[AE]Harvey on Generation, page 257.
[AE]Harvey on Generation, page 257.
The matrix, as we have already said, takes a very ready growth after conception, and it continues also to increase in proportion with the fœtus; but the fœtus at length outgrows the matrix, and then, especially when it approaches maturity, it may be too much confined, and agitate the matrix by reiterated motions and violent efforts. The mother sensibly feels the impression of these painful sensations, and which are called periodic pains after the labour commences. The more power the fœtus exerts to dilate the matrix the greater it finds the resistance, from the natural compression of the parts. From thence all the effect falls on the orifice, which has been increasing by degrees during the latter months of pregnancy. The head of the fœtus, forcibly inclining against the sides of the orifice, dilates it, by a continual pressure, till the moment of delivery, when it opens sufficiently for the child to escape from the womb.
What makes it probable that the labour-pains proceed only from the dilatation of theorifice of the matrix is, that this dilatation is the only means to discover whether the pains felt are in fact the pains of labour, for women often feel very sensible pains, which are not those that immediately precede delivery. To distinguish the false from true pains, it has been recommended for the midwife to touch the orifice of the matrix, as if the pains be true the dilatation will always increase, and if they are false pains, that is to say, pains which proceed from some other cause than that of the approaching delivery, the orifice will contract rather than dilate, or at least will not continue to dilate. From hence we have sufficient foundation to imagine, that these pains proceed from a forced dilatation of the orifice. The only thing which embarrasses on this occasion is that alternative of rest and sufferings the mother endures. This circumstance of the effect does not perfectly agree with the cause which we have just indicated; for the dilatation of an orifice, which is made by degrees, should produce a constant and continued pain, without any intervals of ease. But possibly the whole may be attributed to the separation of the placenta, which we know is fastened to the matrix by a number of papillæ, which penetrateinto the vacuities or cavities of this viscera; therefore may it not be supposed that they do not separate from their cavities all at the same time; that each separation causes those acute pains, and the intervals between are those of ease and rest? The effect in this case perfectly answers the cause, and we can support this conjecture by another observation.—Immediately before delivery there issues a whitish and viscous liquor, like that which flows from the nipples of the placenta when drawn out of their places, which makes it probable that this liquor, which then issues from the matrix, is produced by the separation of some of the papillæ of the placenta.
It often happens that the fœtus quits the matrix without bursting the membranes, and consequently without the contained liquor flowing out. This kind of delivery appears to be most natural, and resembles that of most animals; nevertheless, the human fœtus commonly pierces its membranes by the resistance it meets with at the orifice of the matrix. It also sometimes brings away part of the amnios, and even the chorion, upon its head like a cap. When these membranes are pierced or torn, the liquors, called thewaters, which they containflow out, and the sides of the orifice of the matrix, and the vagina, being thus moistened, give way more easily to the passage of the child. After the flowing of this liquor there remains sufficient room in the matrix for the midwife to return the child, if the position is unfavourable. When the fœtus is come out the delivery is not entirely completed, the placenta and membranes remain in the matrix, and the new-born infant adheres to them by the umbilical cord; the hand of the midwife, or the weight of the body of the infant alone, draws them out by means of this cord. Those organs which were necessary to the life of the fœtus become useless, and even noxious to the new-born infant. They are instantly separated from the body of the child, by tying the umbilical cord about an inch distance from the navel, and by cutting it about an inch from the ligature. The remainder of this cord dries away, and separates of itself from the navel, about the sixth or seventh day.
On examining the fœtus previous to its birth we may form some idea of its natural functions. It has organs, which are necessary to it while in the womb of its mother, but which become useless. For the better understandingthe mechanism of these functions, we must explain a little more particularly the nature of those necessary parts, the umbilical cord, the membranes, the liquor which they contain and the placenta. The umbilical cord, which is attached to the body of the fœtus at the navel, is composed of two arteries and one vein; these prolong the circulation of the blood, but the vein is larger than the arteries. At the extremity of the cord each of these vessels divide into an infinity of ramifications, which extend between two membranes. They separate at equal distances from the common trunk; so that these ramifications are round and flat, and are called, when thus collected, theplacenta. The external surface, which is applied against the matrix, is convex; the internal concave. The blood of the fœtus circulates in the cord, and in the placenta. The arteries of the cord spring from two large arteries of the fœtus, and carry the blood through the arterial ramifications of the placenta; from thence it passes into the venous branches which carry it into the umbilical vessels; these communicate with a vein of the fœtus, in which vessels it is received.
The concave surface of the placenta is clothed by the chorion; the convex is also covered by a kind of soft membrane, easily torn, which seems to be a continuation of the chorion, and the fœtus is included under the double coat of the chorion and the amnios. The form is globular, because the intervals between the membranes and the fœtus are filled with a transparent liquor. This liquor is contained by the amnios, which is the internal membrane, it is thin and transparent; it folds round the umbilical cord at its insertion into the placenta, and covers it the whole length to the navel of the fœtus. The chorion is the external membrane; it is thick and spongy, sprinkled with sanguinary vessels, and composed of many coats, the exterior of which covers the convex surface of the placenta. It follows the inequalities, and covers the papillæ, which spring from the placenta, and are received in the cavities found at the bottom of the matrix, calledlacunæ. The fœtus adheres to the matrix by these insertions.
