There are these germs of plants, and young plants which move, and on the other hand, almost all the adult zoophytes, sponges, corals, madrepores, sea-stars, byssus, &c., &c., to which we may add several mollusca (all those in shells), are fixed to the earth. In these cases we must take the plant for the animal, and the animal for the plant, if we positively hold by voluntary motion as an absolute distinction between animals and plants.
On the borders of the two kingdoms,—when we consider zoophytes in the animal, and cryptogams in the vegetable kingdom,—there is no longer, so to speak, either animal or plant; the two seem to be confounded, and fused together.
If, before the discovery of the fresh-water polype, thatliving creature had been presented to a naturalist, he would have felt puzzled how to class it. Seeing it multiplying itself by buds, by offshoots, by engraftment, he would doubtless have declared that this organized being was a plant. But if he had been made to remark that this same creature fed on living prey, which it seized and swallowed, that it had long and flexible arms, of which it formed a kind of net for the purpose of seizing this prey, which it conveyed into the interior of a digestive tube, our naturalist would have made haste to place the polype in the ranks of the animals. He would have been asked to observe that the polype may be turned inside out, like a glove, so that his interior skin becomes his exterior skin, and that, thus turned inside out, he lives, grows, and multiplies himself, precisely as he does before this curious reversal. Our naturalist, much embarrassed in the presence of so unheard of a fact, would doubtless immediately have begun to seek some intermediate kingdom between the animal and the vegetable, to which he might relegate this paradoxical being, which could not, with absolute certainty, be classed either with plants, or with animals.
The fact is, classifications are products of human science, nature knows nothing about them. We descend, by insensible degrees, from one kingdom to the other; we go from the man to the polype, and from the polype to the rose tree, by infinite gradations, and, on the confines of the two kingdoms, there is a whole series of creatures which it is very difficult to range under any system. For how long did naturalists hesitate before they regarded infusoria, coral,sponges, star-fish, gorgons, sea-anemones, and madrepores as animals? Even in the present day micrographers who study the microscopic beings proper to vegetable and animal infusions, such as the monads, polypoid worms, and numerous others, find the utmost difficulty in assigning these creatures to such or such a kingdom, and they sometimes decide rather arbitrarily upon placing them among animals or plants.
From all the considerations, all the facts which we have just advanced, we conclude that the sensibility of plants is not to be contested, since no one can think of denying that privilege to certain zoophytes which can with difficulty be distinguished from vegetables.
We see an imposing tree, a stately oak with sturdy branches, growing on the sea coast. Not far off, on the sand of the shore, lies a star-fish flung there by the waves. A few yards below, on the surface of the water, floats a sponge, a branch of coral, a madrepore. When the icy wind blows, when the hurricane lifts the angry waves, which is it, the animal or the plant that will manifest sensibility to the tempest? The sponge, the coral, the madrepore will remain as indifferent to the fury of the elements as the rock in which they are incrusted, or as the pebble on which the star-fish stretches out its four motionless arms. But, the majestic oak will shudder at every gust of the tempest; he will bend his branches and shut up his leaves to shelter himself from the icy blast or the furious storm; and a mere glance at his attitude will indicate to you that an abnormal perturbationreigns in the atmosphere. Would you seriously say, in that case, that the vegetable feels nothing, and that the animal is sensible? Would you not, on the contrary, be inclined to declare that the tree is the sentient being, and that the star-fish, the sponge, the madrepore, are the creatures which are destitute of feeling?
Pause beside still water and seek for the polype or fresh-water hydra which we have just mentioned. You will find it difficult to disentangle this zoophyte from the reeds and willows which surround it. You will find, at length, a kind of membranous tube, a few centimetres in length. Is that the polype you were looking for? Is it not rather the stubble of some reed or grass plant? This living twig, with nothing to distinguish it in appearance from a herbaceous plant, is constantly fixed in the same place, like an aquatic vegetable. It makes some faint movements, consisting simply of the opening and shutting of the orifice of the tube, which solely constitutes its being. Sometimes it lengthens, sometimes it contracts itself, by stretching out membranous arms, as fine as threads, by means of which it seizes and drags towards it the water insects which chance to pass near it. This is the one single characteristic of its animality. At this rate, an aërial plant, thefly-catcher, would be just as much an animal as our polype, since it catches the insects which venture to crawl upon its leaves.
At the bottom of the sea there is a very curious zoophyte, theactinium, or sea-anemone. For a long time this creature was confounded with the plants, and held to be an oceanflower. Those who admire the beautiful, bright-coloured actinia, in the Garden of Acclimatization, in Paris, who look at them, waving on their flexible stem, shaking the coloured appendages and fringes which adorn their heads, find it hard to regard these charming queens of the waters otherwise than as real flowers. And, in fact, for ages, thesea-anemoneswere held to be marine plants.
In the last century, coral was held to be a marine shrub, and it was even believed that the flowers of the coral had been discovered. An academician of Paris, Count de Marsigli, created a European reputation for himself by this supposed discovery. Peyssonnel, a Provençal naturalist, found the utmost difficulty in opposing this idea, and in establishing the fact that these supposed flowers of the coral were in reality young corals. He had the whole Academy of Sciences against him; and his opposition to the ideas of the Academy brought him into such disgrace, that he was obliged to leave France and to go to the Antilles, where he died in obscurity as a doctor of medicine. And all this because he maintained that coral is not a plant, and does not produce flowers!
