On Mechanical Tremulation, Vibration in the Body
By Emanuel Swedenborg (1719)
EMANUEL SWEDENBORG'S treatise, "on Tremulation," which now for the first time appears in the English tongue, was originally written toward the close of the year 1719, as may appear from the following statement in a letter by the author, dated Nov. 3, 1719, and addressed to his brother-in-law, Dr. Eric Benzelius, then librarian of the University of Upsala:
From the contemporary entries in the Proceedings of the Sundhets Collegium, or Board of Health, in Stockholm, it appears that this work of Swedenborg's was duly received and reported, the Board resolving that the treatise should be read in turn by all the members, who afterwards were to pronounce an opinion respecting it. While thus circulating, it seems that the manuscript disappeared, as there is no further reference to it in the Proceedings of the Board, and as it has not been preserved in the library of the Royal College of Medicine at Stockholm. Swedenborg himself retained only the first rough draft, which has also disappeared, but from it he made a second copy of chapters I.--VI., and XIII., which fortunately has been preserved. This, therefore is all that remains of the original work, "On Tremulation," and it is from this copy that we have prepared the present translation.
A few quotations from Swedenborg's correspondence with Benzelius will give the history of this second copy, and also illustrate the nature of the work itself:
This is the last reference made by Swedenborg to his little work, "On tremulation." The desired opportunity did not offer itself, and Benzelius, consequently, never received any further installment of the work. The copy of chapters I. VI., and XIII., was subsequently carried to the city of Linkoping, when Benzelius, in 1731, was appointed Bishop over that diocese, and there it remains until the present day among his other papers, which are preserved in the library of the cathedral. Dr. R. L. Tafel, in 1869, procured a photo-lithographic copy of the manuscript, which constitutes pages 1321 80 of the first volume of Swedenborg's photo-lithographed manuscripts.
As indicated by the author, this copy was transcribed from the first rough draft, which will account for certain unpolished sentences and other crudities of diction, many of which will be apparent also to the English reader. The original language is very peculiar, indeed, both as to orthography, syntax, and vocabulary. The Swedish of the early part of the eighteenth century was as different from modern Swedish, as was the language of Tyndale or Coverdale from modern English. Swedenborg himself was, in fact, one of the first who ventured to employ Swedish in a scientific treatise, and he was therefore forced to coin many new and strange expressions, and to borrow largely from other tongues, such as the Latin, French, German, and even English, with which the original of this work is plentifully besprinkled. The author himself soon recognized the insufficiency of the Swedish, as then existing, as the vehicle of scientific thought, and therefore, in all his subsequent works, he fell back upon the all dominant Latin.
Leaving to the reader to judge of the intrinsic value of the present treatise, we will merely point out its historical importance as a contribution toward a correct understanding of the growth of Swedenborg's mind, and of the beginnings of those great principles of natural truth which received a more perfect development in his later scientific and philosophical works. It is to be noted that this treatise was written when the author was but thirty-one years of age, and that it is the first of all his anatomical or rather physiological works. It may be regarded as distinctly marking the close of the first period of Swedenborg's career as an author and scientist. During this period, which commenced in the year 1709, he had written no less than twenty different treatises, nearly all in the Swedish language. Some of these were published by himself, and all have been preserved in one form or other, but none of them has as yet appeared in English. All may not be of supreme value, regarded in themselves, but they are nevertheless indispensable to a thorough comprehension of Swedenborg's preparation for that unique and stupendous mission which awaited him. Beginning his literary career as an annotator of the classics, he next appears as a Latin poet of no mean ability. Forsaking Polyhymnia for sterner muses, he now delves into mineralogy, geology, astronomy, mathematics, and physics, Writing numerous interesting and.suggestive little works on all these subjects, while at the same time publishing his Deedless Hyperboreus or Journal of Mathematics, Mechanics, and other physical sciences. In the sixth and last number of this journal, which was written in the beginning, of 1707, but not printed until October, 1718, we find an article on the subject of tremulation, which we have added as an introduction to the present treatise, being the conception and forerunner of this more extended work, which may be looked upon as the last work of Swedenborg's youth.
He now appears to have begun his studies and labors over again, as it were, in a more thorough and systematic manner, and with more mature results. Leaving physiology for a time, he returns to metallurgical, geological, and astronomical subjects; he writes his "Lesser Principia" in I720, publishes his ('Chemistry " in 1721 his " Miscellaneous Observations on Minerals, Fire," etc., in I 722, and the " Principia," the " Regnum Subterraneum," and the "Outlines on the Infinite," in I 734. Having thus a second time run through the cycle of these more ultimate sciences, Swedenborg, in 1735, resumes his study of the human body, which he fitly terms is the temple of all the sciences." The great work, (& on the Brain," the "Economy of the Animal Kingdom," the "Rational Psychology," the "Organs of Generation," (X The Animal Kingdom," and others now follow one another in rapid succession, but through all of these magnificent works of philosophic science there vibrates the key-note which many years before was struck ill the work, "on Tremulation." Nay, even in Swedenborg's latest theological writings there will be found many traces of the principles and arguments first presented in this little treatise.
HUNTINGDON VALLEY, PA. February 15, 1899.
It is known that a membranous string is the best medium of sound, that is, of tremulation. By a membrane is meant anything most external or the surface of a solid substance, which surface receives the tremulation before it is received in the body itself, which consists of continuous membranes and surfaces; and this in the same ratio as that of the square to the cube.
If the string of a lute is touched, it will cause a vibration in the other strings which are tuned in the same key. An outside sound will often cause a vibration in a whole musical instrument, as also a whole gallery will vibrate from the sound in the pipe of an organ, that is, if they are in the same key or tune. A glass may break from its own sound.
THE SIXTH RULE.
The oscillating circles in the water are reflected according
to the angles of incidence. In a round vessel full of water they return to the center;
in an oblong channel they go forward and backward; a rope, hanging in a mining-shaft,
moves itself up and down in serpentine coils; the same takes place in a musical
chord; an echo propels the sound forward and backward; thus also does the substance
of the sun move the particles of our sight.
THE NINTH RULE.
In tremulations there are millions of variations.
How many different sounds are not produced by a well-tuned piano? how many are not still lacking within an octave ? One sound is different from the other, is more flowing, broader, duller, or harsher. The sound and pronunciation of men differ like their faces. Every vowel has its own separate sound. If these variations are duplicated, it will be seen that there are millions of different kinds of tremulations.
