Popular Science Monthly/Volume 2/April 1873/On the Transfusion of Blood

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IN all ages the most different opinions as to the seat and the principle of life have been expressed; yet, the systems bequeathed to us by the ancients on this subject contain a general belief, simple enough to be very widely shared, and seemingly well founded enough to endure for centuries. One fact of commonest observation death resulting from haemorrhage gave rise to the notion that life dwells solely in the blood. Homer's heroes breathed out their souls with their blood; among the Hebrews, as among the Greeks, offering the sacrifice of a life, and shedding the blood of a victim, were equivalent expressions. On this point the religions of the West have consecrated the belief of all ages and all people; a verse in Leviticus thus sums it up: "The life of all flesh is in the blood."

From Galen to Harvey, men of science supposed that the heart only sends out the fluid of the blood from the centre to the surface. In their theories, the blood was incessantly formed and renewed within the liver, and was impelled by centrifugal force into the veins and arteries alike. Harvey first demonstrated that the blood returned in its course. "It moves," he said, "in the same circle, as the planets all describe the same orbit in moving through space." The idea of the transfusion of blood takes its starting-point from the discovery of Harvey. As soon as it was known that the blood can return to the heart, and be taken up again by the vessels, what was more natural than to seek to introduce it into a diseased body? Is not the blood still regarded as the sole principle of life, as it was in the early ages of medicine? And, since it can be transfused in kind, we shall be able to restore health, to heal disorders, perhaps, even to lengthen life. In a moment of pride the human mind believes it has penetrated the secret of life, and supposes that henceforward it will be its master. The most famous alchemists of the middle ages never surrendered themselves to hopes so wild. Besides, the sixteenth and seventeenth centuries saw the birth of so many discoveries in natural sciences, that nothing seemed impossible. The schools of medicine enter with feverish ardor on these questions, so full of promise; but, amid the light that bursts upon them, they often neglect that severe observation of facts which led to the discovery of the circulation. Physicians of that day trouble themselves very little with inquiries whether the ancient notions about the blood are true or false; they accept them without reserve, and publish them abroad with those forms of discussion and those obsolete principles which brought upon them the well-deserved ridicule of our satirists. Medicine and physiology in that era were treated under the form of philosophic argument, science and imagination were blended, and "reasoning banished reason." The history of transfusion, at its beginning, looks like an important but empirical discovery; new experience rests simply on scholastic discussions, the true mingles with the false, and, after the spectacle of a barren contest presented by detractors and enthusiasts, transfusion was proscribed, and doomed to oblivion; and it will be long before its recovery, for the true scientific method has not yet been found.

In the last half-century we have returned to the method of observation; nor is that method now, as it was in Harvey's time, the privilege of a few savants; it has become the guide of all men of science in our day, and the real cause of scientific progress. Amid the general development of the sciences, transfusion has come up once more, transformed and widened; it will not satisfy the extravagant hopes indulged at first, but it will throw a broad light on the problem of health and disease. The principles on which this grand experience now rests are well settled—the functions of the blood have been clearly determined. We know that life dwells in every fragment of our being; the mass of nerves, the flesh of our muscles, the tissue of our glands, need the indispensable assistance of the blood, yet live by themselves. If general anatomy has followed out the work of Bichat, in studying the elements of dead Nature, physiology has realized Haller's conception, in analyzing the functions of these elements. Comparative study of animal and vegetable organization and the independent development of the tissues, after the evolution of the germ, has supplied general views upon the life of the parts; physiological dissection on the living animal, and particularly the mode in which poisons act, has completed the former results, and shown that each element in the organism has its individual activity. The experience of transfusion gains greater importance at this day, proportioned to the advanced state of science. Transfusion is not simply an operation practised on man; it finds its peculiar reason for existing as a process in scientific investigation. By it the properties of tissues and organs are analyzed, the independent life of the elements is once more made plain, and, when the secrets of the mechanism of our organization have thus been laid bare, transfusion is no longer an experimental remedy—it has become a process of reasoning.

At a time like our own, while the movement of minds is turning, with almost exclusive devotion, toward the justly-valued labors of Germany, it is not without interest to recall a course of discoveries peculiarly French. The history of transfusion in the nineteenth century, after the account of the fruitless efforts made in the seventeenth, has the advantage, besides, of allowing us to judge of the worth of methods by the nature of their results. These scientific triumphs of late date have hitherto been preserved only in special publications; but they are of too general an interest to be reserved for physiologists and physicians; they must enter into the wide domain of Science.