The famous Genevese naturalist, Charles Bonnet, anticipating the knowledge of our day by more than a century, has given a most interesting form to the parallel between animals and plants, in his work entitledContemplation de la Nature. We cannot resist the pleasure of quoting the following passage, in which Charles Bonnet shows in a striking manner what are the difficulties in the way of distinguishing theplant from the animal, and how those difficulties are disposed of by those who dispute the sensibility of plants:—
"Everything is graduated in nature," says Charles Bonnet, "and, in refusing to admit that plants are sentient, we force nature to make a jump without any assignable reason."We observe that feeling decreases by degrees from man to the nettle, and to the mussel, and we persuade ourselves that it stops there, because we regard these animals as the least perfect. But there are, perhaps, many degrees between the feeling of the mole and of the plant. There are, perhaps, still more between the most and the least sensible of the plants. The gradations, which we observe, ought to persuade us to this philosophy; the new beauty which it adds to the system of the world, and the pleasure to be derived from the multiplication of sentient creatures ought to contribute to induce us to admit it. I willingly admit that this philosophy is much to my taste. I love to think that those flowers which adorn our fields and our gardens with a brightness constantly renewed, those fruit trees which are so pleasant to our eyes and our palate; those majestic trees that compose the vast forests, which time seems to have respected, are so many sentient creatures partaking after their fashion in the sweetness of existence."Plants offer some facts to our observation which seem to indicate that they possess feeling, but we are not likely to perceive those facts, because of the strong persuasion that they are insensible, which has prevailed among us for so long. We ought to agree to consider the questiontabula rasa, and to subject plants to a new, impartial, and unprejudiced examination. An inhabitant of the moon, possessed of intellectual faculties like ours, but without any preconceived ideas about the insensibility of plants, would be the philosopher whom we require. Let us imagine such an observer engagedin studying the productions of our earth, and, after having given his attention to the polypes and other insects multiplied by the process of grafting, passing on to the contemplation of vegetables. He would, doubtless, take them at the period of their birth. With this view, he would sow seed of various species, and he would carefully watch their germination. Let us suppose that some of those seeds have been reversed in the sowing, the sprouting part turned downwards, the stem upwards; and the observer has the skill to distinguish one end of the seed from the other, and knows their functions. After some days, he will remark that the seed has grown into this reversed position, that the stem is turned upward, and the sprouting portion downward. He will feel no surprise; he will attribute a circumstance which is so hurtful to the life of the plant, to the mistake he has made in sowing the seed. But, continuing to observe, he will see the sprout and the stem each bending itself in the opposite direction, and trying to attain the right position. This change of direction will strike him as very remarkable, and he will begin to suspect that the organized being which he is studying is endowed with a certain amount of discernment. Too prudent, however, to pronounce upon these early indications, he will suspend his judgment and pursue his investigations. The plants whose germination our physicist has been observing, have been raised in the neighbourhood of a hedge. Thus favoured, and carefully cultivated, they have made great progress in a very short time. The soil which surrounds them at some distance is of two opposite qualities. That on the right of the plants is rich, damp, and spongy; that on the left is dry, hard, and gravelly. Our observer remarks that the roots, after having begun by extending equally on both sides, have changed their direction, and have spread out towards the rich and humid soil; over which they are stretching, and thus threateningto deprive the plants already there of their due share of nourishment. To prevent this inconvenience, he digs a ditch between the plants which he is observing and those they threaten to starve, and now he thinks he has provided against everything. But the plants, which he believes he has governed, disconcert all his precautions by extending their roots downwards, under the ditch, and gaining the other side."Surprised at this, he uncovers one of these roots, but without exposing it to heat, and holds a sponge steeped in water towards it. The root turns itself to the sponge, and when he changes its position, the root accommodates itself to each alteration."While our philosopher is meditating profoundly upon these facts, other facts equally remarkable present themselves almost simultaneously. He observes that all these plants have leaned away from the hedge, and are bending forward as though to present every portion of their bodies to the beneficent smiles of the sun. He sees that all the leaves are so turned that their upper surface is exposed to the sun, or to the fresh air, and that the lower surface is directed towards the hedge, or the ground. Former experience will have taught him that the upper surface of leaves serves chiefly as a defence for the lower surface, and that the latter is principally destined to pump up the moisture rising from the earth, and provide for the evacuation of what is superfluous. The direction of the leaves which he notices appears quite in harmony with his experiences. He studies this portion of the plant with increased attention."He remarks that the leaves of some species seem to follow the movements of the sun, so that in the morning they turn to the east, in the evening to the west. He sees that some leaves close themselves against the sun, others against the dew. He observes an analogous movement in certain flowers.Afterwards, he observes that no matter what the direction of the plants relative to the horizon has been, the direction of the leaves is always that which he has at first noticed, he bethinks him of changing this direction, and of placing the leaves in a position exactly contrary to their natural one. He has already had recourse to similar means in order to assure himself of the instinct of animals, and to ascertain its bearings. With this view he bends perpendicular plants towards the horizon, and keeps them in that position. Thus, the direction of the leaves is absolutely changed; the upper surface, which previously turned to the sun or to the fresh air, now looks towards the earth or the interior of the plant, and the lower surface, which formerly looked towards the earth or the interior of the plant, now turns to the sun, or the fresh air. But very soon all these leaves begin to move, they turn on their stem as on a pivot, and in an hour they will have resumed their former position. Our observer, wishing to assure himself whether leaves and branches when detached and plunged into water will preserve the inclinations which they manifest when upon the plant of which they formed a portion, subjects them to an experiment whose results leave him no doubt of the fact."He places wet sponges under the leaves, and he sees the leaves turn towards the sponges and endeavour to adhere to them by their lower surfaces. He also observes that certain plants, which he has shut up in his cabinet and in a cellar, have turned towards the window, or the grating respectively."Finally, the phenomena of the Sensitive Plant, its varied movements, the promptitude with which it contracts when touched, form the interesting subject which terminates his researches."Thus plentifully supplied with facts which all seem to tend to the support of belief in the sensibility of plants, which side will our philosopher take? Will he surrenderto these proofs? Will he suspend his judgment? I think he will take the first part."[16]
"Everything is graduated in nature," says Charles Bonnet, "and, in refusing to admit that plants are sentient, we force nature to make a jump without any assignable reason.