From the above rules it can be shown that our mobile life sensation, or our nature, consists in little vibrations, that is, tremulations. From the first rule it may be seen that a most minute particle is able to communicate its motion to all other things in the whole body, is able to bring a certain membrane and sinew, the blood the life, and the/spirit into the same motion with itself, and thereby: all contiguous membranes, fibres, and nerves. Speech is nothing but tremulation, like the sound in a strinHearing is only a concentrated collection of such tremulations, flowing in through turbinated membranes, and propelling themselves over hammers and anvils up to the dura and pia mater, which are similarly vibrating; so that all fibres, nerves, animal spirits, and the blood, thus touched, will come into a motion according to the preceding rules. If the same tremulation is caught by the membrane by means of the sympathetic vibration of the teeth or the bones of the head, the sensation of hearing may be effected independently of the mechanism of the ear. Smelling and taste are similarly produced by contact with various kinds of particles round, angular, or sharpby which the fibres and nerves are pulled or drawn, carrying the tremulations to the aura and pia mater. Similarly with the Sight, which is the most delicate of our senses; the least of color or light strikes against the minute fibres, and the distended optic nerves communicate it to the coats of the brain, effecting sensation and tremulation round about. It is the same with the motions of the temper, which are derived from a stinging or biting of the bile in the internal organ; similarly in the case of all external feelings or sensations, because all things are so connected by threads and sinews, that what is touched in one place is felt in another, and especially in the membrane of the brain, for all the threads and nerves terminate there, and into it is collected whatever belongs to the whole body; if, therefore, the tremulation is first felt in that membrane, it will at once find space and matter by means of which to communicate itself over the whole body. If now this membrane becomes slack, or is deprived of its heat, its blood, or its animal spirits, then the whole man becomes dull, heavy, and dead. Further, when a relaxation takes place in the nerves of the five senses, after having been in a state of tension during the entire day, then sleep sets in; and yet, during the sleep, we have something similar to sight and hearing, etc., which things go to prove that all the external senses are still kept in internal tremulations. It also frequently happens that a person falls into the thought of another person, that he perceives what another is doing and thinking, that is, that his membrane trembles from the tremulation of the other person's cerebral membranes, just as one string is affected by another, if they are tuned in the same key. It may not be presumptuous to conclude that the thoughts of the unreasoning animals are tremulations, proceeding from the internal and external sensations of the body and its senses; so that experience has' taught them what is meant by one kind of tremulation and what by another, just as we recognize the words, and their meanings by the different kind of tremulation in each sound. That no part of the body can be touched without communicating the touch to the dura and pia mater, that is, the membrane of the brain, and that nothing can be touched in this membrane, without communicating it to the whole bodymay be seen from all those threads which are joined to the sinews, outwardly; as also from those twenty to thirty nerves which terminate in the cerebral membrane, and which all are clothed by it. If said membrane is injured, a person is at once deprived of a sensation; he fails, swoons, loses his thought and his reason. If the fibres or nerves become slack, a person is similarly deprived of sensation, as takes place in colds, congestion of the blood, or in sleep. lf the animal spirits are overflowing, as in intoxication or in anger. then the membrane becomes too much heated and distended, so that it makes a manifold and wild tremulation instead of the proper and usual one. From all this it follows, that, by means of so many contacts or impressions, there is in us a continually moving, tremulatory, and living force, in the feasts as in the greatest, according to the preceding rules.
I. IF common sense be consulted and allowed to guide us as we inquire further and further into the real cause of life as to what it is that really makes us living and why generally consists- we must finally come to the conclusion that this cause is motion. for is it not according to common sense that everything that lives also moves, that is, that the living or the being is inseparable front the moving?
Life consists both of certain internal senses and of a number of external ones. No one can deny that the external senses owe their existence to motion, for there must be something in the atmosphere which flows in with certain little impulses and Circlings, moving about the finest fibbers and most minute termini, which by means of tremulation or little vibrations carry forward the notion to a certain sensation, and which thus by a motion distributed over an entire system Contribute or effect together a sylllbolum of life. Thus also with the internal senses: what thought is there, or what living recollection, in which motion does not effect as well the first impression as the last? In a word, if common sense is followed, we will inevitably find that Rest can never have any part in that which is called Life, for rest and life are two contrary things, just as a dead state and a living state. Experience testifies to this: as soon as the motion is obstructed by any obstacle, it is seen that life is at once deprived of a certain spark of its proper nature; but as soon as something more moving is added, it is seen that the liveliness is increased. This may best be seen from insects and other small animals, with whom life resides as it were in the least little drops of fluid: if the sun-ray strikes them, or touches their fibril, membrane, or little vein, then their whole life quickens at once and is as it were kindled, and the senses begin to live; but this motion, or this life, ceases as soon as the cold season arrives, for cold is the very opposite to motion; life with them is therefore mostly a motion. With the greater bodies the cold cannot effect so much, for it has less power to penetrate a great solid, as may be seen from geometry, so that we are not deprived of motion during winter, but still the principle is the same. Cold weather often causes what is most external to become dormant or extinguished; a person is chilled, or is deprived of a certain sensation, so that a loss of spirit, or a dead state is always the result when the motion is stopped by the cold. In a word, life consists in the motion but death in the rest of the particles.
Now in regard to the finer motions which cause that we live, that we have the use of our senses and our thoughts, and that we possess the complete harmony or communication of all these things as one, it should be remembered that these motions are of a more subtle essence than those which have been examined by the learned. The geometry of these motions is closed to us and to our coarser senses, so that we can hardly be said to have come further than to the first step of the knowledge concerning them, many thousand steps still remaining before we will be able to ascend to any perfect knowledge. For all that which makes the being of a sense, is more subtle than the sense itself and what ever is effected by that sense, so that it seems that only a finer sense is able to form a judgment concerning a grosser one, but the latter cannot form any judgment regarding itself. The ear, for instance, cannot possibly know or feel what it is that is vibrating in its organ, or how one thing is moving against another, unless a more subtle organ reveals it. The thought. which mostly is kept in attention to the feelings of the external senses and in their collective center, is not of itself aware of that which constitutes its own motion and life. In any case the conclusion must be this, that those motions in which life resides are the most subtle of all motions, of a nature such as cannot be seen or comprehended by any comparison with the grosser forms of motion.