In the order of scientific facts a great discovery never remains isolated, but opens unknown horizons, and leads to useful applications, by the conquest of new principles. No one, nowadays, is ignorant that the labors of Ampère in electricity and magnetism created the telegraph. In Harvey's time, circulation was accepted, spite of protests by the faculty and the disciples of Galen; a genius like Descartes publishes it in his famous "Discourse on Method;" demonstration by experiment confirms the position of theory in every point; and the most important consequences immediately follow. They affect the knowledge of drugs and poisons, the anatomy of man, and the medical art that heals him. It was easily understood that medicinal and injurious substances will act more promptly if introduced directly into the vessels, and Fabricius, a doctor of Dantzic, infused purgative salts into the veins. Fracassati, a professor of anatomy at Pisa, injected alcohol, spirits of vitriol, oil of sulphur and of tartar. These experiments did not advance the healing art much, but they led to one important consequence, probably unlooked for by their authors: they were the commencement of a process which allows us to study the nature of poisons; and the history of poisoning afterward took a new direction.

To the physician and the anatomist the process of transfusion was directly and immediately useful. A century earlier, the illustrious Andreas Vesalius had created human anatomy; after the publication of Harvey's works, the arteries and veins were studied in preference. In the class-room where dissections are going on, it is out of the question to transfuse living blood; but, for the advantage of following the course and distribution of the vessels, it is useful to inject them with such colored matters as will solidify. The Dutch Frederic Ruysch is the leader in this advance. In the land of Rembrandt the art of harmonizing colors aims not merely to bring the human countenance to life again on canvas; the anatomist of Leyden so well understands the secret of injections that, by imparting color to the interior of the tissues, he will restore the semblance of life to inanimate bodies; when, near the end of his long career, Ruysch put to press in Amsterdam the remarkable book in which he describes the wonders of the anatomical museum of his native town, like an artist content with the perfection of his work, he exclaims, at the first page, "I have babies there that have been embalmed for twenty years; they are so rosy and fresh that you would say they are not dead, but asleep."

Ruysch's anatomical preparations, of which the secret is now lost, were contemporary with that marvellous experience, also founded on the discovery of Harvey—we mean transfusion of actual blood. About 1660 the notions in medicine of the ancients were strongly and persistently maintained, the blood more than ever believed to be the principle of life, and, with the knowledge of its circulation in the organism, comes the suggestion "to transfer blood from a young to an old person, from a healthy to a sick one, from cold to warm, from bold to timid people, from tamed to wild animals." But Galen's words are fully accepted; the theory of "animal spirits" rules unquestioned, and Descartes has given the system new vigor. That philosopher holds that there are in us two things—the spiritual life, comprising the soul, and the material life, formed by spirits, which he ingeniously compares to the restless particles of a wavering flame An unknown disciple of the great master, De Gurue, maintains the ideas of the new school in speaking of the transfusion of blood. "The blood of animals," he says, "containing a great quantity of spirits, cannot be mingled with that in the body of another animal of the same kind without fermentation, and cannot ferment without causing fever." For some persons, as Martin de la Martiniére, the transfusion of blood is a barbarism, and those who practise it are "butchers and cannibals." Others think of it, with Eutyphronis, that it errs by oversetting traditions. This "practice," he says, "cannot be allowed, short of altering all ancient medicine." The partisans of bleeding, disciples of Guy Patin, thought that transfusion of blood would overwhelm the patient, and increase what should be taken away from him. The eclectics, in fine, believe that this operation brings its supporters and its opponents into agreement: the first, because it carries off corrupt blood; and the last, because, by the supply of new blood in place of that removed, the strength of the patient is not lessened.

All these theoretical discussions might have continued forever, had not Dr. Denis cut them short in 1667. He looks for the solution of most questions in physics by experience, not by argument. Zeno affirms that every thing in the world is immovable. Diogenes walks for his only answer. Denis allows no other rule of action; he will not lose time in refuting the reasons of those who have written against the operation, but will oppose them by experience alone. The first two transfusions successfully practised on man are recorded in "a letter written to M. de Montmor, privy councillor to the king, and chief master of requests, by J. Denis, doctor of medicine, professor of philosophy and the mathematics." It is worth while to introduce, in few words, the eminent man to whom this work was addressed. M. de Montmor, a member and one of the founders of the French Academy, lived in the centre of scientific movement. Gassendi honored him with his friendship, and when that learned philosopher died, after many personal labors in the most varied branches of knowledge, De Montmor published a complete edition of his works. In the years preceding and following the foundation of the Academy of Sciences, before and after 1666, his house was a centre at which physicists and savants gathered every week to discuss the interesting questions of the day, and the society thus formed had its rules intended to aid the progress of science. A few years before, a Benedictine monk, Robert des Gabets, had preached a sermon there on transfusion of the blood. The king's councillor took interest in a discovery of which he foresaw the range, and gave the new experimenter the support of his influence.

