The life of all flesh is the blood thereof. On this doctrine, expressed in the Mosaic books, many of the olden writers founded their hypothesis that blood was the principle of life. It is, however, more than probable that this opinion was derived from a more ancient ritual than the Levitical code, since we find a similar belief among the Parsees, Hindoos, and other Oriental nations of very remote antiquity, who no doubt owed the practice of abstaining from blood to the early patriarchs.

The Greeks and the Romans, if we take the expressions of their poets as being conclusive, entertained similar notions regarding the vital fluid; and the “purple death” of Homer and “the purple life” of Virgil, are phrases evidently applicable to this theory, which Critias, Empedocles, and their sects maintained. This opinion, however, does not appear to have dictated the expressions made use of by Moses. When he says “the life of all flesh is the blood thereof,” it merely signifies that when the blood is abstracted death ensues; a circumstance that must have been daily and hourly observed. It is probable that this injunction was promulgated to check the barbarous custom of devouring raw meat, which seems to have prevailed long before the Jewish legislator. We read in Genesis ix. 4, “Flesh with the life thereof, which is the blood thereof, shall you not eat.” From this circumstance we may infer that, like the Abyssinians of Bruce’s time, the Jews were in the habit of tearing and cutting flesh from live animals. Saul’s army was guilty of a similar practice. It therefore behoved their legislators to oppose a custom that increased the natural ferocity and cruelty of the nation they ruled.

This theory of the ancients has been frequently revived in modern times, and has not a little contributed to increase the mystery that veils the nature of our existence. Harvey, who discovered the circulation of the blood, was a convert to this doctrine; Hoffman also adopted it; and Huxham not only fully believed in it, but sought the immediate part of the blood that constituted life, and fancied that he had discovered it in its red particles. It was John Hunter, however, who first established the system on any thing like a rational basis, although his arguments on the subject have led to much doubt and illiberal controversy. “The difficulty,” says he, “of conceiving that blood is endowed with life while circulating, arises merely from its being a fluid, and the mind not being accustomed to the idea of a living fluid. I shall endeavour,” he continues, “to show that organization and life do not in the least depend upon each other; that organization may arise out of living parts and produce action; but that life can never arise out of or produce organization.” The errors of this doctrine are obvious, and have led many ingenious physiologists into a maze of idle wandering. The fact is, that life is the instrument of organization, or, in other words, organization is the result of life. The embryo could not be developed, did not the fluid that animates it possess a principle of vitality which it communicates to a body previously organized. In this confusion the word “life” has sometimes been applied to the power, and at others to the result. Without organization, life cannot be transmitted; and the moment the principle of life ceases, a disorganization, more or less rapid, ensues.

The doctrine of the vitality of the blood has very lately been maintained by several physiologists. Professor Schultz speaks of an active vital process which can be seen constantly going on between the individual molecules of the blood and the substance of the vessels; but Muller asserts that, during ten years, he examined the circulation of the blood in various parts, at every opportunity and with different instruments, but had never seen what Schultz describes—the constant assimilation, disappearance, and new formation of the globules; nor had Rudolphi, Purkinje, Koch, and Meyer, been more successful in their investigation; and Muller further maintains that the motion of these red particles in the circulation is purely passive, which may be proved by compressing the vessels of the limb, or the limb itself.

Eber and Meyer pretended that these red particles were infusory animals. On this important and curious subject I shall quote Muller’s opinion: “The question whether the blood be living fluid or not, calls to mind a critical state of our science. Every thing which evidences an action which cannot be explained by the laws of inorganic matter, is said to have an organic, or, what is the same thing, a vital property. To regard merely the solids of the body as living, is incorrect, for there are strictly no organic solids; in nearly all, water constitutes four-fifths of their weight. Although, then, organic matter generally be considered as merely ‘susceptible of life,’ and the organized parts as ‘living,’ yet the blood also must be regarded as endowed with life, for its action cannot be comprehended from chemical and physical laws. The semen is not merely a stimulus for the fructification of the egg, for it impregnates the eggs of the Batrachia and fishes out of the body; and the form, endowments, and even tendencies to disease, of the father, are transferred to the new individual. The semen, therefore, although a fluid, is evidently endowed with life, and is capable of imparting life to matter. The impregnable part of the egg, the germinal membrane, is a completely unorganized aggregation of animal matter; but, nevertheless, is animated with the whole organizing power of the future being, and is capable of imparting life to a new matter, although soft, and nearly allied to a fluid. The blood also evidences organic properties; it is attracted by living organs, which are acted upon by vital stimuli. There subsists between the blood and the organized parts a reciprocal vital action, in which the blood has as large a share as the organs in which it circulates.”