Some anatomists have thought that the human form had, like those of certain quadrupeds; a membrane calledallantois, destinedto receive the urine; and they have pretended to have found it between the chorion and the amnios, or in the middle of the placenta at the root of the umbilical cord, under the form of a very large bladder, in which the urine entered by a long pipe that composed part of the chord, and which opened on one side into the bladder, and on the other in this allantois membrane, being similar to the urachus in other animals. They owned, however, that it was not near so large in the human fœtus as in quadrupeds, but that it was divided into many tubes, so minute, that they could scarcely be perceived, and that the urine passed into their cavities.
The experience and observations of most anatomists are contrary to this supposed discovery. They admit there is a kind of ligament which adheres by one end to the external surface of the bottom of the bladder, and extends to the navel; but it becomes so delicate, on entering into the cord, as to be nearly reduced to nothing: in common this ligament is not hollow, and we can see no orifice at the bottom of the bladder.
The fœtus has no communication with the open air, and the experiments made upon thelungs prove they have never respired; for they sink to the bottom when put in water: whereas those of infants who have breathed always float on the top; the fœtus then does not respire in the womb, consequently it cannot form any sound by its voice; and therefore what has been related of the groaning and crying of children before their birth may be considered as fables. After the flowing of the waters it may happen, that the air has found an entrance into the cavity of the matrix, and then the infant may begin to respire before it is brought forth. In this case it may be able to cry, as the chicken cries before the shell of the egg is broken, which it can do from there being air in the cavity which is between the external membrane and the shell. This air is found in all eggs, and is produced by the internal fermentation of matters contained in them[AF].
[AF]See La Statique des Vegetaux, Chap. vi.
[AF]See La Statique des Vegetaux, Chap. vi.
The lungs of the fœtus being without any motion, have no more blood enter into them than is requisite to nourish and make them grow; and there is another road opened for the course of its circulation. The blood in the right auricle of the heart, instead of passinginto the pulmonary artery, and returning, after having ran through the lungs into the left auricle by the pulmonary vein, passes immediately into the left by an opening, called theforamen ovale, which is in the partition of the heart between the two auricles. It enters afterwards into the aorta, which distributes it by its ramifications, at going out of which the venous branches receive it, and bring it back to the heart by uniting all in thevena cava, which terminates at the right auricle of the heart. The blood which this auricle contains, instead of passing entirely by the foramen ovale, may escape in part into the pulmonary and the aorta by an arterial canal, which goes immediately from the one to the other. It is by these roads that the blood of the fœtus circulates without entering into the lungs, as it enters into those of children, adults, and every animal which breathes.
It has been thought that the blood of the mother passes into the body of the fœtus, by means of the placenta and umbilical cord. It was supposed that the sanguinary vessels of the matrix opened into the vacuities, and those of the placenta into the nipples, and that they joined one to the other; but experience isquite contrary to this opinion; for if the arteries of the umbilical cord is injected the liquor returns by the veins, and not any part of it escapes externally. Besides, the nipples may be drawn from the vacuities where they are lodged, without any blood issuing either from the matrix or placenta: a milky liquor only issues from both, and which, we have already observed, serves the fœtus for nutriment. This liquor possibly enters into the veins of the placenta, as the chyle enters into the subclavian vein; and perhaps the placenta in a great measure performs the office of the lungs in bringing the blood to maturity. It is certain that the blood appears much sooner in the placenta than in the fœtus, and I have often observed in eggs that have been under the hen for a day or two, that the blood appeared at first in the membranes, and that their sanguinary vessels are very large and numerous, while the whole body of the chicken, excepting the point where these blood-vessels terminate, is only a white and almost transparent matter, in which there is not the smallest sign of a sanguinary vessel.
It has been imagined, that the liquor of the amnios is a nutriment the fœtus receivesby its mouth. Some naturalists pretend to have observed this liquor in the stomach, and to have seen some fœtuses to which the umbilical cord was entirely wanting, and others who had but a very small portion, which did not at, all adhere to the placenta; but in this case might not the liquor have entered into the body of the fœtus by the small portion of the umbilical cord, or by the umbilical vessel itself? Besides, to these observations we may oppose others. Some fœtuses have been found whose lips were not separated, and others without any opening in the œsophagus. To conciliate these circumstances, some anatomists have thought that the aliments passed into the fœtus partly by the umbilical cord, and partly by the mouth: none of these opinions appear to have any foundation. It is not the question to examine the growth of the fœtus alone, and to seek from whence and by what it draws its nutriment, but how the growth of the whole is made; for the placenta, liquor, and membrane increase in size as well as in the fœtus; and consequently the instruments and canals employed to receive or carry this nutriment to the fœtus, have a kind of life themselves. The expansion of the placenta and membranesis as difficult to conceive as that of the fœtus; and we might say, with equal propriety, that the fœtus nourishes the placenta, as that the placenta nourishes the fœtus. The whole mass is floating in the matrix, and without any adherence at the commencement of this growth: therefore the nourishment can be only made by an absorption of the milky matter contained in the matrix. The placenta appears first to draw this nutriment, to convert this milk into blood, and to carry it to the fœtus by veins. The liquor of the amnios appears to be only this milky liquor depurated, the quantity of which increases by a like absorption, proportionate to the increase of the membranes, and the fœtus probably absorbs the liquor, which appears to be the necessary nutriment for its expansion. For we must observe, that for the first two or three months the fœtus contains very little blood; it is as white as ivory, and appears to be composed of lymph which has taken some solidity; and as the skin is transparent, and all the parts very soft, we may easily conceive that the liquor in which the fœtus swims may penetrate them, and thus furnish the necessary matter for its nutrition and expansion. It may be supposedthat the fœtus in the latter stages takes its nutriment by the mouth, since in the stomach we find a liquor similar to that in the amnios, urine in the bladder, and excrements in the intestines; and as we find neither urine normeconiumin the amnios, there is reason to conclude that the fœtus does not void its excrements, especially as some are born without having the anus pierced, although they had a great quantity ofmeconiumin the intestines.