"We observe that feeling decreases by degrees from man to the nettle, and to the mussel, and we persuade ourselves that it stops there, because we regard these animals as the least perfect. But there are, perhaps, many degrees between the feeling of the mole and of the plant. There are, perhaps, still more between the most and the least sensible of the plants. The gradations, which we observe, ought to persuade us to this philosophy; the new beauty which it adds to the system of the world, and the pleasure to be derived from the multiplication of sentient creatures ought to contribute to induce us to admit it. I willingly admit that this philosophy is much to my taste. I love to think that those flowers which adorn our fields and our gardens with a brightness constantly renewed, those fruit trees which are so pleasant to our eyes and our palate; those majestic trees that compose the vast forests, which time seems to have respected, are so many sentient creatures partaking after their fashion in the sweetness of existence.
"Plants offer some facts to our observation which seem to indicate that they possess feeling, but we are not likely to perceive those facts, because of the strong persuasion that they are insensible, which has prevailed among us for so long. We ought to agree to consider the questiontabula rasa, and to subject plants to a new, impartial, and unprejudiced examination. An inhabitant of the moon, possessed of intellectual faculties like ours, but without any preconceived ideas about the insensibility of plants, would be the philosopher whom we require. Let us imagine such an observer engagedin studying the productions of our earth, and, after having given his attention to the polypes and other insects multiplied by the process of grafting, passing on to the contemplation of vegetables. He would, doubtless, take them at the period of their birth. With this view, he would sow seed of various species, and he would carefully watch their germination. Let us suppose that some of those seeds have been reversed in the sowing, the sprouting part turned downwards, the stem upwards; and the observer has the skill to distinguish one end of the seed from the other, and knows their functions. After some days, he will remark that the seed has grown into this reversed position, that the stem is turned upward, and the sprouting portion downward. He will feel no surprise; he will attribute a circumstance which is so hurtful to the life of the plant, to the mistake he has made in sowing the seed. But, continuing to observe, he will see the sprout and the stem each bending itself in the opposite direction, and trying to attain the right position. This change of direction will strike him as very remarkable, and he will begin to suspect that the organized being which he is studying is endowed with a certain amount of discernment. Too prudent, however, to pronounce upon these early indications, he will suspend his judgment and pursue his investigations. The plants whose germination our physicist has been observing, have been raised in the neighbourhood of a hedge. Thus favoured, and carefully cultivated, they have made great progress in a very short time. The soil which surrounds them at some distance is of two opposite qualities. That on the right of the plants is rich, damp, and spongy; that on the left is dry, hard, and gravelly. Our observer remarks that the roots, after having begun by extending equally on both sides, have changed their direction, and have spread out towards the rich and humid soil; over which they are stretching, and thus threateningto deprive the plants already there of their due share of nourishment. To prevent this inconvenience, he digs a ditch between the plants which he is observing and those they threaten to starve, and now he thinks he has provided against everything. But the plants, which he believes he has governed, disconcert all his precautions by extending their roots downwards, under the ditch, and gaining the other side.
"Surprised at this, he uncovers one of these roots, but without exposing it to heat, and holds a sponge steeped in water towards it. The root turns itself to the sponge, and when he changes its position, the root accommodates itself to each alteration.
"While our philosopher is meditating profoundly upon these facts, other facts equally remarkable present themselves almost simultaneously. He observes that all these plants have leaned away from the hedge, and are bending forward as though to present every portion of their bodies to the beneficent smiles of the sun. He sees that all the leaves are so turned that their upper surface is exposed to the sun, or to the fresh air, and that the lower surface is directed towards the hedge, or the ground. Former experience will have taught him that the upper surface of leaves serves chiefly as a defence for the lower surface, and that the latter is principally destined to pump up the moisture rising from the earth, and provide for the evacuation of what is superfluous. The direction of the leaves which he notices appears quite in harmony with his experiences. He studies this portion of the plant with increased attention.
"He remarks that the leaves of some species seem to follow the movements of the sun, so that in the morning they turn to the east, in the evening to the west. He sees that some leaves close themselves against the sun, others against the dew. He observes an analogous movement in certain flowers.Afterwards, he observes that no matter what the direction of the plants relative to the horizon has been, the direction of the leaves is always that which he has at first noticed, he bethinks him of changing this direction, and of placing the leaves in a position exactly contrary to their natural one. He has already had recourse to similar means in order to assure himself of the instinct of animals, and to ascertain its bearings. With this view he bends perpendicular plants towards the horizon, and keeps them in that position. Thus, the direction of the leaves is absolutely changed; the upper surface, which previously turned to the sun or to the fresh air, now looks towards the earth or the interior of the plant, and the lower surface, which formerly looked towards the earth or the interior of the plant, now turns to the sun, or the fresh air. But very soon all these leaves begin to move, they turn on their stem as on a pivot, and in an hour they will have resumed their former position. Our observer, wishing to assure himself whether leaves and branches when detached and plunged into water will preserve the inclinations which they manifest when upon the plant of which they formed a portion, subjects them to an experiment whose results leave him no doubt of the fact.
"He places wet sponges under the leaves, and he sees the leaves turn towards the sponges and endeavour to adhere to them by their lower surfaces. He also observes that certain plants, which he has shut up in his cabinet and in a cellar, have turned towards the window, or the grating respectively.
"Finally, the phenomena of the Sensitive Plant, its varied movements, the promptitude with which it contracts when touched, form the interesting subject which terminates his researches.
"Thus plentifully supplied with facts which all seem to tend to the support of belief in the sensibility of plants, which side will our philosopher take? Will he surrenderto these proofs? Will he suspend his judgment? I think he will take the first part."[16]
Charles Bonnet believes, in short, that the plant, as well as the animal, is endowed with sensibility.