This doctrine is, no doubt, ingenious, but I do not consider it as conclusive. It is not because that in inflammation, the blood becoming solid, forming pseudo membranes, which are shortly after supplied with a proportion of blood-vessels, blood possesses life. If this adventitious coagulation were not supplied with blood, it would prove a foreign body; but it is not, therefore, shown that the circumstance of its possessing vitality after its formation is a proof of the life of the blood; it only shows that the secretions of the blood are endowed with a susceptibility of life, when having assumed a solid form, needing vessels for its support. I shall not dwell longer on a professional question of great interest, but which would need a development foreign to the nature of these sketches.

The Greeks had distinct appellations for the cause and result of life; the former they termed ???? the latter ???. The essential nature of life is, and most probably will ever remain, an impenetrable mystery. Living matter is endowed with a property which we call life; but to find out to what we may venture to attribute this property, is a vain and hypothetical attempt. Equally vain and absurd have been the endeavours to ascertain whether life began at the creation to be subsequently transmitted from parent to offspring, or owed its origin to a spontaneous generation from matter. Many ancient philosophers considered matter as eternal: such was the doctrine of the Pythagoreans; amongst whom we must particularly notice Lucanus Ocellus, whose system, developed in a work written in the Attic dialect, was adopted by Aristotle, Plato, and Philo-JudÆus. This work was first translated into Latin by Nogarola. These doctrines led to the unanswerable question, What was this matter—this invisa materia—from which every thing visible has proceeded? Has it existed from all eternity, or has it been called into being by the Creator? Has it uniformly exhibited its present harmonious arrangement, or was it once a waste and shapeless chaos? Was this matter endowed with intelligence as a whole, or in its separate fractions?

The eternity of matter was maintained by these philosophers from the belief that no thing could be created out of nothing, and that no thing could ever return to nonentity. Such was the doctrine of the Epicureans, of Democritus, and of Aristotle. The poets were of the same belief; and Lucretius expresses himself as follows:

Ubi viderimus nihil posse creari
De nihilo, tune, quod sequimur, jam rectiÙs inde
Perspiciemus.

Persius maintains the same idea:

Gigni
De nihilo nil, in nihilum nil posse reverti.

This dogma was no doubt transmitted to the Greeks from the East; and, to the present day, it is a doctrine of the Brahminical creed, clearly expressed in the following terms in their Yajur Veid: “The ignorant assert that the universe in the beginning did not exist in its author, and that it was created out of nothing. O ye, whose hearts are pure! how could something arise out of nothing?” The fathers of the church embraced a similar belief; and Justin Martin says that “the word of God formed the world out of unfashioned matter. This Moses distinctly asserts, Plato and his adherents maintain, and ourselves have been taught to believe.”

Such was the doctrine of the schools that professed the eternal nature of matter. Other philosophers supported as warmly a different opinion. Thales of Miletus, Zeno of Citium, Xenocrates, and Dicearchus the Messenian, insisted that the human race had a first origin at a period when mankind did not exist. According to this hypothesis, the universe is an emanation or extension of the essence of the Creator. Zeno and the Stoics attribute this creation to the universal elements of fire and water. Anaximander the Milesian asserted that the primitive animals were formed of earth and water mixed together, heated and animated by the solar rays; these aquatic creatures became amphibious, and were gradually transformed into the human races. Strange to say, this extraordinary idea has found proselytes even in our days, and was advocated by Professor De Lamark in his Zoological Philosophy. This fancy pervades the poetry of the ancients. Homer makes Tethys, the wife of Ocean, the daughter of Uranus and Terra, the first parents; and Hesiod, in his Cosmogony, raises Venus and Proteus from the foam of the sea.

The vital and intellectual fire of the ancients that animated all living beings was admitted by most of their physicians, especially by Hippocrates, Galen, and AretÆus. Aristotle describes an universal creative agent in all the elements, the source of life upon earth, and of the celestial movements in the firmament. Descartes, in modern times, maintained that a vital flame existed in the heart of every animal. This fire, and the genial warmth that it diffused, was considered the soul of the universe; and on this subject Gassendi expresses himself as follows: “Si quis velit talem calorem etiam animam dicere, nihil est similiter quod vetet.”

It was natural for man, even in an uncivilized state, to attribute to solar heat the same influence on animals as was manifest in its actions upon plants. When life had fled, the inanimate corpse was cold, and caloric was therefore considered the principle of vitality. It was from this conviction that we find the sun and fire objects of adoration both in ancient times and amongst savages to the present day. Fire is idolized by the Tartars, and various African tribes. The Yakouts, a Siberian horde, believe that the deity of good and evil has taken his abode in this supposed element. The Columbian Indians were fire-worshippers; and Pallas informs us that the Chinese on the confines of Siberia held it in such religious respect, that they never attempted to extinguish it even when their dwellings were burning.