2. Tremulation is the most subtle form of motion that exists in nature, and it possesses wonderful and distinctive properties, differing from all other motions. Although what is tremulatory presents itself each moment before us, playing round about each of the senses, yet is our mechanism and our reason still so little cultivated, that we have no proper knowledge of tremulation and its most subtle nature, as to wherein it consists, and wherein it differs from other motions. If tremulation is closely examined it will be found that it most closely resembles an axillary motion, as to its subtlety, or a motion within the least of space, that is, such a motion as takes place at the center alone; and that it has hardly anything in common with local motion, which takes place from one place to another. Tremulation, consequently, is not subjected to the laws that govern local motion. In a hard substance tremulation seems to be nothing but something swiftly moving top and down., an effort to recover the balance, like a ball thrown against the floor which makes smaller and smaller reboundings, until finally it returns out of the balance of motion into an equilibrium which is in a state of rest. It is the same with the most minute particles which possess hardly any weight and which of themselves move neither up nor down; if touched by the least motion these will leap and bound and tremble, until, after a period of tremulation, they finally return to their rest. Experience shows also that the lighter and more subtle the particles are, the swifter is the communication of the tremulation. Water trembles so slowly that the tremulation can be followed by our observation. Air moves more swiftly, and ether more swiftly still. Fire, or its radii, moves so swiftly that the tremulation is almost instantly communicated to us from the sun itself. It may be seen from this that the whole nature of tremulation consists in the effort of a thing to recover the balance which it was about to lose.
Tremulatory motion has in itself nothing in common with local motion, for it will be found that the latter requires its own fixed times, corresponding to its distances, adding to this, each movement, an increase in a certain measured ratio; it possesses a certain quality in a heavy substance and another in a light one, it is different in relation to a greater surface from what it is in relation to a smaller one; while on the other hand a tremulatory motion can exist in the same thing that is simultaneously subjected to local motion. A thing can be carried from one place to another, while at the same time it is trembling continuously without the least hindrance from the local motion. A bomb flying through the air, may in its course be subjected to tremulation; nay, one tremulatory motion may be within another one; a greater motion may exist together with a lesser one; within the latter there may be a still smaller one, and finally one most minute. Over an undulation, such as is seen in the water, there may be moving a smaller undulation or oscillation, over the latter a tremulation, over this a contremiscence, and so, finally, a most subtle one, which almost might be called a sensation or a vivum. A human body on board a ship may undulate up and down with the waves, while at the same time the brain possesses its own undulation; over this again there may be the vibration of a tremor, over this a tremulation, and over this a least trembling, such as produces the sense of hearing. The one motion may therefore be within and above the other, each without interfering with the other. The more a body is stretched out or expanded or in a state of quiescence, and the more fixed and heavy it is, the more does the tremulatory motion seem able to exhibit its proper nature; a whole mountain, entire houses and cities, with bells and belfries, tremble and shake from comparatively small causes, whence it may be seen that tremulatory motion has no consideration for what is heavy and great, but the greater and heavier a thing is, the more freedom does this motion possess to penetrate the whole and to bring everything into a sympathetic trembling, as shall be shown better in what follows.
3. As now living force is motion, and as life consists of little motions, and as the most subtle motions in nature are contremiscences, it follows that whatever lives in us consists of contremiscences, that is, most subtle motions; it is therefore our opinion that whatever lives in us is a tremulation in our finest nerves, in the most delicate membranes, in the very bones and in the entire systems of nerves and bones. A sensation of hearing, for instance, is first produced by a motion in the air and then in the membranes of the ear; this is then communicated from one membrane to another, from one nerve to another, from one bone to another; and as all the membranes are connected one with the other, and as the membranes and the nerves join and make a common system, it follows that the least tremulation in a nerve or a membrane is able to distribute itself over the whole connected system of the body. The bones, also, are joined one with the other, and each is surrounded with its own membranes, so that as soon as a tremulation enters into a bone, it flows at once over the whole osseous system, as shall be proved in what follows. Our theory is therefore, that every part of what is rising in the body lives by means of little tremulatory motions which flow into the nerves and the membranes and set the whole system into sympathetic tremulation; and that as soon as a contremiscence is distributed over a whole body, it may be termed a sense or a sensation, and that if all the contremiscences of the senses are taken conjointly, they possess the name of nature, or of life. This, then, is what is to be demonstrated. (Nerve transmission-radar, Osmosis-radio)
I. In order to form a correct judgment of the more subtle motions in our organism, and of the more invisible contremiscences, and in order to show where life really resides, let us consider the testimony of the greater undulations in our body. The origins of the lesser ones, and the beginnings of tremulations can be found only in undulations. The lungs, in the first place, are the fountain of a multitude of motions; here the external air is first received; the inflated Organ makes greater or smaller expansions and communicates its motions to everything in its connection, and these motions are undulations, which are nothing but a grosser degree of tremulation. The heart, also, has its own motion: wringing and twisting itself in and out, it propels the blood through the arteries into the veins, and thus, by its pressure, it effects the circulation throughout all those blood vessels and channels of which the body chiefly consists. While it is true that this rising, motion of the heart cannot properly be called an undulation, yet, so far as the circulation is a reflected movement, going and rebounding to and fro, even though by a circular course, it may still be named an undulatory or vibratory motion, like the motion of a horizontal pendulum, though here somewhat by a spiral. horizontal pendulum, though here somewhat by a spiral. The braise similarly possesses a reciprocal or undulatory motion, which accommodates itself to the wringing motions of the heart, or it may be that the latter moves in obedience to the undulation of the brain; moreover, it has been discovered in our own age that the medullas, both the oblongata and the spinalis, vibrate and respire and rise and fall as if in fermentation. If n hypotheses be allowed to mingle with anatomical experience, we may easily suppose that these undulations propel a fluid into the nerves (just as takes place with the blood in its more open and hollow vessels), and thus to the extremities or membranes; these membranes reciprocally returning the fluid through the nerves back to the meninges of the brain, over which expanses the tremulation flows in the first instance. The brain, therefore, is a fountain, whence flows a fluid ; through the nerves to the membranes, keeping the latter expanded and in proper condition. This, then, goes to show that nature is everywhere endeavoring to communicate life by means of a circulation, and especially by means of undulations, that is, by greater or lesser motions of tremulation.