"The first trial," Denis says, "was made on a young man, fifteen or sixteen years old. This youth was attacked by a slow fever, for which the doctors had bled him twenty times. He had become dull and sleepy, from the treatment, to the point of stupidity. Some little warmth was felt during the operation. Eight ounces of blood were taken from him, and arterial blood from the carotid of a lamb was immediately introduced by the same opening. He got up about ten o'clock, dined with excellent appetite, and went to sleep at four in the afternoon. He bled slightly from the nose."

This operation having succeeded, Denis tried a second, but more from curiosity than necessity this time. The author relates it himself as concisely as before. "The transfusion was effected upon a chair-porter, of vigorous constitution, forty-five years old. Ten ounces of blood were taken from him, and lamb's blood substituted. The man complained of no pain during the operation, and was delighted beyond measure with the new invention, which seemed to him very ingenious. When it was all over, he declared that he never felt better. Employment offering about noon, he carried a sedan as usual for the rest of the day. Next day he begged that no one but himself might be taken as the subject of new experiments."

Three years before, transfusion of blood had been practised by Lower in England, but only on dogs. Denis repeated with these animals the experiments he had made on men. These were varied in the most interesting ways. He not only transfused the blood of one animal into the veins of another; but, from the 8th to the 14th of March, in 1667, he caused the same blood to pass into three different dogs successively. Granting the correctness of the views then prevalent, he then realized the famous Pythagorean fable of the transmigration of souls. The experimenter was also bent on making his discoveries generally known, proposing to make trials in public, and, for this purpose, he fixed for the first day of his lectures "Saturday, the 19th of March, of the same year, at two in the afternoon, on the quay of the Augustins." History does not inform us whether Denis carried out his plan; but the Journal des Savants gives a tedious account of a controversy that broke out more fiercely. In this previous war of ideas, facts are neglected and forgotten, arguments are only dealt with, and they control opinions. Denis declared at the outset that he would depend solely on experiment; but, at the same time, with a contradiction explained by the tendencies of the times, he comes forth into the scientific arena with the usual weapons—he discusses. The works devoted to this warm contest are all inserted in the Journal des Savants; and such pages, long ago forgotten, show into what extravagances the fancies of the so-called scientific mind may be betrayed. Reading them, we involuntarily repeat the poet's line:

"The learned fool outfools the fool untrained."

The absurd was carried to its farthest limits in the arguments of a master of arts of the Paris University, named G. Lamy. "Since the blood of a calf," he says, "is made up of many different particles fitted to nourish the different parts of the body, if this blood is thrown into a man's veins, what will become of the particles of blood intended by Nature to produce horns? The case is not like that of a calf's flesh used for food, because those particles that are unfit for man's nourishment are altered in the stomach by coction. In the next place, since the mind and habits usually follow the bodily temperament, there is danger lest the blood of a calf, transfused into a man's veins, may give him also the stupidity and brutal dispositions of that animal."

Lamy finds followers among the opponents of circulation, his argumentative deductions are connected and consequent, but his starting-point is arbitrary and wrong. It is true his adversaries' reasoning is to blame for the same fault, but it will be accepted, if for nothing else, because it is addressed to those innovators who follow Harvey. A fragment of one of Denis's letters, on the question of the transfusion of blood, is worth quoting: "In the practice of this operation we only copy Nature, which, for the support of the embryo, makes a constant transfusion of the mother's blood into the child through the umbilical cord. Applying transfusion is only feeding one's self in a shorter way than usual; that is, it is putting ready-made blood into the veins instead of taking aliment that will turn into blood after several changes. The blood of animals is better for men than men's own blood; the reason is, that men, being agitated by various passions, and irregular in the way of living, must have more impure blood than beasts, which are less subject to such disorders. Corrupted blood is never found in animals' veins, while some corruption is always noticed in men's blood, how healthy soever they may be, and even in that of little children, because, having been fed with their mother's blood and milk, they have sucked in corruption with their nourishment."

All these quotations are curious, though they express mere obsolete ideas, because they show how far from the mark scientific discussions may wander, if they rest only on argument. Once started on that road, transfusion of the blood could run no long career. It yielded in a singular way. An isolated fact was enough to cause its fall. One of Dr. Denis's patients went mad after undergoing the operation of transfusion. His adversaries seized this accident as a weapon, and, Denis not having a diploma from the University of Paris, they procured a condemnation of the new doctrine. Transfusion suffers the same fate as antimony, a century later. On the petition of the Faculty after decision by the Parliament, Du Châtelet, the deputy prosecutor, publishes an edict proscribing it in the name of the law. What was the real cause of the downfall of the system? That it rested on mistaken physiological ideas. The blood was still regarded as the sole principle of instinct, intellect, and life. The physician who practised transfusion could only defend it by hypotheses, and justify its employment by explanations and reasonings. The labors of our own time alone can give it lasting life; transfusion will revive two hundred years later to a new and vigorous existence, for it will rest on the best-established truths of physiology.