The doctrine of man and the universe having been created an emanation of the Creator, renders the Creator material, or matter itself; matter being considered intelligent, and susceptible of this organization. This was the belief of the Brahmins, and was no doubt transmitted to the Academic and Eleatic schools of Greece by Pythagoras. We find in the Yajur Veid, already alluded to, the following passages, that clearly demonstrate this belief: “The whole universe is the Creator, proceeds from the Creator, and returns to him. The ignorant assert that the universe in the beginning did not exist in its author, and that it was created out of nothing. O ye, whose hearts are pure! how could something arise out of nothing? This first being alone, and without likeness, was the All in the beginning. He could multiply himself under different forms. He created fire from his essence, which is light.” And further: “Thou art Brahma! thou art Vishnu! thou art Kodra! thou art the moon! thou art substance! thou art Djam! thou art the earth! thou art the world!”

These Brahminical doctrines were, beyond doubt, also held by the Greeks. In a poem ascribed to the fabled Orpheus we find the following lines, translated by Mason Good with as much correctness as elegance:

Jove first exists, whose thunders roll above,
Jove last, Jove midmost; all proceeds from Jove.
Female is Jove—immortal Jove is male;
Jove the broad earth—the heavens’ irradiate pale.
Jove is the boundless spirit, Jove the fire,
That warms the world with feeling and desire;
The sea is Jove, the sun, the lunar ball;
Jove king supreme, the sovereign source of all.
All power is his; to him all glory give,
For his vast form embraces all that live.

It may be easily imagined that a subject so recondite and obscure must have led philosophers into the wildest speculations. By some, life was considered as the result of a general consent or harmony between the different organs of which the vital frame is formed; while, as we have seen, many have attributed its phenomena to the blood. That blood, to a certain extent, is endowed with vitality is beyond a doubt; Hunter has endeavoured to prove the fact by various experiments. It is capable of being acted upon and contracting like the solid fibres; this we daily witness when blood is coagulated and comes into contact with the atmosphere. It preserves an equality of temperature in whatever medium an animal may move. He also has shown that this fluid can form solid vessels of every description; and its life is also proved by the death inflicted when any excessive stimulus destroys the muscular fibre. Thus, in a body struck with lightning, the muscles remain flaccid and uncontracted, while the blood preserves its fluidity, and is left uncoagulated.

All this specious reasoning shows that blood is a living fluid, but does not in the slightest degree demonstrate to what principle this vitality is to be attributed. It merely proves that every part of a living animal, whether solid or fluid, is endowed with a certain degree of life; but leaves us in impenetrable darkness as to the nature of life. The one cannot be killed without the other; and, as Mason Good justly observes, “that which is at one time alive, and at another dead, cannot be life itself.” It is clear that life cannot exist without blood, but at the same time it is equally evident that the blood is merely a secretion of the living system, and dependent upon the action of the solids, which influence its quantities and properties.[29]It is from this notion of the vitality of the blood that the absurd idea of transfusing it was first conceived. Transfusion consisted in the injection of the arterial blood of young and healthy animals into the veins of the aged and the debilitated. It was about forty years after the discovery of the circulation of the blood by Harvey that this singular project was tried upon animals, and afterwards upon man. Medicated liquids had already been introduced in Germany into the system by this method, principally by Wahrendorf. Dr. Christopher Wren, an English physician, was the first who proposed the injection of blood, and Dr. Lower put it into practice. The result of his experiments seemed to warrant their adoption. An animal was drained of a considerable proportion of blood, and lay faint and expiring; but the blood of another animal being thrown into the languid system, active circulation was restored, and the patient ran about with as much facility as before the experiment. When too great a quantity of blood was injected, the creature became drowsy, and shortly after died of plethora.

These experiments were reported by the transfusers with many absurd details. In one case a simpleton had become witty by a supply of lamb’s blood; in another, an old mangy cur was cured by the vital fluid of a young spaniel; a blind old dog, transfused by a Mr. Gayant, bounded and frisked about like a young pup. Dr. Blundel seriously conceived that this operation might be practised with great advantage in cases of hÆmorrhage, more especially in women.