According to the system which we have developed, the animal is possessed of a soul, which is still very imperfect, and endowed only with faculties corresponding to its needs. But, since the animal, in addition to the sensibility enjoyed by the plant, possesses intelligence also, we must conclude from thence that the plant has not a soul, properly so called, but only the rudiment, the commencement, in other words, thegermof a soul.
We know that the sun has the privilege of giving birth to organic life upon our globe, his rays have power to produce the formation of living tissues, plants or zoophytes, when they fall upon the earth or the waters, and we may draw this conclusion from all that has gone before, that the sun sends down upon the earthanimated germsunder the form of his rays, which emanate from the spiritualized creatures who dwell in the king-star.
Thus our system of nature completes itself; thus, thanks to solar radiation, the two ends of the immense chain of organized beings whose place and part in the vast theatre of the worlds we have attempted to define are united. Life begins in the waters, its first appearance is in plants and zoophytes; for these two classes of living creatures obey the same laws, andappear to have the same origin. The sun, by sending his vivifying rays upon the earth, produces the formation of plants and zoophytes, which are the points of departure of organization. Theanimated germdeposited by the sun in plants and zoophytes grows, passes from the zoophyte to the mollusc, or articulated animal, and then undergoes a further development, by passing from the mollusc or articulated animal to the fish. This germ of a soul thus becomes a rudimentary soul, provided with certain faculties. In the zoophyte and the mollusc it had only sensibility; in the fish, and then in the reptile, and the bird, it has attention and judgment. The faculties are augmented in proportion as the animal mounts higher in the organic scale. Arrived at its summit, the human being, the soul is in possession of all its faculties, and especially of memory, which during the animal stages of the ascent is obscure and uncertain.
To accord sensibility to plants permits us to unite all the creatures of the living creation, and thus to complete our general system of terrestrial nature.
FOOTNOTES:[15]"Histoire des Plantes," Paris, p. 111.[16]"Contemplation de la Nature(Œuvres d'Histoire Naturelle de Charles Bonnet.") Neuchâtel, 1781.
[15]"Histoire des Plantes," Paris, p. 111.
[15]"Histoire des Plantes," Paris, p. 111.
[16]"Contemplation de la Nature(Œuvres d'Histoire Naturelle de Charles Bonnet.") Neuchâtel, 1781.
[16]"Contemplation de la Nature(Œuvres d'Histoire Naturelle de Charles Bonnet.") Neuchâtel, 1781.
DOES MAN EXIST ELSEWHERE THAN ON THE EARTH?—DESCRIPTION OF THE PLANETS.—PLURALITY OF INHABITED WORLDS.
TTHROUGHOUT the preceding chapters we have reasoned as if the earth were the whole universe. Indeed, almost all men believed that such was the case, from the first establishment of society until the last century. Great mathematical knowledge, profound study, and highly perfected optical instruments are requisite to rectify the false ideas, the errors, and the illusions which are the result of a simple view of the earth and the sky. Great efforts of the mind, and a very difficult struggle against the testimony of our senses are necessary to the recognition that the earth moves, and that the sun is motionless. In order to distinguish the place and the office of each of those softly beaming globes, in the midst of the uniformity of aspect presented by the stars which shine during the night, patient and severe observations, transmitted and repeated from age are indispensable, and, in addition, an excellent scientific method. Let us therefore not be surprised that men have taken so much time to comprehend the ordering ofthe universe, and that they had only the most childish conception of them for thousands of years. The ancients, the Greeks, the Romans, the Egyptians, knew nothing of the universe, except the earth (nor did the Orientals, with the exception of some truly learned men, who had divined the general mechanism of the universe by methods unknown to us, but they concealed their knowledge from the profane). These ancients could speak of only a small portion of the globe: of Europe, Asia, and the North of Africa. The remainder was a dead letter for the peoples of antiquity. After them, and following their example, the first Christians reduced the universe to what they knew of it; they believed there was but one world, because they saw only one. The earth was for them the universe. In the stars they saw only brilliant spots, like silver nails in the celestial vault, to enhance the azure, and charm the eyes of men in the quiet of the night. The moon was the natural beacon of the earth. In the sky there was a shining track followed by the sun, and the torch of day was no larger than the beacon of night. The celestial region which spread itself above the sun and the moon was the Empyrean of the ancients, the Paradise of the Christians and the Mussulmans. It was at once the sojourn of clouds and of light, the habitation of the elect of God, of the saints and the just. Under the earth, and in its interior, were immense abysses, gulfs, and cavities, the dark dwellings of the damned.
This simple cosmogony, which merely translates what our eyes show us, has been that believed by every people in their infancy. Among the savage tribes of the two worlds, inAmerica and in Africa, as in the ancient East, among the Romans as among the Egyptians and the ancient Greeks, this coarse simplicity and absolute ignorance of the constitution of the world prevailed. On this profoundly false basis all the ancient religions were founded. The social customs of modern peoples are based upon the same errors. Language has consecrated them; the earth is everywhere called theworld, as the ancients called it (mundus, κόσμος); every one says the suntravels, orgoes, from east to west, and that the starsriseandset.
Poetry has set its eternal seal on this vicious system, and has, so to speak, consecrated it, by clothing it with all theprestigeof genius and imagination.
Modern astronomy has caused the false skies of antiquity to vanish away; it has dispersed the pretensions of the celestial vault, sown with brilliant spots, and substituted a simple mass of coloured air. It has revealed the true office of each of those stars which we see by day or by night. It has fixed, in an indisputable manner, the real place of the earth in the universe, and, to say the truth, that place is singularly small.
We know now, that the earth, far from being herself the world, is only an imperceptible point of the world. If we only compare it with the sun, we know that our globe is one million three hundred thousand times smaller than the sun. This takes us far away from the idea of the ancient Greeks, who thought they ventured much in asserting that the sun was as big as the Peloponnesus.