Although the fœtus does not immediately adhere to the matrix, but is only attached to it by small external nipples, though it has no communication with the blood of its mother, but is as independant of her who bears it, in many respects, as the egg is of the hen that hatches it, yet it has been pretended, that all which affects the mother affects the fœtus; that the impressions of the one act on the brain of the other; and to this imaginary influence resemblances, monsters, and especially marks on the skin of some children, have been attributed. I have examined many of these marks, and they all appear to me to have been caused by a derangement in the texture of the skin. Every mark must have a figure which will resemble something or other; but I am certain the resemblancesso formed depend rather on the imagination of those who see them than on that of the mother. On this subject the marvellous has been carried as far as it could go. It has not been only said that the fœtus carried real representations of the longings of its mother, but that, by a singular sympathy, the marks, which represent strawberries, cherries, &c. change their colour, and become deeper in the season of those fruits. With a little more consideration, and less prejudice, this colour may be seen to change much oftener, and that it must happen every time the motion of the blood is accelerated, whether by the heat of summer or from any other cause. These marks are either yellow, red, or black, because the blood gives these tints to the skin when it enters in too great quantities into the vessels. If these marks have the longings of the mother for their cause, why have they not the forms and colours as varied as the objects of her desires? What a curious assemblage of figures would be seen if all the whimsical desires of the mother were written on the skin of the child?
As our sensations have no resemblance to the objects which cause them, it is impossible thatdesire, fear, horror, or any passion, or internal emotion, can produce real representations of those objects; and the child being in this respect as independant of the mother as the egg is of the hen, I should as soon believe that a hen, which saw the neck of a cock twisted, would hatch chickens with wry necks, as that, by the power of imagination, a woman, who happened to see a man broke upon the wheel, would bring forth a child with its limbs broken in the same manner.
But even supposing this circumstance attested, I should still support the opinion, that the imagination of the mother had not been the cause, for what is the effect of horror? an internal motion, a convulsion in the body of the mother, which might shake, compress, and agitate the womb. What can result from this commotion? nothing similar to the cause, for if this commotion was very violent the fœtus might be killed, wounded, or deformed in some of its parts; but how is it to be conceived that this commotion can produce any thing resembling the fancy of the mother in the fœtus, unless we believe, with Harvey, that the matrix has the faculty of conceiving ideas, and realizing them on the fœtus?
But, it may be urged, if it was not affected by the imagination of the mother, why did the child come into the world with broken limbs? However rash it may appear to explain a matter which is extraordinary and uncertain, and of which we have no right to exact a solution, yet this question appears to me answerable in a satisfactory manner. Circumstances of the most rare and extraordinary kind happen as necessarily as those which are frequent and common. In the infinite combinations which matter can take, the most extraordinary arrangements must sometimes happen; hence we might venture to wager, that in a million, or a thousand millions of children, there will be one born with two heads, four legs, or with broken limbs; it may, therefore, naturally happen, without the concurrence of the mother's imagination, that a child should be born with broken limbs. This may have happened more than once, and the mother, while pregnant, might have been present at the breaking on the wheel, and therefore the defect of the child's formation has been attributed to what she had seen, and to her impressed imagination. But, independant of this general answer, we may give a more direct explanation. The fœtus,as we have said, has nothing in common with the mother; its functions, organs, blood, &c. are all particular, and belong to itself; the only thing which it derives from its mother is the liquor, or nutritive lymph, which filtrates from the matrix. If this lymph is bad, or envenomed with the venereal virus, the child will be alike disordered; and it may be imagined, that all the diseases which proceed from vitiated humours may be communicated from the mother to the child. We know that the small-pox is communicative, and we have but too many examples of children who are, directly after their birth, the victims of the debauches of their parents. The venereal virus attacks the most solid parts of the bones, and it appears to act with more force towards the middle of the bone, where ossification commences; I conceive, therefore, that the child here spoken of has been attacked by the venereal disorder while in its mother's womb, and from that cause it came into the world with its bones broken through the middle.
Rickets may also produce the same effect. There is a skeleton of a rickety child in the French king's cabinet, whose arms and legs have callosities in the middle of their bones.By the inspection of this skeleton, it appeared evident that the bones had been broken during the time it was in the womb, and that afterwards the bones re-united, and formed these callosities.
But enough of a subject which credulity alone has rendered marvellous. Prejudice, especially that sort which is founded on the marvellous, will always triumph over reason, and we should have but little philosophy if we were astonished at it. We must not therefore ever expect to be able to persuade women, that the marks on their children have no connection with their unsatisfied longings. Yet might it not be asked them, before the birth of the child, of what particular longings they had been disappointed, and consequently what will be the marks their children will bear? I have often asked this question, and have only made persons angry without having ever convinced them.
The time that a woman goes with child is generally about nine months; but it is however sometimes longer and sometimes shorter. Many children are born at seven or eight months, and some not till after the ninth; but in general the deliveries which precede the term of ninemonths are more frequent than the others. The common time of a natural delivery extends to twenty days, that is, from eight months fourteen days to nine months and four hours.