Of late years these curious experiments have again been tried with singular results. Prevost and Dumas have shown that the vivifying power of the blood does not reside so much in the serum as in the red particles. An animal bled to syncope, is not revived by the injection of water or pure serum of a temperature of 68° Fahrenheit into its vessels. But if blood of one of the same species is used, the animal seems to acquire fresh life at every stroke of the piston, and is at last restored. Diemenbach has confirmed these experiments. It is also stated by these physiologists, that revival takes place likewise when the blood injected had been previously deprived of its fibrin.

Another very singular fact has been elicited by these experiments; blood of animals of a different genus, of which the corpuscules, though of the same form, have a different size, effects an imperfect restoration, and the animal generally dies in six days.

The injection of blood with circular corpuscules into the vessels of a bird (in which the corpuscules are elliptic and of a larger size) produces violent symptoms similar to those of the strongest poisons, and generally death, which ensues indeed instantaneously, even when a small quantity only of the blood has been injected. Such, for example, was the effect of the transfusion of some blood of the sheep into the veins of a duck; while in many cases in which the blood of sheep and oxen were injected into the vessels of cats and rabbits, these animals were revived for a few days. The fact of the blood of mammalia being poisonous to birds is very remarkable; it cannot be explained mechanically. The injection of fluids containing globules of greater diameter than the capillary vessels of the injected animal most probably produces death, by obstructing the pulmonary vessels and producing suffocation; but the globules of the blood in mammalia are even smaller than those of birds. In Dieffenbach’s experiments, pigeons were killed by a few drops only of the blood of mammalia, and the blood of fishes, it is asserted, is as fatal to mammalia as to birds.

These interesting facts have been confirmed by Dr. Bischoff. In all his experiments made with the fresh blood of mammalia, birds died within a few seconds after the transfusion, with violent symptoms resembling those of poisoning; but when, instead of the fresh unchanged blood, he injected blood from which the fibrin had been removed by stirring, and which was heated to a proper temperature, he was surprised to find that no such symptoms were produced, the animal not appearing to suffer any inconvenience.

It seems indeed from these experiments, that the blood of an animal of a different class, is not adapted for the operation.

When transfusion was first proposed in France, it met with furious opponents; and LamartiniÈre declared that it was a barbarous operation proceeding from Satan’s workshop. The controversy between the transfusers and their adversaries was at length carried on with such virulence, that in 1668 the practice was forbidden by a decree of the ChÂtelet, unless the operation had been sanctioned by the faculty of Paris. In Italy it continued to be in vogue. Riva and Manfredi frequently performed it; and a physician of the name of Simboldus submitted himself to the experiment. According to the accounts given by the patients who had been thus injected, they first experienced an increased heat with violent pulsation, profuse perspiration with pains in the loins and stomach, and a sense of suffocation. Violent vomiting frequently arose, and the patient gradually sank into a torpid and heavy sleep. Whatever may be the theoretical ingenuity in favour of this practice, it is not probable that it will ever be adopted.

While young blood was thus supposed to give fresh vigour to the aged, the heat communicated by young persons to debilitated bedfellows was also resorted to. This practice seems to have been founded on observation. It is an acknowledged fact that an uncommon depression of vital power takes place in the young when such experiments are tried. This abstraction of vital power is frequently observed in young females married to very old men. In illustration of this fact, Dr. Copeland relates the following case: “I was a few years since consulted about a pale, sickly, and thin boy of about five or six years of age. He appeared to have no specific ailment; but there was a slow and remarkable decline of flesh and strength, and of the energy of all the functions,—what his mother very aptly termed ‘a gradual blight.’ After inquiring into the history of the case, it came out that he had been a very robust and plethoric child up to his third year, when his grandmother, a very aged person, took him to sleep with her; that he soon afterwards lost his good looks, and that he had continued to decline progressively ever since, notwithstanding medical treatment. I directed him to sleep apart from his aged parent, and prescribed gentle tonics, change of air, &c., and the recovery was very rapid.”

This selfish indulgence of the aged in endeavouring to deprive their young bedfellows of heat and strength has been often remarked; and young women thus circumstanced have shrewdly suspected the cause of their debilitated condition. It is extremely probable that in these cases electricity is conducted from one body to another. This hypothesis is in some degree confirmed by the experiments made upon Casper Hauser by Von Feuerbach. This Casper Hauser had been kept from infancy until he was eighteen years of age in a perfectly dark cage, without leaving it, and where he never saw a living creature or heard the voice of man. He was restricted from using his limbs, his voice, his hands, or senses; and his food consisted of bread and water only, which he found placed by him when wakening from his sleep. When exposed in Nuremberg, in 1828, he was consequently at eighteen years as if just come into the world, and as incapable of walking, discerning objects, or conveying his impressions, as a newly born infant. These faculties, however, he soon acquired; and he was placed under an able instructor, who has recorded his singular history. Darkness had been to him twilight. The light of day was at first insupportable, inflamed his eyes, and brought on spasms. Substances, the odour of which could not be perceived by others, produced severe effects upon him. The smell of a glass of wine, even at a distance, occasioned headache; of fresh meat, sickness; and of flowers, a painful sensation. Passing by a churchyard with Dr. Daumer, the smell of dead bodies, although altogether imperceptible to the doctor, affected the young man so powerfully as to occasion shudderings, followed by feverish heat, terminating in a violent perspiration. He retained a great aversion, owing to their disagreeable taste and smell, to all kinds of food excepting bread and water.