In addition, the earth has been dispossessed of all privileges. It was believed formerly to be unique and unrivalled, we now know that there are an infinity of other globes similar to the earth, so that she is no more than one individual in a group of other individuals who resemble her. We know that the earth figures among the planets, that she is only a planet of our system.
What, then, is a planet? the reader will ask. An attentive gaze directed to the stars of night will make him understand it. Let him examine, on any fine evening, the star which is pointed out to him as Mars or Jupiter, and to which a certain position is assigned at a given hour. Then, a few hours later, let him come and look once more for Mars or Jupiter, and he will perceive that the position of Mars or Jupiter, with respect to the other stars, is changed. Or he may do better still. Let him look at Mars or Jupiter through the telescope of an observatory, or the glass of one of those open-air astronomers who are to be found in the public ways in Paris and other great cities. Thus he may see Mars or Jupiter change his place under his own eyes. While the other stars remain motionless, Jupiter or Mars will pass away from the field of the glass.
There are, then, fixed stars and movable stars. The movable stars are the planets (πλανήτης, from πλάνος, wandering). The fixed stars are what wecallstars. It is not difficult to distinguish the planets from the stars with the naked eye. The stars emit sparkling light, whence comes their name, from the Latinstellare, to shine, and their light twinkles. The planets, on the contrary, shine with a steady,mild, unvacillating light. The reason of this difference is, that the light shed by the stars is their own. The stars are so many suns resembling ours. They illumine worlds like our world, so prodigiously distant that we cannot even perceive them. The planets do not shine of themselves; they merely reflect, like gigantic mirrors, the light of the sun which illumines them, and renders them visible to us. Thus, the planets are stars which travel. They revolve around the sun. The earth, being a planet, is a travelling star, which revolves around the sun.
But the earth is not the only planet of our solar system. There are seven others, which do not differ essentially from the earth. The names of the eight planets which compose our solar system, are as follows, arranged according to their distance from the sun: Mercury, Venus, the Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Between Mars and Jupiter there is a collection of small bodies, which seem to be fragments of broken planets; they are called asteroïds. At present, in 1871, more than a hundred are known, and it is not yet fifty years since they were first sought for in the sky. These asteroïds may be collected together in our fancy, and formed into a separate group, which would be a ninth planet. Let us glance at the planets which compose our solar system.
Plates 4 and 5, which accompany these pages, will suffice to give an idea of the relative dimensions of the planets. In these two plates the planets are arranged according to the order of their distance from the sun. In plate 4, Mercury, Venus, the Earth, and Mars are represented; in plate 5, theasteroïds Jupiter, Saturn, Uranus, and Neptune. Mercury is the nearest planet to the sun, his distance from the central orb being only fourteen millions of leagues, which, in astronomy, is near neighbourhood. This planet revolves upon its axis with the same rapidity as the earth. The day, in Mercury, is only three minutes longer than ours (24h. 3ms.). Being closer to the sun than the earth is, Mercury turns more quickly round the sun, so that its year is only 88 days, whereas ours is 365 days.
We know that the sole cause of the inequality of the seasons, as well as of day and night in the planets, is the inclination of the star on its axis of rotation. If the planets, while revolving round the sun, retained the verticality of the axis which joins these north and south poles, there would be perfect equality in the distribution of the solar light and heat over the same latitudes; along each parallel there would be a complete regularity in the lighting and warming of the planet; the differences of heat and cold would not depend on anything but their greater or less distance from the sun. But this verticality only exists for two or three planets of our system. The others, and among them Mercury, Venus, the Earth, and Mars, are strongly inclined on their axis of rotation.
They revolve in a bent position, as if they had received a great blow on the shoulder, which had caused them to deviate from their primitive and regular situation. From this there results a very variable disposition of the duration of the light, and consequently of the heat, which these inclined planets receive from the horizontal rays of the solar star. Thus the inequality in the length of the days and nights, and the diversity of the four seasons on the same parallel, are accounted for.[17]
Mercury. Venus. Earth. Mars.Sun.Fig. 4.—Comparative Size of the Planets Mercury, Venus, the Earth, and Mars.
Mercury. Venus. Earth. Mars.
Sun.
Fig. 4.—Comparative Size of the Planets Mercury, Venus, the Earth, and Mars.
The inclination of the axis of the terrestrial sphere is 23° which is a considerable deviation, and occasions great differences in the duration of days and of seasons on different points of our globe. The inclination of the axis of the planet Mercury is enormous: it is 70°. This planet bends over itself as if about to fall. Hence results prodigious variation of light and heat on the same parallel, and seasons whose abrupt changes must be painful and hard to bear by the inhabitants of this planet, if such inhabitants exist.
Mercury is five times less than the Earth, as is shown in plate 4. Venus comes after Mercury, according to distance from the Sun.
Venus, which is 27,000,000 of leagues from the Sun,receives twice as much light and heat as our globe. Its days are of nearly the same length as ours (23 hours, 21 minutes), but its year, necessarily shorter than that of the Earth, since it is nearer to the Sun, lasts only 224 days. Its seasons last two months each. Its globe is nearly of the same bulk as that of the Earth. Venus is almost always wrapped in clouds, which must fall in rain, forming rivers and seas. These waters refresh the plains, which must be scorched by the heat of the burning sun. The seasons are still shorter and more unequal in Venus than in Mercury; its axis is, in fact, inclined at 75°.
After Venus comes the Earth, which is almost of the same bulk, but 28,000,000 of leagues from the Sun. Its diameter is nearly 3000 leagues. It accomplishes its revolution on its axis in 24 hours (23 hours, 56 minutes, 4 seconds), and in 365 days, 5 hours its revolution around the sun.