Many children are born before the 260th day, and although these deliveries precede the general term, they are not abortions, because these children mostly live. It is commonly thought that children born at eight months cannot live, or at least that many more of them die than those born at seven months. This opinion appears to be a paradox; and by consulting experience I think we shall find it an error. The child brought forth at eight months is more formed, and consequently more vigorous, and likely to live than that which is born at the seventh. Nevertheless this opinion is pretty generally received, and founded on the authority of Aristotle.
The beginning of the seventh month is the earliest term for delivery; if the fœtus is brought forth sooner it dies, and is termed an abortion. There are, however, great limits for the time of human delivery, since they extend from the seventh to the tenth, and perhaps to the eleventh month.
Women who have had many children assert, that girls remain longer in the womb than boys. If this is really the case, we must not be surprized at female children being born at ten months. When children come before nine months they are not so well proportioned as those who are not brought into the world till ten months, the bodies of the latter are sensibly larger and better formed; their hair is longer, the growth of the teeth, although still hid under the gums, is more advanced; the voice is clearer, and the tone more deep.
There is much uncertainty on the occasional causes of delivery, and we do not perfectly know what obliges the infant to quit the womb. Some imagine, that the fœtus having acquired a certain size, the matrix is too confined for its longer stay, and that the constraint felt by the fœtus, obliges it to use every effort to quit its prison; others say, and it is nearly to the same purport, that the weight of the fœtus becomes so great, that the matrix is forced to open to free itself from the burthen. These reasons do not appear satisfactory; for the matrix must always have capacity and strength to contain and sustain the weight of a fœtus of nine months, since it often contains two, and it is certain that theweight and size of the twins of eight months are more considerable than the weight and size of a single child of nine. Besides, it often happens that a child born at nine months is smaller than the fœtus of eight months, although it continues in the womb.
Galen pretends, that the child remains in the matrix till it is able to receive its food by the mouth, and that it only forces its escape from the need of nutriment. Others have said, that the fœtus always receives its nourishment by the mouth from the liquor of the amnios; but which becomes at length so contaminated, by the transpiration and urine of the fœtus, that it becomes disgustful, and obliges the fœtus to use every exertion to quit its confinement. These reasons do not appear better than the first; for it would from thence follow, that the weakest and smallest fœtuses would remain longer in the womb than the strongest and largest, which never happens; besides, it is not food that the fœtus seeks immediately after it is born, for it can stay some time without it; on the contrary, it seems most desirous to disembarrass itself from the nutriment it took when in the womb of its mother, and to return the meconium. Other anatomists have supposed thatthe excrement accumulated in the bowels of the fœtus, gives it great pain, and causes it to make such efforts, that the matrix is at length obliged to give way, and to open a passage for its escape. I acknowledge I am not better satisfied with this explanation than the rest; because, why cannot the fœtus void its excrements in the amnios, if it was pressed so to do? Now this never happens; it appears, on the contrary, that this necessity of voiding the meconium is not felt till after the birth, when the motion of the diaphragm, occasioned by that of the lungs, compresses the intestines and causes this evacuation; for the meconium has never been found in the amnios of a fœtus of ten months who had not respired, whereas a fœtus of six or seven months voids this meconium a short time after respiration.
Other anatomists, and among them Fabricius de Aquapendente, have supposed the fœtus quitted the matrix through the need of procuring refreshment by means of respiration. This cause appears to me still more remote than all the rest, because the fœtus can have no idea of respiration without having respired.
After having weighed all these explanations, I suppose the fœtus's quitting the matrix dependson a quite different cause. The flowing of the menstrua is periodical, and at determined intervals; and although conception suppresses its appearance, it does not destroy the cause; for notwithstanding the blood does not appear at the accustomed times, yet a kind of revolution takes place, like that which is made before conception. Thus it is, there are many women whose menstrua are not suppressed in the first two or three months. I imagine, therefore, that when a woman has conceived, the periodical revolution is made as regular as before; but as the matrix is swelled, the excretory canals cannot give issue to the blood, at least unless it arrives there with such force, and in such quantities, as to open a passage in spite of the resistance, that is opposed to it. In this case blood will appear, and if it flows in a great quantity abortion will ensue, and the matrix take the form it had before. But if the blood only forces one part of these canals, the business of generation will not be destroyed, although the blood appears, because the greatest part of the matrix still remains in the state which is necessary for that purpose.
When no blood appears, as is generally the case, the first periodical revolution is remarkableand felt by the same pains and symptoms. From the first suppression of the menses, therefore, a violent action on the matrix is made, and provided the action is augmented, it destroys the product of generation. It may from thence be concluded, that every conception which is made just before the useful return of the menses seldom succeeds, and that the action of that blood easily destroys the weak roots of a germ so tender and so delicate. The conceptions, on the contrary, which are made just after the periodical evacuations succeed the best, because the produce of the conception has more time to grow, strengthen, and resist the action of the blood, by the time the next revolution happens.
The fœtus having undergone this first trial, and having resisted it, receives more strength and growth, and is more in a condition to contend against the succeeding revolutions. Miscarriages may and do happen in all the periodical revolutions; but they are less frequent in the fourth and fifth months, than either at the beginning or near the end. We have assigned the reasons why they are more frequent at the beginning; it therefore only remains to explain why they are also more frequent towards the end.