When the north pole of a small magnet was held towards him, he described a drawing sensation proceeding outwards from the epigastrium, and as if a current of air went from him. The south pole affected him less, and he said it blew upon him. Professor Daumer and Hermann made several experiments of the kind, calculated to deceive him, and, even although the magnet was held at a considerable distance from him, his feelings always told him very correctly. These experiments always occasioned perspiration and a feeling of indisposition. He could detect metals placed under oil-cloths, paper, &c. by the sensation they occasioned. He described these sensations as a drawing, accompanied with a chill, which ascended, according to the metal, more or less up the arm, and attended with other distinctive feelings, the veins of the hand exposed to the metal becoming visibly swollen.

The variety and multitude of objects which at once came rushing upon his attention when he thus suddenly came into existence, the unaccustomed impressions of light, free air, and sense, and his anxiety to comprehend them, were too much for his weak frame and acute senses: he became dejected and enfeebled, and his nervous system morbidly elevated. He was subject to spasms and tremors, so that partial exclusion from external excitements became for a time requisite. After he had learned regularly to eat meat, his mental activity was diminished; his eyes lost their brilliancy and expression; the intense application and activity of his mind gave way to absence or indifference, and the quickness of apprehension became diminished. It may be questioned whether this alteration proceeded from the change of diet, or the painful excess of excitement that had preceded it.

Among the various doctrines regarding the creation of animals, that of Panspermia was most ingenious and attractive. According to this theory, maintained by Anaxagoras and Heraclitus, all bodies contained the germ or the organic molecules necessary for their generation. Hippocrates favoured this idea, as plainly appears in his book de DiÆtÂ; and in modern times Perrault, GÉsik, Wollaston, Sturm, and other physiologists, have endeavoured to revive the doctrine, of which the organic molecules of Buffon and the living molecules of Ray were merely modifications. The expression in Genesis which sanctions the belief that the earth spontaneously germinated its productions, cannot be referred to the animal kingdom. Were this the case, similar animals would be found in every quarter of the globe. Spontaneous generation was also attributed to putrefaction; and Virgil describes the manner in which AristÆus drew forth a swarm of bees from the corrupted entrails of a heifer. Pliny admits the spontaneous creation of rats, mice, frogs, and other small tribes of animals. These errors, however, were soon dispelled by the light thrown on the subject by the microscopic experiments of ValisnÉri, Swammerdam, RÉaumur, and many other naturalists, who discovered sexual organs in all these supposed self-created individuals.

This doctrine was the foundation of the classification of the generative principle into equivocal and univocal generations,—the former the effect of putrefaction, but which in reality was univocal, since it was soon ascertained that this production arose from the incubation of numerous eggs deposited by various insects and animalculi in these corrupted bodies. The following experiment afforded a convincing proof of the fact: A piece of meat was placed in an open vessel, and another in a vase hermetically closed; so soon as these animal substances entered into decomposition, myriads of insects pullulated in the exposed meat, whereas that which was protected from external agency remained free from this invasion.

It is a recognised fact that it is only through organized beings that organization can be transmitted; for how can corrupt substances, dead and deprived of vitality, give life to any organized matter? Generation is life; putrescence is death. By a law of nature, generation may be said ultimately to destroy the generative powers; a striking illustration of mortality, since life is transmitted at the expense of our very existence, and many individuals in the catenation of organized beings perish the very moment that they have tended to perpetuate their race. Death advances with rapid strides in the very ratio of the energies of life; and the surest method to attain longevity is to be sparing in the exercise of our exhausting faculties.

Et quasi vitaÏ lampada tradunt.