The light thrown by Harvey upon the knowledge of life did not give a complete account of the mechanism of our organization; the opening of an era of progress by grand discoveries awaited the coming of Lavoisier, at the close of the last century. General physiology was founded at that period, and the office and functions of the blood were soon learned by degrees and clearly settled. Between 1815 and 1830 the history of transfusion passes into a new phase. Atwood, Blundell, and Diffenbach, make it generally known by important works. In France two eminent savants, Prevost and Dumas, devote themselves to new researches, of which the "Annals of Chemistry," for 1821, preserve the record; but the transfusion of blood has made decisive steps only within the last twenty years, due particularly to the labors of a modern physiologist, Brown-Séquard. We shall sketch the bold and interesting experiments he employed in attacking and dealing so successfully with the most difficult problems of life; the history of physiology hardly presents a more exciting and instructive page. For its full comprehension, the nature and functions of the blood must first be explained.

As it circulates within the vessels, the blood is to be regarded as a fluid in which an innumerable quantity of colored corpuscles are floating. On account of their shape, these little bodies are called globules, and they are invisible without the aid of magnifiers; in fact, their diameter scarcely exceeds two ten-thousandths of an inch. The vehicle of these globules has the scientific name of plasma; the matters elaborated by the digestive apparatus, and the products of decomposition of the tissues, are the essential components of this liquid; albuminoid substances, analogous to white of egg, fats, sugars, salts of a mineral nature, appear in it under different forms, and constantly repair it; while the excretory ducts as constantly carry off from it those particles that become useless to life. The elements of our tissues have their nutrition kept up by a constant movement of supply and withdrawal, new molecules replace the old ones, and acts of assimilation and disassimilation find by turns in the plasma their point of origin and completion. The blood-globule is nourished just as the constituent parts of the glands, the muscles, the nerves, and the brain are, and the only difference to be noted in this respect is that the process takes place within the very plasma itself, while the other elements are parted from it by the thin membrane of the capillary vessels. The globule has so distinct an existence of its own, that the chemical principles composing it are not found in its plasmatic medium. The various reactions shown by these little bodies in presence of chemical agents lead to the belief that they are found in the plasma in all stages of their development; their dimensions are not the same at the different ages of our organization. When the human germ is in process of evolution, the first lineaments of the vessels are traced in the depths of the tissues, and the heart begins to beat; the sanguine fluid is then formed, but the globules it contains are much larger than they will be after birth and in adult age. During this embryonic life the newly-formed blood does not communicate with the vessels in the maternal system—the two circulations being juxtaposed, but independent; there is not, as the belief in the seventeenth century was, a natural transfusion of the mother's blood into that of the embryo, because the solid particles or globules of each circulate and remain in each of unequal size. The study of the blood-elements in the animal series is interesting; they are found larger in fish and reptiles than in birds and mammals, whose vital activity depends on other powers. In spite of the resemblances presented by the sanguine fluid in these different groups, the blood of a fish could not vivify the body of a reptile for any length of time, nor could a bird's blood be substituted for a mammal's. The animal species whose nutritive fluid is mutually transfused must be closely related as regards natural classification: the globule which emigrates into a foreign medium can only become acclimated there in so far as its conditions of existence are not profoundly modified.

The blood-globule not only lives its individual life within the plasma, but it needs, in order to complete its function of vivifying every part of the body, to absorb oxygen from the air, and it then takes that bright vermilion color which is characteristic. The phenomenon of that new coloring is an essentially vital act, a chemical reaction taking place between two bodies, one solid, the other gaseous. Precisely the same thing happens with the commonest copper coin placed in contact with the air it absorbs a gas, and its surface is soon covered by a colored product. In the lower animals that have copper in their blood, the vine parasite, for instance, the globules take a bluish color on contact with air. The same phenomenon is remarked in the vegetable kingdom; indigo, which is white in the plant, turns blue when exposed to the air, and many coloring substances are formed in the same way. The red globule contains iron, and the chemical action taking place in it may perhaps be compared to the formation of rust. Exposed to atmospheric air, it takes a dark-red color, while continuing crimson in the arteries. Deep in the tissues, the oxygen of the globule is disengaged; combustion occurs with production of heat, but without flame, as is the case with starch; the blood becomes venous and darkish; then, sent back to the vessels of the lungs, it resumes its arterial coloring with the vital air.