The fœtus generally comes into the world during the tenth revolution. When it is born at the eighth or ninth it lives, and these deliveries are not looked upon as miscarriages, because the child, although not so perfectly formed, is still sufficiently so for the purpose of life. It has been pretended, that examples have been seen of children born at the seventh and even at the sixth revolution, that is, at five or six months, which have lived. There is, therefore, no difference between a birth and a miscarriage but what is relative to the living powers of the infant. In general the number of miscarriages in the first, second, and third months are very considerable for the reasons we have given ; and the number of deliveries of the seventh and eighth months are also very great, in comparison with the miscarriages of the fourth, fifth, and sixth months, because in this middle period the product of generation has received more solidity and strength, and having resisted the action of the four first periodical revolutions, a more violent force than the preceding is required to destroy it. The same reason subsists, with additional force, for the fifth and sixth months. But the fœtus, which till then is weak, and can act only by its ownfeeble strength, begins to get strong, and move with vigour; and at the eighth revolution the fœtus, uniting its efforts with those of the matrix, facilitates its exclusion, and it may come into the world in the seventh month, and be capable of living, especially if it happens, as is sometimes the case, to have more than ordinary strength for that period. But if it comes into the world only through the weakness of the matrix, which could not resist the action of the blood in this eighth revolution, the delivery would be regarded as a miscarriage, and the child would not live. But these cases are very rare, for if the fœtus has resisted the seven first revolutions, only particular accidents can prevent it from resisting the eighth. The fœtus, which has acquired this same degree of strength and vigour only a little later, will come into the world at the ninth revolution; and those which require nine months to obtain this same strength, will come at the tenth revolution, which is the most common and general term; but when the fœtus has not acquired in nine months this degree of perfection, it may remain in the womb till the eleventh, and even till the twelfth revolution; that is, till the tenth or eleventh month, as we have many examples.
This opinion, that it is the menstrua which is the occasional cause of delivery at different times, may be confirmed by many other reasons. The females of every animal which have no menses, bring forth at nearly the same terms, and there is but a very slight variation in the duration of their gestation. We may, therefore, suppose that this variation, which is so great in women, comes from the action of the menstrual blood, which is constantly exerted at every periodic return.
We have observed, that the placenta adheres to the papillæ, or the matrix, only by nipples; that there is no blood either in these nipples or in the vacuities they are niched into, and that when they are separated (which is easily done) a milky liquor only issues from them. Now, how happens it that delivery is always accompanied with a considerable hæmorrhage, at first of pure blood, and afterwards mixed with a watery liquor? This blood does not proceed from the separation of the placenta, as the nipples are drawn out without any effusion of blood. Delivery, which entirely consists, of this separation, should not, therefore, produce any blood. Is it not then more accordant with reason to suppose, that it is the action ofthe blood which causes delivery, and that it is this menstrual blood which forces the vessels as soon as the matrix is emptied, and which begins to flow immediately after delivery as it did before conception?
It is known, that in the first months of pregnancy that which contains the seed of generation is not adherent to the matrix. By the experiments of De Graaf it has been seen, that by blowing on the little ball we can make it move. The adhesion to the matrix is never very strong, and at first the placenta with difficulty adheres to the internal membrane of the viscera, and those parts are only contiguous, or joined by a mucilaginous matter, which has scarcely any adhesion. Why then does it occur, that in miscarriages of the first and second month this ball never escapes without a great effusion of blood? It is certainly not caused by the passage of the ball quitting the matrix, since it does not adhere to it; but it is, on the contrary, by the action of this blood that the ball is driven out. Must we not then conclude this blood to be menstrual, which by forcing the canals, through which it had been accustomed to pass before impregnation,destroys the product of conception by retaking its common road?
It appears, therefore, that the periodical revolution of the menstrual blood has great influence on delivery, and that it is the cause why the times of delivery in women vary so much more than in every other female who is not subject to the periodical evacuation, and which always bring forth at the same times. It also appears that this revolution, occasioned by the action of the menstrual blood, is not the sole cause of birth, but that the action of the fœtus itself contributes towards it, since there are instances of a child escaping from the womb after the death of the mother, which necessarily supposes an action proper and particular in itself.
The space of time which cows, sheep, and other animals go with young is always the same, and their deliveries are not attended with an hæmorrhage. May we not then conclude, that the blood voided by women after delivery is the menstrual blood, and that the human fœtus being born at such different terms, can only be by the actions of this blood on the matrix during every periodical revolution? Itis natural to imagine, that if the females of viviparous animals had menses like women, their deliveries would be followed with an effusion of blood, and happen at different terms. The fœtuses of animals come into the world clothed with their membranes (and it seldom happens that the membranes are broken), and the waters flow before the delivery; whereas it is very rare a child is brought forth with its membranes entire. This seems to prove that the human fœtus makes more efforts than other animals to quit its prison; or that the matrix of a woman does not so naturally incline to the passage of the child, for it is the fœtus which tears its membranes, by the efforts it makes against the resistance it meets with at the orifice of the viscera.
RECAPITULATION.
All animals procure nutriment from vegetables, or other animals which feed upon vegetables; there is, therefore, one common matter to both, which serves for the nutritionand expansion bf every thing which lives or vegetates. This matter cannot perform them but by assimilating itself to each part of the animal or vegetable, and by intimately penetrating the texture and form of these parts, which I have called theinternal mould. When this nutritive matter is more abundant than is necessary to nourish and expand the animal or vegetable, it is sent back from every part of the body, and deposited in one or more reservoirs, in the form of a liquor; this liquor contains all the molecules analogous to all parts of the body; and consequently all that is necessary for the reproduction of a young being, perfectly resembling the first. Commonly this nutritive matter does not become superabundant, in most kinds of animals, till they have acquired the greatest part of their growth; and it is for this reason that animals are not in a state of engendering before that time.