As was said, nature, and consequently all that is living in us, is in the effort to proceed by help of tremulations. As a proof we may first adduce the testimony of what is visible. Consider speech, for instance: words are to be expressed and sound is to be communicated, by distinct articulation, to the hearing and understanding of another person;-this, then, is effected by little atmospheric vibrations which are formed between the folds of the tongue and by means of the air being strained or filtered among these folds, as also through other turnings and twistings, all of which make the tremulations distinct and articulate. If the sound of A is to be expressed, the palate and the whole formation of the mouth know at once how to open the way to let the sound flow forth in a different manner than if a B or another sound is to be produced; these being some of those twenty or more varieties of tremulation which,can be formed in our mouth. This is therefore a proof that tremulation produces everything of speech.
Tremulation, moreover, often shows itself throughout the whole nervous system, to such a degree that it is called tremor, shivering, convulsion; these are really nothing but coarse tremulatory motions in the whole nervous system, showing that the nervous body is disposed to permit the tremulation to play freely over its field, and that there is such a conjunctive comascation between all the parts that a tremullation is distributed over a who e system as soon as a sing e nerve is touched. It has been observed that this kind of tremulations shows itself when the membranes become empty of blood, or when something in the nerve becomes torpid, so that the fluid cannot play in proper freedom, or if a membrane or nerve is injured or loses its usual tension and becomes slack. Hence it is evident that a single tremulation may in a moment spread over entire systems,and thus over that whole part or body which is in a state of tension.
Tremulation is exhibited in a somewhat less degree in the periostea, and is often noticed as a delightful contremiscence beneath the pericranium, as it were; this is occasioned by some pleasantness which plays and titillates in the mind, producing an harmonic motion with such a decree of excitation that it makes itself felt even in the membranes of the external brain(see Pavlov's "irradiation"); the same, also, is often occasioned by a sudden feeling of astonishment which is mixed with a certain degree of fear, when one may consciously feel how the tremulation flows over certain membranes like a wave of cold water, and over the head like the most delicate undulations beneath the roots of the hair, which then often feel as though they were rising and standing on end; whence there is distributed over the whole body a tremor or passion often growing into a greater trembling. This sensible contremiscence must necessarily accompany the motion which is taking place within the dura mater itself, for the pericranium is known to be so joined with the interior meninges by little fibrils and tendons, that whatever takes place in the interior, must become sensible also in the exterior. Such a sensation, therefore, is often the alternate of a passion which proceeds by a tremulation, gradually increasing, distributing itself over the matres in the body, and consequently communicating itself to the nervous system and to the membranes of the periosteum.
The tremulation, in a still less degree, may be felt by a person who falls into a passion, no matter of what kind: (laughing, screaming, jogging, dancing) when the passion has cooled off, there follows a contremiscence in the whole nervous body; but if the mind is to be able to reflect properly upon this subject, it must not continue in the disturbed state which necessarily prevents the tremulation from becoming sensible, but it must fall into a state of tranquil thought, and then in each finger, and in each limb, there will be felt an internal tremulation over the whole body, as will be described more particularly toward the end of this treatise. All this, therefore, is a sensible proof that the tremulation endeavors to ultimate itself in the whole nervous system, or rather, in the whole body and it shows that nature must express itself by means of tremulation, as in the greatest things, so in the leasts.
2. Touching the geometry of tremulation, it is to be observed that there are various degrees of this motion, greater and smaller, just as in local motion there are degrees as to swiftness and slowness. Local motions can be so slow that the sense of sight cannot observe any changes as to distances, except through a long period of time; such motions, for instance, as those of the hands on a watch, which point out the hours, and measure days and months. It is the same with those local motions which the stars and planets are making before our eyes by their orbits in the universe; unless we calculate such motions by the help of time, our senses might imagine that these bodies had no motion whatever. Local motion may, on the other hand, be so subtle and swift that it vanishes from our sensation, as in the case of a bullet which travels through the air and traverses our sight so swiftly that we can make no observation of its course. And yet both the slow and the swift are local motions.
Our tremulatory motions possess similar degrees of swiftness. The most sensible and visible, which is the first degree, is undulation. This, as has been said before, is exhibited in the greater motions of our body, which are the motive springs of the minor motions which may be designated tremulations. All this may be compared to a great wheel governing a thousand minor wheels by which it effects the motion of the whole machinery. (Integrated electrochemical motions)
The same greatest degree of tremulation, which is named undulation when its swinging motion may be distinctly seen, can be observed in many other things: a ship's mast, resting on its keelson and with the other end in the air, will undulate from the least cause, seeking to regain its rest or balance, which was about to be lost by the weight or overbalancing of the top; if an elastic ball is thrown against the floor, it will rebound and make undulatory reflections up and down, these reflections gradually growing smaller and smaller, until finally, by increasing efforts, the ball returns to its own rest and balance; a pendulum, which is left to move freely in the wind, will also make a vibration or a horizontal undulation, and this motion is altogether of the same character as a tremulation, as will be described in what follows, for the better understanding of the nature of tremulation. If an element, such as water, comes into a state of undulation, it drives out waves and rings on all sides round about, and makes circular oscillations further and further from the center, presenting a visible tremulation, similar to the motion in the air which produces sound. The latter, as has been said, flows up and down, making smaller and smaller waves, until an equilibrium has been restored and an even quietude reestablished. From all this it may be seen, that the tremulatory motion, no less than local motion, possesses a greatest degree of slowness, and that it is this degree which is termed undulation.
The second degree of this motion commences at the boundary in which the undulation terminates. As soon as an undulation begins to become audible however coarse or dull be the sound then begins that swifter degree of undulatory motion which is properly termed tremulation, and which embraces all that sphere of vibrations (visible/audible spectrums) that is produced by sounds and chords. For it is the greater or lesser swiftness of the motion that causes the sound in the air to be heard, or makes the tremulation to reverberate in the air, communicating it to the tympanum and the other membranes; a less degree of swiftness produces the grosser and duller sounds, while a greater degree makes the finer sounds, until the swiftness vanishes in such a subtlety that the tremulatory motion again escapes the observation of the organ of hearing, just as the local motion finally escapes the organ of sight, as was said above. Within this degree of tremulation we must, therefore, include all sounds, from the deepest to the highest; by certain experiments it may be observed that at least one hundred and fifty vibrations in a second make the highest c in a piano, while thirty or forty vibrations produce the lowest c; certain tremulations, of the most slow or undulatory character, may even be noticed by the eye, like a mist around the string, but the finest tremulations of the string escape the eye and finally also the ear.