In connection with the history of transfusion it is important to know the quantity of blood contained in the organism; this has been estimated, by approximation, and attempts have been made to ascertain it in the human subject. A criminal named Langguht was beheaded at Munich, July 7, 1855: about eleven pounds of blood were collected by Professor Bischoff. The weight of the body was one hundred and forty pounds; the proportion of blood being one thirteenth. This estimate has been accepted by many physiologists, although some believe it is too low. Nothing certain can be arrived at on the subject; does not the quantity of blood in our bodies vary according to very many conditions? It does not remain the same before and after eating, while asleep and while awake. In hibernating animals, as the marmot, or the dormouse, if the weight of the body decreases one-fourth in the period of rest, that of the blood is considerably reduced. The same fact is observed in fasting, the globules losing size and color. Disease produces a similar result, and nothing is more correct than the commonly-held opinion that "grief and privation consume the blood." The precise ideas we now have of the nature of this fluid have largely corrected Broussais's errors, and more than one practitioner in our day would assent to Galen's precept, that "in bleeding the measure of a half-pint must not be exceeded, and in any case the veins of a patient under fourteen must be spared." The study of transfusion proves the importance of the sanguine fluid better than any general considerations. We shall presently point out those well-settled cases in which the physician may practise the operation; but the reader is now prepared to understand how each part of the body derives supplies of life from contact with this fluid. The functions of the tissues will be briefly analyzed in turn; glands, muscles, nerves, spinal marrow, brain, will display their special activity. We shall see how the blood-globules feed singly all these flames, which blend and mingle to light the torch of life.

Secretion takes place by means of the glandular tissue. This function is connected with nutrition, and in the lower products of organized matter is identical with it. The simplest vegetables, and the lowest animals, are instances of this blending. In the higher degrees of animated beings, the elements of secretion separate and maintain their own life, finding in the surrounding air or the moistening fluids the conditions of their nourishment and work. In perfect organizations the glandular tissue becomes more complex, receiving nerves and vessels; natural transfusion of the blood begins to play an important part. The size and secreting energy of the glands are directly related to the quantity of blood passing through them; thus the kidneys, incessantly at work, have a highly-developed arterial system. The blood is renewed in the glands as in all the tissues, and the dilatable walls of the vessels admit it in different proportions, according to the state of rest or activity of the organ. In this case, as in all others, particular facts are merely the expression of a more general law. The flow of blood increases when a stimulant exerts its action. When a glandular element acts with energy, it produces a high degree of fulness of blood in all the neighboring parts; and physiologists have thoroughly proved this fact in the case of the salivary glands of animals. In a state of rest, the congestion of these glands is slight, the blood dark in the veins issuing from them; the organ is then gaining growth. When the animal taken for experiment emits saliva under the influence of artificial stimulus, the glands, on the contrary, fill with blood, the vessels grow turgid, and take a high vermilion color. Thus variations in the supply of blood always correspond with degrees in secreting activity, and secretion ceases when the blood no longer comes to the glands. If the vessels of the liver are obliterated, bile ceases to be formed; if the arteries of the kidneys are compressed, secretion by those organs stops. The statement of the conditions of the problem suffices to suggest its solution; the blood is a medium whence the glands draw the principles of their growth and functions; the circulation of the sanguine fluid within the glandular tissue is a true transfusion kept up incessantly by the heart, and which only artificial transfusion can be a substitute for.

Nutrition and secretion by their constant work keep up the organized state of vegetable and animal matter. Plants possess only these two functions, and we may almost say the same thing as to animals while asleep; but these are not the only functions assigned to the waking animal, which comes into relations with the external world, through motion, sensibility, and intelligence. The muscular fibre, the special organ of motion, has its activity, independent of the nervous system; local transfusion confirms this scientific view, which now rests on manifold proofs. Like the secreting element, the muscular fibre is distinct in some lower animals; the microscope detects it in that state in the transparent body of the infusoria called vorticelli. In the higher degrees of the animal series this fibre is found in connection with nerves and vessels, and, though it enjoys an excitability peculiar to itself, it receives an impulse to movement from the motor nerve. The contact of the muscular fibre with blood-vessels is very close; but the chemical composition of the blood that moistens it varies according to the quantity of work yielded; thus it is indispensable that new fluid should be constantly transfused into the network of veins in the muscle. If the motor fibre is at rest, the blood passing through it is scarcely modified. If it is in a state of half contraction, the oxygen decreases in the blood, and the carbonic acid increases. If contraction is evident and powerful, combustion and production of carbonic acid are then at their maximum; the blood of the veins is extremely dark—the muscle is growing and acting both at once.