When this nutritive and productive matter, which is universally spread abroad, has passed through the internal mould of an animal or vegetable, and has found a proper matrix, it produces an animal or vegetable, of the same kind; but when it does not meet with a proper matrix, it produces organized beings differentfrom animals and vegetables, as the moving and vegetating bodies seen in the seminal liquor of animals, in the infusion of the germ of plants, &c.
This productive matter is composed of organic particles, always active, the motion and action of which are fixed by the inanimate parts of matter in general, and particularly by oily and saline bodies, but as soon as they are disengaged from this foreign matter, they retake their action, and produce different kinds of vegetations and other animated, beings.
By the microscope, the effects of this productive matter may be perceived in the seminal liquors of animals of both sexes. The seed of the female viviparous animals is filtered through the glandular bodies which grow upon their testicles, and these glandular bodies contain a large quantity of seminal fluid in their internal cavities. Oviparous females have, as well as the viviparous, a seminal liquor, which is still more active than the viviparous. The seed of the female is in general like that of the male, when, they are both in a natural state: they decompose after the same manner, contain similar organic bodies, and they alike offer the same phenomena.
All animal or vegetable substances include a great quantity of this organic and productive matter. To perceive it, we need only separate the inanimate parts in which the active particles of this matter are engaged. And this is done by infusing animal or vegetable substances in water. The salts will dissolve, the oils separate, and the organic particles will be seen by their putting themselves in motion. They are in greater abundance in the seminal liquors than in any other parts, or rather, they are less entangled by the inanimate parts. In the beginning of this infusion, when the flesh is but slightly dissolved, the organic matter is seen under the form of moving bodies, which are almost as large as those of the seminal liquors: but, in proportion as the decomposition augments, these organnic particles diminish in size and increase in motion; and when the flesh is entirely decomposed, or corrupted, these same particles are exceedingly minute, and their motion exceedingly rapid. It is then that their matter may become a poison, like that of the tooth of a viper, wherein Mr. Mead perceived an infinite number of small pointed bodies, which he took for salts, although they are only these same organic particles in astate of great activity. The pus which issues from wounds abounds with little insects, and it may take such a degree of corruption as to become one of the most subtle poisons; for every time this active matter is exalted to a certain point, which may be known by the rapidity and minuteness of the moving bodies it contains, it will become a species of poison. It is the same with the poison of vegetables. The same matter which serves to feed us when in its natural state, will destroy us when corrupted. Spurred barley, for instance, throws the limbs of men and animals into a gangrene who feed on it. It is also evident by comparing the matter which adheres to our teeth, which is the residue of our food, with that from the teeth of a viper or mad dog, which is only the same matter too much exalted, and corrupted to the last degree.
When this organic and productive matter is found collected in a great quantity in some part of an animal, where it is obliged to remain, it forms living beings which have been ever regarded as animals; the tænia, ascarides, all the worms found in the veins, liver, in wounds, in corrupted flesh, and pus, have no other origin; the eels in paste, vinegar, and all the pretendedmicroscopical animals are only different forms which this active matter takes of itself, according to circumstances, and which invariably tends to organization.
In all animal and vegetable substances, decomposed by infusion, this productive matter manifests itself immediately under the form of vegetation. Filaments are seen to form, which grow and extend like plants. Afterwards these extremities and knots swell and burst, to give passage to a multitude of bodies in motion, which appear to be animals; so that it seems as if all nature began by a motion of vegetation. It is seen by microscopical objects, and likewise by the expansion or unfolding of the animal embryo; for the fœtus at first has only a species of vegetable motion.
Sound food does not furnish any of these moving molecules for a considerable time. Several days infusion in water is required for fresh meat, grain, kernels, &c. before they offer to our sight any moving bodies; but the more matters are corrupted, decomposed, or exalted, the more suddenly these moving bodies manifest themselves; they are all free from other matters in seminal liquors; but a few hoursinfusion is required to see them in pus, spurred barley, honey, drugs, &c.
There exists therefore, an organic matter, universally diffused in all animal and vegetable substances, which alike serves for their nutrition, their growth, and their reproduction. Nutrition is performed by the intimate penetration of this matter in all parts of the animal or vegetable body. Expansion or growth is only a kind of more extended nutrition, which is made and performed as long as the parts have sufficient ductility to swell and extend; and reproduction is made by the same matter when it superabounds in the body of the animal or vegetable; each part of the body sends back, to the appropriate reservoirs, the organic particles which exceed what are sufficient for their nourishment. These particles are absolutely analogous to each part from which they are sent back, because they were destined to nourish those parts from hence, when all the particles sent back from, collect together, they must form a body similar to the first, since each particle is like that part from which it was detached; thus it is that reproduction is effected in all kinds of trees, plants, polypuses, pucerons, &c. where one individual can produce its like; and it isalso the first mode which Nature uses for the reproduction of animals which have need of the communication of different sexes; for the seminal liquors of both sexes contain all the necessary molecules for reproduction; but something more is required for its effectual completion, which is the mixture of these two liquors in some places suitable to the expansion of the fœtus which must result therefrom, which place is the matrix of the female.
There are, therefore, no pre-existing germs, no germs contained one in the other,ad infinitum; but there is an organic matter perpetually active, and always ready to form, assimilate, and produce beings similar to those which receive it. Animals and vegetables, therefore, can never be extinct; so long as there subsist individuals the species will ever be new; they are the same at present as they were three thousand years ago, and will perpetually exist, by the powers they are endowed with, unless annihilated by the will of the Almighty Creator.