The inclination of the Earth's axis is 23°, which produces the differences of days and nights, and the inequality of the seasons, according to latitude. The Earth possesses a privilege denied to the planets Mercury, Venus, and Mars; she has a secondary star, or satellite, called the Moon. Placed at a distance of only 90,000 leagues from the Earth, the Moon accomplishes her revolution around it in 27 days. It is not the object of this work to give any description of our globe. We will suppose our readers to be sufficiently acquainted with it, and pass on to the planet which comes next to it in the scale of distance from the Sun. This is the planet Mars.
An extraordinary resemblance exists between Mars and theEarth. Physical, geographical, and climatological conditions, days and nights, seasons, celestial perspectives, all are alike in these two planets, with the sole difference that the globe of Mars is half as small again as that of the Earth; so that, if a man were transported to Mars, he might believe himself to be, not in a strange planet, but in a little known corner of the Earth, such as Australia or Polynesia.
As we pursue our journey through the heavens, ever increasing our distance from the Sun, we shall find, after Mars, the group of the Asteroïds. We shall not linger before this cluster of small stars, which is no doubt nothing but a collection of the dismembered fragments of a planet, which formerly existed in this particular point of space, and was dashed to pieces by some formidable accident in the universe. These little stars, like the important planets, have each their names, such asVesta,Pallas,Circe, &c., &c.Maximiliana, andFeroniaare placed at the two extremities, with respect to distance from the Sun. These remains of a broken star continue to circulate around the Sun, like the planet which they formerly composed.
After the Asteroïds comes great Jupiter.
Jupiter is the largest planetary sphere in our solar system, being 1400 times greater than the Earth. Its distance from the Sun is 200,000,000 miles. In consequence of this distance, its year is as long as twelve of our years. Notwithstanding itscolossaldimensions, Jupiter turns with such rapidity upon its axis, that it accomplishes an entire revolution in twelve hours, so that its day and night are respectively onlyten hours long. The shortness of Jupiter's nights are compensated by the existence of four moons, or satellites, which revolve around this planet, and give it permanent light. This illumination by reflection, added to very long twilights, must make Jupiter's nights nearly equal to the day in brightness.
Though Jupiter suffers under the disadvantage of very short days, it has on the other hand the inappreciable advantage of perfect equality in the length of its days and nights, and of that of the four seasons over all its parallels. The axis of Jupiter is hardly at all oblique, and therefore Jupiter, like the planet Saturn, enjoys a sort of perpetual spring, that is to say, an equable distribution of solar heat and light along the same degrees of latitude. Jupiter, unlike Mars and Venus, has no vicissitudes of seasons, no sudden and painful transitions from cold to heat in the same place. The climates are invariable in each latitude, and the seasons are hardly discernible.
The globe of Saturn is 734 times larger than that of the Earth, and is 364,000,000 leagues from the Sun. It takes thirty years to perform its revolution around the central star, and its year is therefore thirty times as long as ours.
Saturn, like Jupiter, has very short days. It revolves on its axis in ten hours, so that its day and night respectively are but five hours. But it has eight moons, or satellites, which accompany it, and give it light, thus, as in the case of Jupiter, supplementing the shortness of its days. There is hardly any obliquity of the axis of Saturn, so that its days and nightsare always equal. There is a perpetualequinox, and the climates are invariable, while variation of seasons hardly exists. In Saturn, as in Jupiter, perpetual spring reigns. Saturn has one peculiarity which does not belong to any other body in our solar system. It is placed in the centre of a ring, of the same nature as its own, and which surrounds it on every side. This ring (see plate 5), is surrounded by a second, and the second by a third, and the whole are called the rings of Saturn. This circular envelope is exceedingly thin—only ten leagues in thickness—but very wide; its width is 12,000 leagues. It is not motionless, but it revolves with the globe which it surrounds.
The strange disposition of the rings of Saturn affords a proof of the inexhaustible riches of nature, and the variety of forms which the Creator has called into being in the vast universe. It ought to guard us against our constant tendency to model all the worlds which we do not know, upon the type of the earth.
Hardly anything is known about the peculiarities of Uranus, a planet which is only eighty-two times larger than the earth, but which is 732,000,000 of miles from the sun, and takes eighty-four years to accomplish its revolution around the central star.
Plate 5 shows the relative proportions of Uranus and the earth. The prodigious distance of Uranus from our globe, added to its small size, renders it almost inaccessible to observation.
For the same reason, nothing can be ascertained respectingthe physical and geographical conditions of Neptune, the last planet of our solar system, which was discovered in our time by M. Le Verrier, thanks to the simple force of calculation, thereby affording the most brilliant proof ever given of the utility of the mathematical sciences. Neptune is so small and so far from us, that it is probable mere observation of the heavens would never have detected its existence. In this case mathematical analysis was more powerful than the telescope. It would be impossible to give particulars analogous to those which we have supplied concerning the foregoing planets, in reference to a star only 105 times larger than the earth, which revolves at the distance ofone milliard 150 millions of leaguesfrom the sun, and the duration of whose year is 164 times that of the terrestrial year, so that if the ages of the Christian era were counted according to the Neptunian chronology, instead of being in the 19th century, we should be in the 12th year of that era. All we can say about Neptune, therefore, is that it forms the boundary of the domain of our visible world.
We cannot, however, state positively that our solar world terminates at this limit. No doubt the range of our astronomical glasses goes no farther, but assuredly they do not sweep the boundaries of the empire of the sun. It is known, in fact, that comets return to us after having (as indicated by their geometrical curve), swept over the depths of space to a distance of thirty-twomilliards of leagues. Thus the distance of one milliard 150 millions of leagues, which is that of Neptune from the sun, by no means represents the confines of our solar world, but simply defines the limits of the range of our telescopes.
Asteroids. Jupiter. Saturn.Uranus. Neptune.Size of the earthFig. 5.—Size of the Planets Jupiter, Saturn, Uranus, and Neptune compared with the Earth.
Asteroids. Jupiter. Saturn.Uranus. Neptune.