These are modifications which the muscular fibre undergoes during life. When death occurs and the blood is no longer renewed, muscular irritability disappears after a time which varies, and in an order which is fixed. The left ventricle of the heart first ceases to be excitable, then the intestine, the bladder, the iris, the muscles of animal life; the right auricle of the heart dies last; it is the ultimum moriens. The organic matter making up what is called the flesh decomposes, and is thenceforth governed entirely by chemical forces. The juices it contains become acid, coagulations take place, and then comes on the condition called by the name of corpse-like rigidity. Thus changed, the muscle is no longer excitable; but, if it is subjected at this instant to a current of arterial blood, it immediately revives, rigidity disappears, the muscle-fluids regain their former composition, and the individual activity of the fibre displays itself anew. Experiments establishing this great fact have been tried, not only on animals, but also on man even, and under circumstances that present some difficulty in the recital; the dramatic side of the subject is vivid enough to allow of a strictly scientific narration by itself. We will relate the transfusions performed by Brown-Séquard on two persons beheaded at Paris in June and July, 1851.

The first experiment was tried on a man aged twenty. He was beheaded at eight o'clock in the morning; eleven hours later all trace of irritability had disappeared from most of the muscles of the body. Injection into the muscles was begun at ten minutes past nine in the evening; the quantity of blood (which the operator took from his own veins) was enough for a limited part of the body; he therefore confined his experiment to the hand. Injection was made by the artery in which the pulse is usually sought, a little above the wrist, and, of course, in the direction of the fingers; it was urged at first quite fast, then slowly. The blood which went in bright colored, passed out dark from the vein, as is the case in life. The operation continued thirty-five minutes, and, ten minutes after that time, irritability had returned; a movement in the muscles of the hand could be artificially excited.

With the second subject, injection of the blood of a healthy dog was made; the blood had been first deprived of its coagulable matter, and beaten up in the air; there was about a pound of it. The subject was a strong man, forty years old. Death had occurred at eight o'clock in the morning; at twenty-five minutes past ten in the evening rigidity was complete, without a trace of contractility under the influence of stimulus. The arm was amputated, and at twenty minutes past eleven Brown-Séquard effected injection by the brachial artery. The skin at first took a livid color, but very soon the roots of the hair grew erect, giving the effect of goose-flesh, as it is called. This artifical circulation was so entirely successful that the veins on the back of the hand presented a bluish tinge; a heating like that of the pulse lifted the main artery of the wrist, muscular life revived; the fingers soon lost their stiffness, and at forty-five minutes after eleven irritability had reappeared in the muscles of the arm; it was still perceptible at four in the morning of the next day.

Experiment has never more clearly proved that the blood is essential to muscular life. In the limbs of these subjects the organic matter was decomposed, and all vital manifestation had become impossible. A flow of blood throughout them was effected, and at once this muscular flesh becomes contractile again; the special activity of the motor fibre is reanimated, and its functions performed as in life. It will, of course, be objected that the muscular element receives its conditions of activity from the motor nerves, and that the blood-globules only vivified it indirectly, by restoring excitability to the nerves; but has not the mode of action of curare proved that the life of the muscle persisted after the physiological death of the nerve? If the arteries of the lower limbs of a living animal are tightened by a compress, the withdrawal of the blood will in the same way cause the properties of the nerves to disappear before those of the muscles; an artificial stimulus, directly applied to the muscular fibre, will still produce movement, after nervous excitability has ceased to exist. If you then remove the compress, you set the flow of the blood free, and the peculiar action of the motor nerves is completely restored. Thus the life of the nervous element itself has been successively extinguished and revived; after that the inciting stimulus from the train of the spinal marrow may be transmitted through the medium of this conductor, which possesses a real autonomy.

The nerves of general sensation, like the nerves of motion, demand the contact of arterial blood. The anatomical distribution of these nerve-elements does not allow the action of the sanguine fluid upon them to be studied as to their surfaces; yet sensation constitutes too well-defined a function not to be the object of experimental analysis, as motion is; this analysis is made by the help of transfusion upon the spinal marrow, the organ that receives all impressions made on the skin. Physiologists have used an ingenious process to prevent the blood from moistening this nervous centre: they inject a liquid filled with an inert powder into the vessels, in a uniform direction; the capillary parts of the circulation are soon clogged, the spinal marrow ceases to be in relations with the blood, and ceases at once to receive impressions from the skin. The same phenomenon is observed when all the blood-vessels that go from the main artery of the body to this nervous centre are artificially destroyed; the return of sensation takes place only when arterial blood is restored to the spinal cord. This fact is also proved by the transfusion of new blood into the veins of an animal that has yielded to a hæmorrhage. Again, another experiment, made in the following way, furnishes a proof of it. Two dogs were submitted to the section of the nervous centre which contains the vital knot, occasioning death. The appearance of death was produced as soon as the starting-point of the respiratory nerves was deeply injured. By slow degrees the nervous tissues lose their properties, and, before they are entirely extinct, the spinal cords of the two animals are exposed. One is subjected to the action of oxygen gas, and its sensibility increases; the other is influenced by hydrogen gas, and its sensibility remains unchanged. These facts show with absolute certainty that the nervous centres find their conditions of activity in the oxygen of the blood, or, to speak more precisely, the oxygen of the blood-globule.

