The third generation will amount to fourteen thousand six hundred and fifty-eight quadrillions, seven hundred and twenty-seven thousand and forty trillions! And the fourth generation from these would amount to fifty one sextillions, four hundred and eighty-one thousand three hundred and eighty-one quintillions, one hundred and twenty-three thousand one hundred and thirty-six quadrillions! Sums too immense for the human mind to conceive; and when we allow the most confined space in which a tree can grow, it appears that the seeds of the third generation from one elm would be many myriads of times more than sufficient to stock the whole superficies of all the planets in the solar system!”
While many plants and trees may be propagated by branches, buds, suckers, and leaves fixed in the ground; so concerning the dissemination of seeds after they come to maturity, the Author of nature has wisely provided in various ways; this being absolutely necessary, since without it no crop could follow. The stalks and stems favor this purpose; for these raise the fruit above the ground, so that the winds, shaking them to and fro, widely disperse the ripe seeds. The pericarpium, a pellicle or thin membrane encompassing the fruit or grain of a plant, is generally shut at the top, that the seeds may not fall before they are shaken out by stormy winds. Wings are given to many seeds, by the help of which they fly far from the mother plant, and frequently spread over a large tract of country. These wings consist either of down, as in most of the composite-flowered plants; or of a membrane, as in birch, alder, ash, &c. Several kinds of fruits are endued with a remarkable elasticity, by the force of which the ripe pericarpies throw the seeds to a great distance; as wood-sorrel, spurge, phyllanthus, and dittany. Other seeds or pericarpies are rough, or provided with hooks, as hounds-tongue, agrimony, &c; so that they are apt to stick to animals which pass by them, and by this means are carried to their holes, where they are both sown and manured. Berries, as well as other pericarpies, are by nature allotted for aliment to animals; but, with this condition, that while they eat the pulp, they shall sow the seeds: for when they feed on it, they either disperse them at the same time; or, if they swallow them, they are returned unhurt. The mistletoe always grows on other trees, because the thrush eating its seeds, casts them forth with its dung. The cross-bill living on fircones, and the haw-finch feeding on pinecones, sow many of their seeds.
The structure of plants contributes essentially both to their own preservation, and that of others. But the wisdom of the Creator appears very remarkable in the manner of the growth of trees. For as their roots descend deeper than those of other plants, provision is thereby made that they shall not rob them too much of nourishment;[99] and what is still more, a stem, not above a span in diameter, often shoots its branches very high; these bear perhaps many thousand buds, each of which is a plant, with its leaves, flowers, and stipulæ. Now if all these grew on the plain, they would take up a thousand times as much space as trees do; and, in this case, there would scarcely be room in all the earth for so many plants as at present trees alone afford. Besides, plants that shoot up in this way are more easily preserved from cattle by a natural defence: their leaves also, falling in autumn, cover the plants growing about them against the rigor of the winter; and, in the summer, they afford a pleasing shade, not only to animals, but to plants, against the intense heat of the sun. We may add, that trees, like all other vegetables, imbibe water from the earth: which does not circulate again to the root, but being dispersed like small rain, by the transpiration of the leaves, moistens the plants that grow around. Many plants and shrubs are armed with thorns, as the buckthorn, sloe, carduus, cotton-thistle, &c: these serve to keep off animals, which otherwise would destroy their fruit. At the same time, they cover many other plants, especially of the annual kind, under their branches. Nay it has frequently been observed on commons where furze grows, that wherever a bush was left untouched for some years by the inhabitants a tree has sprung up, being secured by the prickles of that shrub from the bite of cattle. So that while adjacent grounds are robbed of plants by voracious animals, some may be preserved to ripen flowers and fruit, and stock the surrounding parts with seeds which otherwise would be quite extirpated. All herbs cover the ground with their leaves, and by their shade hinder it from being totally deprived of that moisture which is necessary to their nourishment. Mosses, which adorn the most barren places, do, at the same time, preserve lesser plants when they begin to shoot, from cold and drought; as is evident in gardens, where plants are preserved in the same way. They also hinder the fermenting earth from forcing the roots of plants upwards in the spring; like what happens annually to trunks of trees, and other things put into the ground. Hence very few mosses grow in warm climates, the same necessity not existing in those places.