The third degree of tremulation begins, therefore, where the vocal or harmonic vibration ceases or vanishes from sight and hearing, and this degree should be termed contremiscence or sensation. Commencing when the vibration becomes more rapid than two hundred in the second, it may increase in swiftness until it reaches one or two thousand within the same time, when it is no longer to be followed by the sight or hearing; the other senses, therefore, such as taste, smell, and touch, must then assist in order to comprehend the sphere of this degree of tremulation and to apply it to our motive life-force, as shall be further developed in what follows.
3. Our conclusion is, therefore, that our whole living and moving nature endeavors to itself by means of tremulations. The greater of these motions keep all the grosser parts of the body in an even movement, as also in a state of tension and expansion for the reception of the minor motions; the latter, again, are in themselves new motive forces and the sources of the motions of the finer parts of the body, and of the most delicate degree of tremulations. This may be illustrated by a clockwork, in which a hundred different little wheels are set in motions by the motion of one greater wheel, or even by a single vibration of the pendulum. It is the same in our body, in which the lungs, the medullas, or the cerebrum all of which possess an undulatory motion act as the motive force for all the grosser corporeal parts, preparing the way for the harmonic flow of the finer tremulations. This shows, therefore, that the grosser motions of life consist in grosser tremulations, and that, imitating these, the finer motions consist in finer tremulations.
THE NERVOUS SYSTEM
1. IT was said that the motion which effects a sensation in our body, consists of a tremulation in the whole system, as well the nervous system as that of the bones, but it cannot be expected that reason will give its consent to this assertion before we have placed before it all the facts from which the connection of all things may be seen. And as Willis, Vieussens, and others, have enriched anatomy with the knowledge of the exact position of every part in the body, we ought now to preface the treatise itself with a short anatomical account, in order to make possible a clearer comprehension of the nature of tremulation.
It should therefore be known that beneath the cerebrum and the cerebellum there is a medullary part called the medulla oblongata, which is provided with many protuberances, glands, and other processes for the distillation of the fluid which is necessary for the membranes, nerves, and bones; of this fluid more shall be said later on. This medulla is afterwards continued all along the spinal column, down to the legs below; it runs out of the cranium through an opening called the great foramen of the occiput, entering thence the vertebra; from all along this medulla, counting from the cerebrum above, there spring forth, at certain little distances pairs of nerves which hence proceed to their own functions and uses in the body. Leaving the medulla, these nerves run hither and thither, joining and twisting about one another, again separating in order to join with other nerves, then proceeding further away, splitting up and making greater and greater ramifications, until the ramification itself produces an expanse, which is termed a membrane, or a periosteum, consisting of nothing but the most minute and extreme branches of the nerves.
Beginning from above and counting the nerves in their order as they run out of the two medullas, we find first the olfactory nerves, which run directly to the nostrils. Next come the optic nerves, which, running out of their thalami, afterwards cross each other, and then again unite, after which each one runs to its own eye. The third pair runs to three muscles behind the eyes, giving them power to move and turn. The fourth Pair proceeds also to the eyes, running obliquely across the other nerves, and making a muscle with a knot or pulley, called trochlearis. The fifth pair has an extensive ramification; it runs in four branches to the eyes, and thence to the eyebrows, the forehead, the nose, and the temples; other branches proceed to the jaws, the lips, the teeth, the palate, and the throat, afterwards sending out a few branches to join with the sixth pair, which also runs to certain motor muscles of the eye. The seventh pair is called the auditory nerves, which are double, the one soft, the other hard: the former runs to the tympanum, the cochlea, the muscle of the malleus, etc., the latter inclining towards the eighth pair, to the tongue, the pharynx, to certain muscles above the mouth, and around the eyebrows and the forehead, etc. The eighth pair, which is called par vagum , describes an extensive circuit, running to the muscles of the neck, to the hard branch of the auditory nerve, and to the intercostal nerve; it then runs down the body in a straight line, on the way sending out branches first to the cardiac plexus, whence the heart receives its nerves and ramifications; then to the heart itself and to a number of arteries and veins around which it weaves itself; also to the esophagus, to the lungs, to the stomach, as well beneath as above, terminating finally with minute branches in the liver. The ninth pair runs mostly to the tongue and the palate, and unites afterwards with the next pair. The tenth pair runs simply to the muscles of the neck, but unites on the way Keith various other nerves, as with the great intercostal nerve, and with the spinal nerve. The eleventh pair goes mostly to the muscles in the neck and to the diaphragm, uniting finally with the following pair. The twelfth pair proceeds to the arms and to the diaphragm. The thirteenth and fourteenth also to the arms; the fifteenth to the twentieth, etc., run to the muscles in the arms, the sides, and other parts of the body, uniting mostly with the intercostal nerve; the thirty-first and thirty-second to the testicles; the thirty-third sends a little branch to the penis. The thirty-fourth to the thirty seventh run only to the muscles in the legs and the loins; the thirty-fourth to the inguinal glands; the thirty-eighth unites with a nerve which runs to the thighs, but runs otherwise to the sphincter muscle of the anus, to the prostate glands, the bladder, the uterus, and the rectum; the thirty-ninth , like the others, runs into the intercostal nerve, as also to the cranial nerves, to the muscles of the penis and the anus, uniting thus with the former ones, and these again with those that run out of the intestines and the me enters and these finally with all that system which is produced by the intercostal nerve. Most of the above nerves unite to produce a great nerve, called the intercostal nerve, which runs to and from nearly all the parts of the body and effects the principal connection of all the other nerves. The intercostal nerve may therefore be called a connecting sinew and a basis and highway for all the nerves in the body, as may be seen more fully from the whole nervous system, as described and illustrated by the anatomists.
For the further elucidation of tremulation let us consider the most minute parts of the body, and we will see that there is a connection and harmony between all these parts, no matter where they be situated. Take, for instance, any little nerve or point of membrane in the stomach: it will be noticed, first, that both the upper and the lower parts of such a nerve or point are joined to transverse sinews and afterwards are incorporated in the par vagum nerve, which runs to the esophagus, the lungs, the heart, the pericardium, the throat, on the way weaving itself about arteries and veins; it finally flows into the intercostal nerve and now describes another great arch in the body, running to the kidneys, the spleen, the liver, the gallbladder, and round about the intestines and the mesenteries; it is thus connected with the branches of all the other nerves which join the intercostal, anti is therefore connected also with the legs and the loins, the head, the face, and all the organs of sense, etc.; finally, by a circuit, it becomes again connected with the par vagum, which terminates in the stomach. Or take any other part of the body, such as the least cuticle on a finger, or on the sole of the foot, and it will be observed similarly that this cuticle, which is nothing but a ramification of nerves, is collected into a greater nerve, and afterwards, by means of other nerves, becomes connected with all other cuticles and membranes in the whole body.