The brain, the organ of the highest manifestations of life, performs its action like the spinal cord, and an elaborate network of blood-vessels distributes the nutritive fluid throughout all its parts. Yet the mass of the brain does not keep its functional activity constantly at work. The whole organism rests after the day's labor; the brain, when not waking, preserves only its life of nutrition; therefore the religions of ancient Greece, not without reason, regarded Sleep as the brother of Death. The quantity of blood transfused into that organ during these two conditions, so different, of sleep and wakefulness, is not the same. Dr. Pierquin had the opportunity of making observations upon a woman in whom disease had destroyed a large part of the bones of the skull, and deprived the brain of its membranous covering; the nerve-mass, quite exposed, shone with that brilliant lustre observed in all living tissue. While at rest in sleep, the substance of the brain was pink, almost pale; it was depressed, not protruding beyond its bony case. At once, when all the organs were quiet, the patient uttered a few words in a low voice; she was dreaming, and in a few seconds the appearance of the brain completely changed; the nerve-mass was lifted, and prominent externally; the blood-vessels, grown turgid, were doubled in size; the whitish tinge no longer prevails; the eye sees an intensely red surface. The tide of blood increases or lessens in its flow, according to the vividness of the dream. When the whole organism returns to quiet, the lively colors of the infused blood fade away by degrees, and the former paleness of the organ is observed again. The succession of these phenomena permitted the conclusion that increasing action of the cerebral cells attracts a considerable quantity of blood to them.

The general circulation in the brain is weak during sleep; in fainting it suffers complete suppression, and every one must have noticed the effects that result in this organ from the abstraction of blood. The least emotion, the smell of a flower, can bring on impressions that react on the heart, and for a moment suspend its movements; the blood then ceases to stimulate the brain, and paleness of the face indicates the bloodlessness of the deeper parts. The organism no longer puts forth that outward activity which is peculiar to life; it droops, no intellectual manifestations occur, no impressions from light or sound are felt; but let a current of cool, fresh air touch the face, and life revives, the heart resumes it movements, color comes to the cheeks, and the phenomena of intellect and sensation reappear in the inverse order of their cessation. The English surgeon, Astley Cooper, produced similar phenomena in dogs by compressing the arteries of the brain at the neck; the animal fell into utter insensibility, and seemed to die. On suspending compression, cerebral life immediately returned; yet this was but an imperfect representation of what takes place in fainting. It was reserved for one of our own physiologists to go more deeply into the mechanism of the phenomenon. To bring life back again for a moment to a head severed from the body, and to restore it by the arterial blood, this was the problem which Brown-Séquard proposed and solved. The details of this memorable experiment were these: A dog is beheaded, and the head, still warm, separated from the trunk at the junction between the neck and chest. The evidences of life disappear by degrees, the eye losing its expression last. An electric current sent through the remaining part of the spinal cord no longer excites any contractions, the respiratory movements of the nostrils and lips cease entirely. After ten minutes have elapsed, Brown-Séquard adjusts to the four arteries of the head an arrangement of tubes communicating with blood deprived of its coagulable part, and charged with oxygen. By the help of artificial mechanism, imitating the action of the heart, the experimenter makes the blood circulate throughout the brain and spinal cord. A very few moments pass before irregular quiverings give life to the face, growing more decided, and at length movements reappear in all the muscles, and the eyes resume motion. "All these movements," says Brown-Séquard, "seem directed by the will." The experiment was continued for a quarter of an hour, and during all that time the vital manifestations and the appearance of their being voluntary continued. They soon ceased after the injection was stopped, and then followed the group of phenomena observed in dying, the pupil contracted and again dilated, and the last effort of life was a strong convulsion of all the facial muscles.

The naturalist experiences the strongest emotions at the sight of so extraordinary a spectacle. The physician now understands the necessity of contact between arterialized blood and the matter of the brain. He knows why a reclining position is proper in cases of fainting, giving easy access for the vivifying fluid to the brain. He knows that by throwing water on the face he will act upon the nervous centres, reanimate the movements of the heart, and cause circulation of blood in the mass of the brain. The philosopher asks himself one of those questions which are as old as the world, and more than ever of present interest, since the animated discussions of Barthez and Gabanis: Does or does not organized matter engender the phenomena which it manifests? A grave problem, which Claude Bernard, in his admirable "Report on the Progress of Physiology," seems to us to have solved. That savant holds that the brain of the animal subjected to the experiment of transfusion of the blood acts like a complicated piece of mechanism upon the restoration of the blood belonging to it: the cerebral organ is only the instrument of the intellect, and the human machine marks life, as a clock marks time.