HISTORY OF MAN.
CHAPTER I.
OF THE NATURE OF MAN.
Though so much interested in acquiring a thorough knowledge of ourselves, yet I do not know if man is not less acquainted with the human, than with any other existence. Provided by nature with organs, calculated solely for our preservation, we only employ them to receive foreign impressions. Intent on multiplying the functions of our senses, and on enlarging the external bounds of ourbeing, we rarely make use of that internal sense which reduces us to our true dimensions, and abstracts us from every other part of the creation. It is, however, by a cultivation of this sense alone that we can form a proper judgment of ourselves. But how shall we give it its full activity and extent? How shall the soul, in which it resides, be disengaged from all the illusions of the mind? We have lost the habit of employing this sense; it has remained inactive amidst the tumult of our corporeal sensations, and dried up by the heat of our passions; the heart, the mind, the senses, have all co-operated against it.
Unalterable in its substance, and invulnerable by its essence, it still, however, continues the same. Its splendor has been overcast, but its power has not been diminished: it may be less luminous, but its guidance is not the less certain. Let us then collect those rays, of which we are not yet deprived, and its obscurity will decrease; and though the road may not in every part be equally filled with light, we yet shall have a torch that will prevent us from going astray.
The first and most difficult step which leads to the knowledge of ourselves, is a distinctconception of the two substances that constitute our being. To say simply, that the one is unextended, immaterial, and immortal, and that the other is extended, material, and mortal, is only to deny to the one, what we affirm the other possesses. What knowledge is to be acquired from this mode of negation? Such negative expressions can exhibit no positive ideas: but to say that we are certain of the existence of the former, and that of the latter is less evident; that the substance of the one is simple, indivisible, and has no form, since it only manifests itself by a single modification, which is thought; that the other is a less substance than a subject, capable of receiving different forms, which bear a relation to our senses, but are all as uncertain and variable as the organs themselves; that is to say something; it is to ascribe to each such distinct and positive properties as may lead us to an elemental knowledge of both, and to a comparison between them.
From the smallest reflection on the origin of our knowledge, it is easy to perceive that it is by comparison alone we acquire it. What is absolutely incomparable, is utterly incomprehensible; of this God is the only example; heexceeds all comprehension, because he is above all comparison. But whatever is capable of being compared, contemplated, and considered relatively, in different lights, may always come within the sphere of our understanding. The more subjects of comparison we have for examining any object, the more methods there are for obtaining a knowledge of it, and with greater facility.
The existence of the soul is fully demonstrated. To be and to think are with us identically the same. This truth is more than intuitive; it is independent of our senses, of our imagination, of our memory, and of all our other relative faculties. The existence of our bodies, and of external objects, is however held in uncertainty by every unprejudiced reasoner; for what is that extension of length, breadth, and thickness, which we call our body, and which seems to be so much our own, but as it relates to our senses? What are even the material organs of those senses, but so many conformities with the objects that affect them? And with regard to our internal sense, has it any thing similar or in common with these external organs? Have the sensations excited by light or sound any resemblance to thattenuous matter, which seems to diffuse light, or to that tremulous undulation, which sound produces in the air? The effects are certainly produced by the necessary conformity there is between the eyes and ears, and those matters which act upon them. Is not that a sufficient proof, that the nature of the soul is different from that of matter?
It is then a certain truth, that the internal sensation is altogether different from its cause; as also, if external objects exist, they are in themselves very different from what we conceive them. As sensation therefore bears no resemblance to the thing by which it is excited; does it not follow, that the causes of our sensations, necessarily differ from our ideas of them? The extension which we perceive by our eyes, the impenetrability, of which we receive an idea by the touch in all those qualities, whose various combinations constitute matter, are of a doubtful existence; since our internal sensations of extension, impenetrability, &c. are neither extended nor impenetrable, and have not even the smallest affinity with those qualities.
The mind being often affected with sensations, during sleep, very different from thosewhich it has experienced by the presence of the same objects, does it not lead to a belief, that the presence of objects is not necessary to the existence of our sensations; and that, of consequence, our mind and body may exist independent of those objects? During sleep, and after death, for example, our body has the same existence as before; yet the mind no longer perceives this existence, and the body with regard to us, has ceased to be. The question is therefore, whether a thing which can exist, and afterwards be no more, and which affects us in a manner altogether different from what it is, or what it has been, may yet be a reality of indubitable existence.
That something exists without us, we may believe, though not with a positive assurance; whereas of the real existence of every thing within us, we have a certainty. That of our soul, therefore, is incontestable, and that of our body seems doubtful; because the mind has one mode of perception when we are awake, and another when we are asleep; after death, it will perceive by a method still more different, and the objects of its sensations, or matter in general, may then cease to exist with respect toit, as well as our bodies with which we have no further connection.
But let us admit this existence of matter; and that it even exists as it appears to our senses, yet by comparing the mind with any material object, we shall find differences so great, and qualities so opposite that every doubt will vanish of the latter being of a nature totally different, and infinitely superior.