This is, therefore, another clear proof that every sensation is a tremulation in the whole nervous system, (neural transmission) and that a sensation is not confined to any particular place beneath the cerebellum or within any certain protuberance or ventricle here or there, but that it exists as in one, so in all places simultaneously; before it can properly be called a sensation it must have been felt in every part of the body which is reached by a nerve. As soon as the least impression is made on the ramification of any nerve, it is at once communicated to all the nerves and membranes of the whole body, so that one and all must necessarily be touched and impressed. The most direct highway of sensation is the medulla spinalis, which, as to its tunics, is contiguous with the brain; the sensation or tremulation is therefore at once communicated to the medullary tunics and to the cerebellum. As now all the sinews, threads, or nerves, which are found in any part of the body, originally come from this medulla, it may be understood how the tremulation as soon as it reaches the fountain or origin of all the nerves must run like s a lightning over them all, in whatever corner of the body they may be. That is, the tremulatory motion is received especially by the medulla spinalis, whence it is Communicated to everything contiguous with this medulla, namely, the brain, and all the nerves, membranes, and cuticles in the whole body, all this showing that a living sensation is not confined to any particular body of matter or little protuberance in the brain, but free from any bridle or constraint, it runs like a lightning over the whole body, and then first presents the sensation. (irradiation->sensation)
2. Having now exhibited the connection of all the nerves, and the harmony of our whole body in respect to its sinews, it will next be necessary to deal with the system of the membranes, inasmuch as the tremulation flows over these up to the cerebrum, using the membranes as a bridge over which it is carried to its termini above and below.
In general it is to be known that a membrane is nothing but a contexture of nerves, which by countless ramifications have been woven into a tissue or coat, to clothe and distinguish the various parts of the body. By the microscope one may distinguish innumerable filaments of nerves, entangled and crossing one another; the lymph flows in some of these filaments, the arterial or venous blood flows in the others. According to the latest discoveries, the membranes consist mostly of nervous lymphatic ducts, the blood vessels constituting the lesser part: all these, infinitely ramified, produce an expanse like a retina. Every least part of the body is thus clothed with a membrane, thick or thin according to the use and nature of the part, and often with two or three membranes in which the nerves terminate and thereby compose the chief structure of these membranes. Such is the composition of the stomach, the mesentery and everything else, as is held for certain by some perspicacious scientists.
Chief among all the membranes are those which are called matres or meninges: the upper one, which differs from the other as to thickness, is called dura or crassa mater; the lower one which is thin and fine, is called gangs or pia mater. It is in these that the principal motions of tremulation take place; in these reside most sensibly the most subtle sensations, and in these, as in little mirrors, may be seen the real nature of tremulation.
The dura my be said to produce an expanse over the whole body, for it communicates membranes and tunics to all parts, making a continuous system just as the nerves do. It is expanded over the whole brain, extends itself into all fissures, as between the cerebrum and the cerebellum, and surrounds the medulla spinalis throughout; all the nerves which flow forth from the medulla similarly cover themselves with a tunic from the dura mater and carry it with themselves to all parts of the body. As now the nerves to send out ramifications to all the periostea, to all the muscles, and to all the blood vessels, it follows that the dura mater provides clothing for all these parts, forming all cuticles, periostea, and integuments in the body, so that the whole contiguous stem of membranes is nothing but a continuous extension of the dura mater. Beneath this latter lies the pia mater which still more encloses all parts which are distinct from one another. It surrounds especially the cerebellum and enters into every sinus there; it covers all the protuberances and glands of the brain with little membranes, gives a tunic to the ventricles, runs along all the nerves which flow forth from their roots to their foramina in the cranium, accompanies the medulla along the spine as an inner coat and divides it into two parts. In a word, it encloses inwardly everything that is of a lymphatic or soft nature.
Between the dura and the pia mater the anatomists have also found a thin membrane, called the arachnoid. This one encloses the whole medulla spinalis, and, I believe, also the cerebellum; it lies so close to the pia mater that many may suppose it to be the uppermost tunic of this mater, but it may be seen most distinctly at the punctures whence the nerves come forth from the medulla spinalis. This arachnoid. membrane also accompanies the nerves as a second coating, continuing perhaps, to the smaller ramifications as covering lamina and producing a great number of tunics and periostea. The meninges of the brain, therefore, produce a continuous system of membranes over the whole body, and as this whole system covers a structure of continuous vessels lymphatic as well as sanguineous and all filled with their own fluids, it follows that these membranes are hereby kept expanded and distended for the requirements of the tremulation, being more or less attuned, as it were, according to the influx of these fluids. But of this more will be said in another chapter, in which we shall demonstrate the theory of the circulation of the lymph and the blood.
3. It must also be shown how the bones are connected and articulated one with the other, inasmuch as on this connection depends to a very great extent the instantaneous communication of the tremulatory notion. A skeleton clearly demonstrates this connection. It should also be remembered that every bone as to its least part is enveloped by a periosteum, that is, by a membrane extended from the dura mater (although the temporal bone has been excepted by some, yet not by ball the anatomists). The dura mater, therefore, applies itself closely to the bones, seeking as it were to incorporate itself with them in order to give them nutriment by its fluid. It also extends little tendons or threads far into the substance of the bones, thus joining the membrane so closely that it can hardly be separated from the bone. In the cranium itself the dura mater applies itself so firmly to the rough surface of the bones, that it is difficult to separate it without causing some injury. By little tubules and points it is also joined to the pericranium so firmly, that nothing is felt in the one which is not also felt in the other membrane. Moreover, in the great foramen, through which the medulla spinalis enters from the head into the vertebrae the dura mater is so swollen that it seems fibrous and fleshy; the reason for this is that all the tremulations must flow through this opening, as through a bridge on a violin, before entering the concave part of the cerebrum.