A physiological dissection, like that which transfusion of blood may be said, in some sort, to perform upon the glandular, nervous, and muscular systems, how complete soever it may be, has no value, unless the results of the analysis are combined; the experimental cutting up of the human body ought to end by recomposing the whole of it. That is the mode of procedure in the physical sciences. The colorless beam of white light is separated through the prism as it is by the drops of water that form the rainbow, and after passing through the glass it spreads into a wonderful gathering of colored rays. Each ray is studied in its properties, calorific, chemic, or luminous; then, when the work of analysis is ended, another prism directs all these rays in an inverse course toward convergence and the beam of colorless light is reformed. It is so with the organism and its constituent parts. The individual life of the glands, the muscles, the nerves, the brain, is demonstrated by the aid of local transfusion, and the synthesis of the living being is accomplished at once by general transfusion. The blood coming from the heart is distributed into all parts of the body, no longer confined by art in a fixed space; thus the partial lives of the tissues and organs are simultaneously renewed, and the life of the individual becomes an admirable collective unity.

These important results, which the physiologist regards from the high point of view of theory, the physician meets on practical ground and in his patient's presence. And clinical triumphs have confirmed scientific views, which find their reasonable explanation partly in our knowledge of the normal life of the elements, partly in the morbid changes they are subject to. Transfusion of blood has sometimes served as an heroic remedy for arterial hæmorrhages, and losses of blood occurring after confinement. In these situations there is no injury to the elements of the nervous tissues, the glands and muscles; thus the supply of new blood restores life to them; it is replenishing a lamp, with its machinery all in order. When, on the contrary, the glands, muscles, and nerves, are changed in the first place, and the injury to the blood is the consequence of alteration in the tissues, instead of being its cause, transfusion cannot be as serviceable; it is almost always powerless; and, to repeat our comparison, the process is like pouring oil into a lamp more or less out of order in its inner construction.

Transfusion is not only employed to replace blood lost by a patient, but used also to substitute pure for vitiated blood. It is successfully applied to resist poisoning by carbonic oxide. This gas, formed by the combustion of charcoal and the oxygen of air, is a powerful poison. Breathed in moderate quantity, it induces death by well-defined action; the carbonic oxide, acting on the blood-globules, displaces their oxygen, and forms a stable combination with them, which is inert as regards vital properties. The constituent elements of the organs soon cease to act, and they die as they do after arterial hæmorrhage. For some hours, immediately after the poisoning, the blood-globules only are concerned, the other tissues remaining untouched; it will be enough, then, to restore a healthy state, to empty the vascular system, and replace the poisoned blood by new blood, and life will revive. Thus the history of transfusion once more proves that triumphs in the healing art may find their starting-point in the physiologist's table, as advances in industrial art often originate in the chemist's alembic.

In the centuries regarded as a whole, the epoch of Harvey and our own seem to belong to a similar period. The demonstration by physiology of the individual life of the parts, and the practical applications of transfusion, are wholly modern, as the circulation of the blood itself is. In ancient days the general belief was, that the life dwells in the blood, and yet some ancients seem to have had a suspicion that the elements of the organization live of themselves, and that, perhaps, the blood has a movement of circulation. Yet the ancients observed the life of the parts only in their outward forms. It is as a child studies the works of a watch: give it to him, and he is satisfied to hear it tick; open it, and he follows with his eye the movement of the wheels, but does not go further than to note appearances. Progress comes with age, and the child, seeing the same watch when he is a grown man, asks why and how it goes; taught by experience, by dint of perseverance and labor, he takes off and replaces every wheel, gains a precise idea of the mechanism of each part, and the arrangement of the whole is then clearly understood. Men of science in our times have studied the human machine so: the life of the parts has not only been observed, but traced and detected in its most secret machinery. Transfusion of blood, so useful in this respect, never acquired any true scientific importance in the seventeenth century. At first it appears as a universal panacea, aiming at the mastery of life, and triumph over disease itself. We have seen how the mere imaginings of that idle dream passed away. In our day the true method, the method of observation, is rightly honored, and scientific questions, no longer agitated with mere parade of eloquence, are modestly studied by their facts in the seclusion of laboratories. Transfusion again comes up, but not with its old extravagant pretensions; it no longer aspires to give universal, indefinite life. Reduced to the simple duty of a scientific process, it unveils the most mysterious secrets of the organization; it throws light upon the life of the parts; it demonstrates that each element in the organism lives of itself, and finds in the blood the conditions required for its action.—Revue des Deux Mondes.