Latent or insensible life, such as that of the seeds of plants, or the animal enveloped in its egg, may last for a number of years, so long as they are able to germinate; here vitality is not worn out by relative life. Various species of the snail, the wheel-polybe, the tile-eel, and divers animalcules, have been kept apparently dead, and in the form of dried preparations, withered and hardened, for months and even years, but have afterwards been restored to life by the agency of warmth, moisture, and other stimulants. Snails have been thus reanimated after a lapse of fifteen years; and Bauer revived the Vibrio tritici, after an apparent death of five years and eight months, by merely soaking it in water. Adders have been found in hard winters not only completely frozen but absolutely brittle, yet have been restored to life when thawed. A shower of fragments of ice has fallen at Leicester, containing the horsehair eel, with the nuclei of a greater number. Colonel Wilks found eggs in the solid rocks of St. Helena susceptible of being hatched. The vitality in the seeds of plants is truly amazing; barley taken out of the bodies of mummies, Indian corn discovered in the tomb of a Peruvian Inca, and the bulb of an onion found in the hand of a mummy 3000 years old have been sown and have thriven luxuriantly. The most intense heat cannot destroy the vital property. The seeds of roasted apples, the kernels of baked prunes and boiled elder-berries have germinated. Sir John Herschel found that the Acacia Lophanta lived after having been steeped in boiling water for twelve hours, and Ludwig informs us that the seeds of a species of cedar only germinated after ebullition. Fresh-water shells have been found in the thermal waters of Gastein at a temperature of 117°, and Niebuhr found a conferva growing in water at 142°. Raspberry-seeds taken from the corpse of an ancient Briton, contemporaneous with the Druids, have produced fruit when recommitted to the earth.

Some have endeavoured to explain the resurrection of the dead by these natural phenomena; forgetting that in these instances no corruption or actual disorganization had taken place. Stahl expresses himself in the following words when defining life: “Life is formally nothing more than the preservation of the body in mixture, corruptible indeed, but without the occurrence of corruption;” and in Junker we find, “What we call life is opposite to putridity.”

The next theory attributed the principle of life to a subtle gas or aura. This doctrine constituted one of the principles of the Epicurean philosophy, and was illustrated by Lucretius in his poem on the Nature of Things:

Nam penitÙs prorsÙm latet hÆc natura, subestque;
Nec magis hac infra quidquam est in corpore nostro;
Atque anima est animÆ proporrÒ totius ipsa.

According to these notions, there existed a volatile principle that bore no specific name, but was diffused through every part of living bodies, more subtile than heat, air, or vapour. In later times this same gaseous agent received various appellations. Van Helmont designated it as the aura vitalis, while other philosophers called it the aura seminalis and the aura sanguinis. The archeus faber of Van Helmont, the astrum internum of Crollius, the principium energoumenon of Michael Alberti, the substantia energetica naturÆ of Glisson, may all be referred to this unseen but powerful agency. Hippocrates called it f?s??, or nature, which he elsewhere denominates e?????ta. It was also the d??a?? ??t??? of Galen. This soul, or breath, or spirit, directed and preserved the whole economy; and Chrysippus asserts that it acted like salt upon pork.

Modern chemistry has sought this principle in specific agents. Caloric, or the matter of heat; oxygen, or the vital part of atmospheric air, first discovered by Priestley, and explained by Lavoisier; and finally, the fluid collected by the Voltaic trough, were then considered as the principle of life. The experiments of Professor Galvani of Bologna, in which he produced the phenomena of life many hours after death, induced many physiologists to maintain that the identity that existed in galvanic electricity and the nervous influence, proved that this aura was the creative agent in our economy.

The late experiments of Mr. Crosse seemed to show that insects were produced in silicate of potash under a long-continued action of voltaic electricity. Now whether this be really the case or not, it is grievous in the present enlightened age, to see these experiments and the assertions that resulted from them, denominated the work of atheism, and the labour of another Frankenstein!—I do not suppose for one moment that Mr. Crosse pretended to have discovered the power of imparting life, but merely of having developed a vital principle in substances supposed to be inorganic. Every experimentalist who thus develops the vital principle may be said to bestow life, without being exposed to the absurd charge of impiety.—The man who brings forth chickens from the incubation of eggs, instead of eating them; the physiologist who rots a piece of meat to develop myriads of living beings in the putrid nidus, might just as well be called an atheist.