Fig. 5.—Size of the Planets Jupiter, Saturn, Uranus, and Neptune compared with the Earth.
This rapid glance at our solar system in its entirety, proves that the earth is not in possession of any privilege. The part which she plays in the economy of the universe is equally fulfilled by other stars, and there is nothing to justify the pre-eminence assigned to her by the ancients. She is not the largest, the warmest, or the brightest of the planets. She simply forms a portion of a group of stars, and is but one individual of that group.
These considerations tend to lead us to a very important deduction. Since the earth is in no way distinguished from the other planets of our solar system, there must exist in other planets the things which are found on our globe; air, water, a hard soil, rivers and seas, mountains and valleys. Even vegetation and forests ought to be there, regions covered with verdure and with shade. So there surely ought to exist in the other planets, animals, and even men, or at least creatures superior to animals, corresponding to our human type.
But is this possible? is it true? are the planets which, like the earth, and together with it, turn round the sun, constituted physically as the earth is? Are they covered with vegetable growth? are they tenanted by animals and by beings belonging to the human type?
This grave question has been profoundly discussed by M. Camille Flammarion, in a work entitledPluralité desMondes Habités, and in a later publication,Les Mondes Imaginaires et les Mondes Réels. It would be outside the province of this book to follow the author through the various scientific considerations, from which he reasons that the planets which form a portion of our solar system, are, like the earth, the scene of life, organization, thought, and feeling. In the 17th century, Fontenelle and Huygens had successfully approached this successful problem, which M. Camille Flammarion has lately treated with especial care and development, invoking the lessons of contemporaneous astronomy and physics, which refer to the subject. We therefore refer the reader, who wishes to be instructed upon the question of the possibility of the planets being inhabited, to M. Flammarion's works.
FOOTNOTES:[17]Milton, in hisParadise Lost, says that before the fall of our first parents, perpetual spring reigned upon the Earth, but that as soon as Adam and Eve had eaten the forbidden fruit, angels, with flaming swords, were sent from Heaven to incline the poles of the Earth more than 20 degrees. It is well for us that the angels did not cause them to incline farther, or our seasons would have been still shorter and more defective. Fourier pretends that it would be possible for humanity to produce an effect sufficiently great to set the globe straight upon its axis, and thus restore the equality of the seasons, and perpetual spring. This philosopher forgot to indicate one thing only, the mechanical means by which man is to produce this effect. This theory reminds us of the drowning man who fancied he could save himself by catching hold of his own hair, while he was struggling in the water.
[17]Milton, in hisParadise Lost, says that before the fall of our first parents, perpetual spring reigned upon the Earth, but that as soon as Adam and Eve had eaten the forbidden fruit, angels, with flaming swords, were sent from Heaven to incline the poles of the Earth more than 20 degrees. It is well for us that the angels did not cause them to incline farther, or our seasons would have been still shorter and more defective. Fourier pretends that it would be possible for humanity to produce an effect sufficiently great to set the globe straight upon its axis, and thus restore the equality of the seasons, and perpetual spring. This philosopher forgot to indicate one thing only, the mechanical means by which man is to produce this effect. This theory reminds us of the drowning man who fancied he could save himself by catching hold of his own hair, while he was struggling in the water.
[17]Milton, in hisParadise Lost, says that before the fall of our first parents, perpetual spring reigned upon the Earth, but that as soon as Adam and Eve had eaten the forbidden fruit, angels, with flaming swords, were sent from Heaven to incline the poles of the Earth more than 20 degrees. It is well for us that the angels did not cause them to incline farther, or our seasons would have been still shorter and more defective. Fourier pretends that it would be possible for humanity to produce an effect sufficiently great to set the globe straight upon its axis, and thus restore the equality of the seasons, and perpetual spring. This philosopher forgot to indicate one thing only, the mechanical means by which man is to produce this effect. This theory reminds us of the drowning man who fancied he could save himself by catching hold of his own hair, while he was struggling in the water.
THAT WHICH HAS TAKEN PLACE UPON THE EARTH WITH REGARD TO THE CREATION OF ORGANIZED BEINGS HAS PROBABLY ALSO TAKEN PLACE IN THE OTHER PLANETS.—THE SUCCESSIVE ORDER OF THE APPEARANCE OF LIVING BEINGS ON OUR GLOBE.—THIS SAME SUCCESSION HAS PROBABLY TAKEN PLACE IN EACH OF THE PLANETS.—PLANETARY MAN.—THE PLANETARY, LIKE THE TERRESTRIAL MAN, IS TRANSFORMED, AFTER DEATH, INTO A SUPERHUMAN BEING, AND PASSES INTO THE ETHER.
WWE believe, with M. Camille Flammarion, that organized beings exist in all the planets. But are these beings who live in the distant worlds accompanied, like terrestrial man, by a superior type? This is the subject which we now propose to examine. In the absence of observation analogy is our only means of investigation, and, guided by analogy, we must admit that the processes which have taken place upon the earth, since the epoch of its formation, must have similarly taken place upon all the other planets, the earth's congeners.
We are now perfectly acquainted with the manner in which the vegetable and animal creations have appeared, and succeeded each other upon our globe since its origin. At firstthe earth was simply a collection of gas, and burning vapour which revolved round the sun. This mass of gas and vapour grew cold by degrees in its passage through space, and first becoming liquid, afterwards assumed the consistency of paste, and ultimately became solid, by a gradual process of refrigeration. Consolidation began on the surface, because the circumference of a sphere is more exposed than the remainder of the mass to refrigerating influences. Then the water and the vapours which still flowed upon the consolidated globe became condensed, and, falling in burning showers upon the hard soil, they formed the first seas.
The proof that the earth's primitive condition was like to a liquid or half paste, is, that if we take a plastic sphere, for instance a slightly fluid ball of quicksilver, and make it turn rapidly upon its axis, we observe that it swells out in the middle, and becomes flat at the two poles, or the extremities of the axis; this is the effect of the centrifugal force engendered by the rotatory motion. Now the earth is depressed at the poles, and slightly swelled out at the equator.