4. From the above we may now have a better comprehension of the communication of tremulation. For it is known that the tremulation flows with the rapidity of lightning over membranes and nerves, from one end to the other, in an instant making the most subtle waves over the whole expanse, like the oscillation in water or in the atmospheres. As now all the membranes are expanses, and are continuous with the aura mater, and as the meninges surround the medulla spinalis, divide it into two, and enclose the whole cerebrum and cerebellum, it may be seen, in regard to the nature of tremulation, how quickly this will vibrate from one terminus to the other. It is so swift, in fact, that we cannot form a conception of its celerity by any comparison with our divisions of time. It has been shown further, that all membranes are joined with what is hard, that is, with bones, from which it follows that every tremulation in the membranes is at once communicated to the bones; the same motion that begins in the nervous system is instantly communicated to the osseous system, thereby assisting the tremulation as well in respect to the swiftness of its distribution as in respect to its continuation in the same degree throughout. For if there were no contact with something hard, the expansion of the membranes would not be sufficient to effect the communication of the tremulation so swiftly, inasmuch as this motion always loses somewhat of its force when it meets anger thing that is soft. When we examine the periostea, which surround vertebral foramina, it will be seen that these are, indeed, separate tunics, yet derived finally from the dura mater, so that there can be no tremulation in the one which is not ultimated in the other. The tremulation is therefore at once communicated from the spine, with all its membranes and vertebrae, to the cranium; the latter, which is the exit and entrance or the very bridge of all tremulations, is so completely joined and fixed to the matres, that any motion in one part must necessarily be felt at once in all the parts of the head. Moreover, there are concave cartilage's on all sides, anal the cranium itself is so porous, that it is especially fitted for the reception of what is tremulatory. For porosity contributes more than anything else to the communication of the finer contremiscences; the more porous a thing is, the better does it play with the tremulation of a chord; porous wood, such as cedar or Spruce, is far more Suitable to conduct the sound of a chord than any harder' of wood. The all wise God of nature has therefore created in man a great cavity, surrounded by a very porous cranium, so that it is like the body of an instrument, from which the membranes receive a higher tone or pitch, for the effecting of sensation in the body. And as each one must form his own opinion according to his own brain, we may be allowed to express our belief that the tremulation first runs as far up as to the great foramen of the occiput or the interstice of the medullas, and thence into the cranium to the coronal suture. For the matres are here joined to the cranium, and in the foramen they seek as it were to attune the Sound, like a bridge on a musical instrument, whence it flows up and down, and effects in us the quality of the tremulation. Quod erat demonstrandum.
I. It was said that the membranes, over which tremulation flows and which carry the motion into the cranium and over the whole osseous system, are of the same quality as a musical chord. To originate a sound there must be a tightly stretched string no less than a well built body of porous wood; the fittest sounding boards can effect no sound if the strings are slack. Thus also with the membranes in our body: such as is their tension or expansion, such will be the communication of the tremulation the osseous system, and such will be the increase of the sensation; but as soon as they become slack, they can communicate no tremulation for the production of sensation, even though the bony system is perfect and in all the strength of maturity.
It is now our intention to show how the membranes become expanded and attuned to receive the tremulatory motion by means of the influx of blood and lymph into their respective vessels. When these fluids press in with force and swiftness, they cause all the ducts and minutest vessels to swell up, and as the membranes consist of nothing but such vessels, it follows that the whole membranous system then becomes expanded and distended. On the other hand, when there is present any force which expels the blood or the lymph from their vessels, it follows that the membranes are let loose and become like a slack string which only can vibrate very slowly and scarcely is able to conduct the tremulation to the bridge of the instrument. The degree of fullness of life is, therefore, according to the decree of the tension of the meninges: the more these are expanded, the swifter is the course of tremulation, and the greater is the degree of what is called esprit and presence of mind; but in the degree that the membranes as it were collapse and perhaps conceal some serum or lymph beneath their folds, in the same degree is the tremulatory motion prevented, and in the same degree do we suffer from absence of mind and of understanding, the body no longer responding to what is quick and prompt.
As now the tension of the meninges is the most necessary condition for any proper kind of tremulation, let us next consider the circulation of the two principal fluids in our bodily system. It is hardly necessary to say anything here as to the circulation of the blood as much as Anatomy is very rich in knowledge on this subject. The general opinion is, however, that the blood flows from its center, or the heart, through the arteries, which gradually ramify into finer and finer arteries, until they finally terminate in little branches and delicate vessels, to the number of many thousands; all these are distributed not only over all the cuticles, but over all the membranes which are visible in the meninges and in the choroid plexus, until they present a reticulated expanse, figuring in the membranes like the finest ramifications anal leaves of a tree. After the blood then has followed the arteries into these least ramifications, it flows into the venules, and thence, by the same pressure, into the larger branches, and so, finally, through the greater veins back again to the heart to repeat the same circulation as before.
While such is the circulation of the blood through the arteries and veins, there are other little ducts, called the lymphatic vessels, which run as it were out of the wall of an artery and across to a vein, like little aqueducts pouring their fluid into the blood which is to return to the heart: these aqueducts are lymphatic nervous vessels, each surrounded by most minute nerves and membranes. Now, though the microscope has discovered something of this order, still we do not suppose that any one is as yet able to claim a knowledge of the fountains of these rivers. (SWEDENBORG'S GREAT NEURO-TRANSMITTERS HYPOTHESIS) But if we are willing to follow the guidance of sound reason, acting on the suggestion of what has been observed thus far, we cannot but conclude that just as the heart is the propelling organ of the blood, so are the cerebrum and the medulla the fountain of circulation of other fluids in the body. It is known that the cerebrum and the medulla have a reciprocal and undulatory motion, just as the heart; this motion must necessarily cause a fluid to be pressed in and out continually, propelling it to the extremities, and thence back to its original fountain. Now, out of the two medullas there flows in the nerves a fluid called the nervous serum,--as will not be denied by any person of common sense, for it is known that the nerves are humid; the same may be observed in the wood of the hardest tree, in which the sap flows up and down through the pores to all the parts of the tree. These nerves are again ramified into finer and finer branches, until they are finally expanded into membranes which clothe all parts of the body; these membranes, in their turner provide a new sheathing for the nerves, and thus accompany them back to the medullas. The fluid, which has poured itself through the fibrils of the nerves to the extreme tunics, has thus an area or space in which it may either unburden itself or else flow back again to the matres and meninges as to its own source, just as the blood returns to the heart.