While naturalists were thus groping in nature’s dark labyrinth, endeavouring to account for the wonders of the natura naturans, that divinity of the Stoics that Lucan thus describes,

Superos quid quÆrimus ultrÀ?
Jupiter est quodcumque vides, Jovis omnia plena,—

other wise men fancied that they had actually discovered the seat of life, which, according to their fanciful speculations, they had lodged in certain organs. The nervous system, the spinal marrow, the brain, the heart, were all and each of them considered in turn as the head-quarters of vitality; while the workshop of alimentation, or much-abused stomach, did not pass unnoticed and unhonoured. The heart of a turtle, and of some reptiles, has been seen contracting and dilating hours after its extraction from the body; the stomach has been excited into an action bearing some analogy to vomiting, when separated from the trunk; but all these curious phenomena, explained and accounted for (in some measure, at least) by physiology, do not tend to prove that any one organ, or any chain of organs, is possessed of separate vitality independent of the general principle of life. The brain, which has been regarded as the chief seat of this principle, is not always essential to life; for although man perishes, or at least his vital functions cease to act, when he is decapitated,[30] yet various birds and reptiles continue to live for hours and days after the head has been severed from the body, while we actually behold a regeneration of the head in the earth-worm. Moreover, we have upon record many cases of acephalous children, or born without any head; and anencephalous children who lived (for a short time, it is true) without any brains. Fontana removed the entire brain of a turtle, yet it lived six months, and walked about as before.

Sandiford had divided acephalous animals into three classes: the first, in which the head was wanting; the second, where other organs were also missing; and the third, where the foetus presented an unformed mass. In the acephalous twin described by BÉclard, no liver, spleen, stomach, or oesophagus could be discovered, and the intestinal tube commenced at the superior extremity of the body. The infant had ten ribs on each side, and regular nerves arose from the spinal marrow. Although headless animals may not be gifted with intellectual faculties evident to our senses, yet they clearly live and feel. The zoophytes and polypes, without brains or heads, possess irritability and sensibility; they can seek their food, seize it, reject what is not edible, are susceptible of the powers of light and heat, can contract their fibres when touched or injured, and, in short, manifest various innate or instinctive powers. Gall has maintained that the passions resided in the brain, and, therefore, that brainless animals did not experience their influence. This is a bold assertion. Can he prove that worms, insects, zoophytes, that possess only what is called a ganglionic system, are strangers to instinctive fears and partialities? I apprehend that it will be found that passions belong to instinct much more than to our volition.

It is nevertheless true that animals may be killed by wounding the spinal marrow, by the process commonly called “pitting.” This practice may be traced to high antiquity; and Livy informs us that when the Carthaginian troops were routed, Asdrubal ordered their unmanageable elephants to be destroyed by driving the point of a knife between the junction of the head and spine.

From these observations it will appear quite clear that life has no necessary connexion with sensation, although the latter cannot be experienced without the former. Vegetables are endowed with vitality; but we have no reason to suppose that they feel. It is also more than probable that, as the degree of intelligence decreases, the intensity of the corporeal feelings are also diminished. Did not this scale of sensibility exist, insects could not live under the supposed agonies that the entomologist daily inflicts. This supposition does not rest upon indefinite reasoning, for in our own race we observe that those parts which are gifted with a reproductive power are possessed of the smallest degrees of sensation; and the cuticle, the hair, the beard, and the nails will even grow after death. This fact may calm the apprehensions of those very humane persons who look upon experimental physiologists as very monsters of barbarity. Vaillant took out the intestines of a locust, and stuffed it with cotton, then fixed it down in his box with a pin, yet, five months after, the insect moved its feet and antennas. Spallanzani has shown that the snail can renew its head.

All this confusion in theories and wandering of the imagination have arisen from our confounding the vital principle, of which we know nothing, with the phenomena of sensation, for which patient and calm investigation may account. That there does exist a principle of life that animates, vivifies, and preserves all living bodies, until its powers cease, no one can deny; although to find out its nature is a vain pursuit, as idle as our endeavours to penetrate into the causes of causation. As Richerand observes, “its essence is not designed to preserve the aggregation of our constituent molecules, but to collect other molecules, which, by assimilating themselves to the organ that it vivifies, may replace those which daily losses carry off, and which are employed in repairing and augmenting them; the word vital principle is therefore not designed to express a distinct being, but denotes the totality of powers alone which animate living bodies, and distinguish them from inert matter, the totality of properties and laws which govern the animal economy.”

Of all the doctrines upon this abstruse subject (of which I have noticed the principal ones), that of the pre-existence of an organic germ appears the most plausible, or at any rate the easiest to conceive. It was from this conviction that the ancients held as an axiomatic principle Omnia ex ovo. It is upon this theory that Buffon rested his organic molecules, and Ray his vital globules. The primitive lineaments of organization may be traced in the egg, even before it is fecundated. The embryo that we find in its involucra is soft, flexible, ready to receive the plastic impression of the vivifying secretion,—the fecundating agency that imparts existence and all its wondrous attributes, to the pre-existing ova, the ova subventanea. It does not appear that the first organ of the embryo which exhibits the living principle is the heart, hence denominated in the foetus the punctum saliens; the principle of life has probably organized every molecule of the animal long before this supposed fountain of vitality had been seen to flow. It is more likely that the nervous system has received the first impressions imparted by the fecundating secretion, which the ancients supposed to have been a direct emanation from the brain, and bearing in its vivifying molecules the life of every part of the being it was about to organize; thus Valescus: “Sperma hominibus descendit ex omni corporis humore, qui fit ex subtiliori naturÂ. Habet autem hoc sperma nervos et venas proprias attrahentes se À toto corpore ad testiculos—À membris disconditur principalibus—À corde, epate, cerebro mittuntur spiritus, ex quibus resultat spiritus informativus, et non aliter nisi cum spermate—ergo ab iis principaliter sperma disconditur.”