The other planets must have been formed by the same process as the earth. They were, no doubt, composed of a collection of gas and vapours, which became liquid, pasty, and eventually solid, by a process of refrigeration. This process, taking effect especially upon their surface, they began to put forth a skin, or exterior and solid covering, which was the soil of the planet. On this resisting soil fell the liquids resulting from the condensation of the water vapour, and thus the first seas of the planets were formed.
We would remind those who doubt the correctness of this theory that the poles of the globe of Saturn and that of Jupiter are much more flat than those of the Earth; which is explained by the greater velocity of the rotation of each upon its axis. Our days are 24 hours long, whereas those of Jupiter and Saturn are only 10 hours. Greater rapidity of rotation produces a correspondingly increased depression at the extremities of the axis. This geometrical result demonstrates the justice of the assimilation in their respective origin which we maintain between the Earth and the other planets.
In the warm waters of the basin of the seas the first living beings which existed upon our globe appeared. Animal life commenced in the waters, in the primitive forms of zoophytes and mollusca, as we know, because zoophytes and mollusca, with the addition of a few articulates, composed the animal remains found in the transition strata which come after the primary formations. The first vegetables are found in the same transition strata, they are mosses, algæ, and ferns.
When the earth had become somewhat cooler, phanerogamous vegetables appeared upon the continents. Numerous vegetable species were simultaneously created, for the flora of the secondary formations is extremely rich and varied.
It was the same in the case of animals. So the zoophytes, mollusca, and fish which existed in the transition period succeeded reptiles, in the secondary formation, which inhabited both land and sea. At this period appeared those monstrous saurian reptiles, whose formidable shapes, and colossal dimensions fill us with surprise and almost with dismay. Thenthe giganticmosasaurusravaged the seas, the terrible ichthyosaurus spread terror among the inhabitants of the waters, and the gigantic iguanodon laid waste the forests. The secondary formation, which is filled with their remains, shows us that at that period reptiles held the first rank in creation.
At a later date, the atmosphere having become purer, birds began to traverse the air. In the tertiary deposit we find the remains of several kinds of birds, and these remains, which do not exist in the earlier formations, sufficiently prove that it was in the tertiary period that birds made their first appearance upon the terrestrial globe.
Still later, at a more advanced period of the tertiary epoch, mammifers appear upon the scene. We must observe that these animal species do not replace each other, that the one does not exclude the other. Several of the ancient animal species continue to exist after the appearance of entirely novel kinds. We might quote as instances whole groups of animals, such as the lingulæ (mollusca), the coral (zoophyte) among animals, and among vegetables, the algæ, ferns, and lycopodes, which appeared on our globe in the earliest period of the reign of organization, and have never ceased to exist. It was not until the last epoch in the history of the Earth, during the quaternary epoch, that man appeared, the highest product of living creation, the ultimate term of organic, intellectual, and moral progress, the crowning upon our earth of the visible edifice of nature.
At present, man lives together with the animals which began to exist during the quaternary epoch, and a great number of other kinds of mammifers which were created during the tertiary epoch.
The various phases of the development of the animal and vegetable kingdoms on our globe, these perfected organized species each succeeding the other, and finally reaching the superior type which we call man, must, in our opinion, have been produced in the selfsame order, upon the other planets of our solar world. M. Flammarion proves, in the work which we have already quoted, that the physical and climatological constitution of the planets is similar to that of our globe. There is therefore no reason why things should have taken place otherwise in Mercury, Jupiter, or Venus, than in the Earth, in respect to the successive order of the creation and appearance of living beings, and, in our belief a precisely similar successive appearance of vegetables and animals, has taken place in these planets. The plants and animals of Mercury, Jupiter, Saturn, &c., were certainly not identical with those species which have had existence on the Earth, and perhaps no resemblance could be traced between them, but all, in their successive appearance, obeyed the principle of progress and perfecting. Life, commencing in the burning waves of the primitive seas, subsequently manifested itself upon the continents. Animals of aërial organization have lived upon these continents, their species have by degrees reached the perfection of their type, at length, and finally, a creature appeared in these planets more complete, superior in organization, intelligence, and sensibility to all the animalcreation which formed the population of each particular globe.
This superior being, this last step of the ascending scale of living creation proper to the planetary worlds, the corresponding analogous creature to terrestrial man, we shall take leave to callplanetary man.
In all the planets, then, there existmen, as on the earth, just as there exist animals which are inferior to that noble and privileged type.
According to the views which we have explained at the commencement of this work, terrestrial man undergoes, after his death, a glorious metamorphosis. Leaving his miserable material covering here below, his soul springs upward into space, and becomes incarnate in a new being, whose type is infinitely superior, by reason of its moral perfection, to that of our poor humanity. He becomes that which we have called thesuperhuman being. If this be true of the terrestrial man, it must be equally true of the planetary man. So that the superhuman being must proceed, not only from the earth, but from all the other planets.
Superhuman beings come from the human souls who have lived either upon the Earth, or upon Mercury, Jupiter, Venus, Saturn, &c. And precisely as the superhuman being, who comes from the Earth passes into the surrounding ether, so the planetary man, leaving Mars, Mercury, Jupiter, &c., passes into the ether, which surrounds his own planet, becomes incarnate in a superhuman being, and lives in the ethereal plains adjoining the planet which he has quitted.
All these superhuman beings float in the clouds of ether which, in the case of every planet, succeed to its atmosphere.
Thus, the principles upon which we have based terrestrial humanity, are general, and apply to all planetary humanity. Not from the Earth only do those souls proceed who are incarnate in new creatures in the bosom of the ethereal spaces, these souls proceed from all the globes which, together with the Earth, form the attendant court of the royal Sun.