The mind has but one form, which is simple, general, and uniform. Thought is this form; has nothing in it of division, extension, impenetrability, nor any other quality of matter; of consequence, therefore, our mind, the subject of this form, is indivisible, and immaterial. Our bodies on the contrary, and all other objects have many forms, each of which is compounded, divisible, variable, and perishable; and has a relation to the different organs, through which we perceive them. Our bodies, and matter in general, therefore, have neither permanent, real, nor general properties, by which we can attain a certain knowledge of them. A blind man has no idea of those objects, which sight represents to us; a leper, whose skin has lost the sense of feeling, is denied all the ideas which arise from the touch; and a deafman has no knowledge of sounds. Let these three modes of sensation be successively destroyed, yet the mind will exist, its external functions will subsist, and thought will still manifest it within the man so deprived. But divest matter of all its qualities; strip it of colour, of solidity, and of every other property which has any relation to our senses, and the consequence will be its annihilation. Our mind, then, is unperishable, but matter may, and will perish.
It is the same with all the other faculties of our soul when compared with the most essential properties of matter. As the mind wills and commands, so the body obeys in every thing within its power. The mind forms, at pleasure, an intimate union with any object; neither distance, magnitude, nor figure, can obstruct this union, when the mind wills it, it is effected in an instant. The body can form no union; whatever touches it too closely injures it; it requires a long time in order to approach another body; it every where meets with resistance, and obstacles, and from the smallest shock its motion ceases. Is will then nothing more than a corporeal movement; and is contemplation but a simple contact? How couldthis contact take place upon a remote object or abstracted subjects? How could this movement be accomplished in an indivisible instant? Is it possible to have a conception of motion without having a conception of space and time? Will, therefore, if it be a motion, is not a material one; and if the union of the mind with its object be a contact, it is effected at a distance: and is not this contact a penetration? qualities which are absolutely opposite to those of matter, and which of consequence can only belong to the immaterial being.
But I fear I have already dwelt too long on a subject which, by many, may be considered as foreign to our purpose; and it might be asked, "Ought Metaphysical Considerations on the Soul to find a place in a System of Natural History?" Were I conscious of abilities equal to the discussion of a topic so exalted, this reflection, I must own, would have little weight with me; and I have contracted my remarks only because I was afraid I should not be able to comprehend a subject so enlarged and so important in its full extent. Why retrench from the Natural History of Man the history of his noblest part? Why thus preposterously debase him; by consideringhim merely as an animal, while he is of a nature so different, and so superior, to that of the brutes, that those must be immersed in ignorance like the brutes themselves who ever thought of confounding them.
Man, as to the material part of his existence, certainly bears a resemblance to other animals, and in comprehending the circle of natural beings there is a necessity for placing him in the class of animals. Nature, however, has neither classes nor species; it contains only individuals. These species and classes are nothing but ideas which we have ourselves formed and established, and though we place man in one of such classes we do not change his being; we do not derogate from his dignity; we do not alter his condition. In a word, we only place him at the head of those who bear a similitude to him in the material part of his being.
In comparing man with the animal we find in both an organized body, senses, flesh, blood, motion, and a multitude of other resemblances. But these resemblances are all external, and not sufficient to justify a decision, that the human and the animal natures are similar. In order to form a proper judgment of the natureof each we ought to have as distinct a knowledge of the internal qualities of an animal as we have of our own. As the knowledge of what passes within animals is impossible to be attained, and as we know not of what order and kind its sensations may be, in relation to those of man, we can only judge from a comparison of the effects which result from the natural operations of both.
Let us, then, take a view of these effects; and, while we admit of all the particular resemblances, limit our investigation to the most general distinctions. It will be allowed, that the most stupid man is able to manage the most acute animal; he governs it, and renders if subservient to his purposes; and this, not so much on account of his strength or skill as by the superiority of his nature, and from his being possessed of reason, which enables him to form a rational system of action and method, by which he compels the animals to obey him. The strongest and most acute animals do not give law to the inferior, nor hold them in servitude. The stronger, it is true, devour the weaker, but this action implies no more than an urgent necessity, or a rage of appetite; qualities very different from that which produces a seriesof actions, all tending to the same end. Did animals enjoy this faculty, should we not see some of them assume dominion over others, and oblige them to furnish their food, to watch over them, and to attend them when sick or wounded? Now, throughout the creation of animals, there is no vestige of such subordination, no appearance that one of them knows, or is sensible of, the superiority of his own nature over that of others. It follows, then, that they must all be considered as of one nature, and that the nature of man is not only highly superior to that of the brute, but also entirely different from it.
Man, by outward signs, indicates what passes within him; he communicates his sentiments by speech, which is a sign common to the whole human species. The savage and the civilized man have the same powers of utterance; both speak naturally, and so as to be understood. No other animal is endowed with this expression of thought; nor is that defect owing, as some have imagined, to the want of proper organs. Anatomists have found the tongue of an ape to be as perfect as that of a man. The ape, therefore, if he had thought, would have speech, and if its thoughts hadaught analogous to ours, this speech would have an analogy to ours also. Supposing its thoughts were peculiar to its species, it still would hold discourse with those of its kind, a circumstance of which we should have heard had it been endowed with the powers of speech. So far then is the ape from having any thought like ours, that it has not even any order of thoughts of its own. As they express nothing by combined and settled signs, they of consequence are void of thought, or at most have it in a very small degree.
That it is from no organical defect animals are denied the gift of speech is plain, as several species of them may be taught to pronounce words, and even repeat sentences of some length. Perhaps many others might be found capable of articulating particular sounds[AG]; but to make them conceive the ideas which such sounds denote is an impracticable task. They seem to repeat and articulate merely as an echo, or an artificial machine. It is not in the mechanical powers, or the material organs, but in the intellectual faculties, that they are deficient.