Such were the doctrines on this curious subject until the days of Fabricius d’Acquapendente and Harvey. Buffon, however, exerted all his eloquence to revive the theory. The following are the notions of this elegant writer, who unfortunately only studied natural history in books and cabinets. He maintains that there exist two sorts of matter,—the one living, the other dead: the first enjoying a permanent vitality; the second universally spread, passing from vegetables to animals through the channels of nutrition, and returning from animals to vegetables through the medium of putrefaction,—thus in a constant state of circulation to animate living beings. This vital matter exists in determined quantities in nature, and is composed of an infinity of organic molecules, primitive, living, active, incorruptible, and in relation, both as regards action and numbers, with the molecules of light, and enjoying an immutable existence, since the usual causes of destruction can only affect their adherence. It is these molecules which, being cast in regular moulds, constitute all the organized bodies that surround us. According to this doctrine, development and growth are only a change of form operated by the addition of organic molecules; nutrition, the preservation of this form by the accession of fresh molecules that replace those that are destroyed; generation, the combination of these particles; and death, their separation from cohesion and association.

This ingenious system is not dissimilar to that of Maupertuis, who thought that the mysteries of generation could be explained by the usual laws of elective attraction. Various were the physical, metaphysical, and moral batteries raised against this visionary fabric. One single fact was sufficient to overthrow it. We constantly see parents deficient in a limb, or misshapen, producing perfect offspring; if each part of the economy was to transmit to its progeniture molecules similar to itself, the child would naturally be visited with the imperfection of the parent.

Notwithstanding these fallacies, we cannot but admit that chemical and molecular attraction constitute the principle that harmonizes all organized bodies. Generation is simply a function of organization and life. Organized bodies alone can generate. The living only can impart life. Animals and plants transmit to their descendants their several properties; and the inheritance of organization departs with the vital spark. Life is the property of no one; it is a transmitted heir-loom that never perishes; it resembles a torch that communicates an eternal flame while consuming itself. Organized beings have justly been considered the fuel of the universal vital fire, and we all are the daily bread of that monstrous animal called the world. All are ingulfed in that vortex which Beccher has called the “circulus Æterni motus” Metempsychosis was simply an illustration of this fact recognised in all ages in the East, and taught in European schools by Pythagoras. Nothing perishes; and even combustion produces fresh combinations.

Poetical philosophy has considered Love as the source and arbiter of life, and the Venus Generatrix the fount of our existence. Lucretius recognises this power in the following lines:

Per te quoniam genus omne animantÛm
Concipitur, visitque exortum lumina solis.

Then again,

Omnibus incutiens blandum per pectora amorem,
Efficis ut cupidÈ generatim sÆcia propagent.

Virey, a delightful French physiologist, seems to partake of this mythological opinion in the following passage: “L’amour est l’arbitre du monde organique; c’est lui qui dÉbrouille le chaos de la matiÈre, et qui l’impregne de vie. Il ouvre et ferme À son grÉ les portes de l’existence À tous les Êtres que sa voix appelle du nÉant, et qu’il y replonge. L’attraction dans les matiÈres brutes est une sorte d’amour ou d’amitie analogue À celle qui reproduit des Êtres organisÉs. Ainsi la facultÉ gÉnÉrative est un phÉnomÈne gÉnÉral dans l’univers; elle est reprÉsentÉe par les attractions planÉtaires et chimiques dans les substances brutes, et par l’amour ou la vie dans les corps organisÉs.”

According to our amatory neighbours, the word ame, or soul, comes from amor and amare, and amare is derived from animare; hence animation and animal may be syllogistically referred to love.

I know not how far this etymological disquisition may illustrate the history of their enfans trouvÉs, or our foundling hospitals, the inmates of which are generally uncommonly ill favoured by beauty. The offspring of the aforesaid Venus Generatrix must have been especially ungrateful; and if it be true that Julius CÆsar was her son, he certainly exerted his best endeavours to depopulate his mother’s territories.