It has been shown by Vieussens that these membranes extend thousands of threads or Iymphatico-nervous tubules on one hand into the bones and on the other hand into the arachnoid. and the pia mater. Through these the lymphatico-nervous vessels cause to be distilled into the medullas a fluid which that author would almost acknowledge as an animal spirit; this fluid has thus flowed out of the medulla through the nerves into e the membranes, and then back again to the medulla, making a circulation similar to that of the blood. this, at least, seems credible to us, and it is also possible that the lymphatic vessels run only from the walls of the arteries into the walls of the veins, that is, from nervous tunics into other nervous tunics.
As now the blood has its own sources of distillation, that is, the lungs, the glands, and the chyles, which form the blood before it comes into circulation in the arteries and veins, so also does the nervous fluid possess its own glandtlles, ventricles, anal vessels whence it is distilled in the brain. But let us consider these in their order. It is known that the dura and pia mater are covered on tile surface by little sanguineous and lymphatico-nervous vessels; these, again, send little tubes into the cerebrum, pouring into it the fluid which the cerebrum afterwards is to distill and pour into the medulla. The pia mater is therefore, at first, almost united with the cerebrum; the upper part of the latter, which is ash colored, is called the cortical or cineritious part, and consists of little glandules which distill the fluid; below this is the medullary part which is whitish and consists of little stri and tubules, through which a fluid may be seen flowing out of the cortical part. The cerebrum is, moreover, divided into two hemispheres, between which lies a hard medulla, called the corpus callosum; all along the latter, towards the ventricles, there is a soft substance which has been called the septum lucidum. In each hemisphere there is a ventricle or cavity surrounded within by the pia mater; between the two ventricles there is another called the fornix, and Still another, smaller one, has been found between the cerebrum and the medulla oblongata. This medulla arises from four roots and possesses two cornua from the cortical part of the cerebrum, as also from the cerebellum; these cornua are called pedunculi or processes. On the top of the medulla oblongata there is the annular protuberances surrounded with its pia tunica, and in connection with it there are two other globules, one on each side, from which arise the optic nerves, whence they are called the thalami of the optic nerves. The cortical part is inmostly in these thalami, but the medullary part is on the surface. Just below lies the infundibulum, also surrounded with the pia mater, and ending in the pituitary gland. Next follows a number of other little glands and protuberances, such as the corpora striata, the lineal glared, the ages, the sates, testes. corpora pyramidalia and olivaria, the pons Varolii, etc., concerning the nature and position of which one may consult the anatomists. Below all these the medulla runs through the great foramen of the occiput, and enters the vertebrae, where it becomes known as the medulla spinalis.
Returning now to the nervous fluid, we will understand that it is ever flowing anew from the meninges through the little lymphatico-nervous vessels, which by means of tubules carry their burden into the most minute glands of the cerebrum; from here it flows into the rnedulla and through the nerves into all the membranes and all the finest and most remote expanses of the body. It thus also flows into the muscles, where the nerves at each point send forth most minute filaments like a fine net or web; these are supposed to close in the veins and to reciprocate themselves through the heart to the finest ramifications of the arteries, anel so, in the same manner, to the brain. It is also to be observed that the inmost kernel of the medulla spinalis is a cortical or glandular substance, the other or external part being medullary, consisting of continual strife which receive the fluid from the membranes and carry it back to the brain, to be distilled over again for new use in the nerves.
It would seem that there is a difference between the lymph which drips forth from the dura mater and that which comes from the pia mater, and that both of these kinds are different from the nervous serum itself. This difference, which is not yet clearly understood may perhaps be illustrated by the difference in the humors of the eye: the humor which flows between the lamely of the tunic of the eye is supposed to be the same with the fluid which is distilled by the dura mater; this humor is aqueous and not especially sensitive, but mixed with urinous matter or with a subtle salt which as yet is but little known to chemistry; the crystalline humor, which also is the hardest, and which has its own globe or adytum in the eye, seems to be distilled by the pia mater, for the tunics on both sides of this globe are an extension from the pia mater; nevertheless, as numerous little arteries run into it, and as it has a still finer tunic on the outside, we are unable to make any certain Conclusion on this point; the third humor, which is called the vitreous, and which lies almost on the retilla, seems to flow immediately from the optic nerve and its thalamus, and it appears that the nervous serum has considerable affinity with this humor, not only because it possesses an even viscosity, being neither too fluid nor too tenacious or viscid, but because in the most minute networks it makes an expanse by its mucus which flows in through the optic nerve. All this, however, has only been said by way of suggestion.
However this nay be, it shows at least that there must be a tension in the membranes if any proper kind of tremulation is to be communicated over the whole of their expanse, so as to effect a sensation in one thing or another. This tension can arise only from the infilling of the vessels, whether it be the blood-vessels or those through which any lymph or juice is circulating. In the blood-vessels there is a certain degree of heat, while the other vessels possess a Certain degree of coolness, anel both regulate anal moderate the natural heat of the living body and produce the proper expansion of all things. Any obstruction in either of the fluids causes an obstruction either in the nerves or in the other vessels in the membranes, and prevents that tension which alone enables the tremulation to present a living sensation.
2. As now the finer degrees of tremulation require an expansion or tension in the membranes, and as the swiftness of the motions and the consequent intensity of the sensation are according to the degree of this tension, it follows that slack or flaccid membranes cannot possibly serve for any subtle activity. In a new-born infant, for instance, everything is still soft and unripe, and there is,therefore, little or no activity; with an adult , on the other hand, everything has reached its proper expansion, and all tremulations consequently flow promptly and forcibly to their effects. as well in respect to comprehension as in respect to expression; with the very aged, finally, an things must move slowly, and approach more and more to a state of dullness. because with them all the membranes have become slack and wrinkled and receptive only of the coarser undulations, so that they can have hardly any contremiscences in their whole being.
If now, from any accidental cause, the tension has been removed from the membranes, either by the blood being expelled from the finest arteries or by the nervous fluid being stopped up in the little foramina, the effect will at once be externally observable: the senses can no longer perform their functions, and the thought and the memory no longer remain distinct, but the man becomes like a mere form, almost void of life, the vital fire being gradually quenched and approaching a state of quiescence or death. This may be illustrated by the conditions of the body during various states of passion and affection.
A sudden fear causes the blood to rush back to the heart in an instant: it fills up the greater veins, withdraws from the finer arteries, and completely exhausts the most minute vessels; the muscles are deprived of blood; pallor covers all the extremities, the membranes also become exsanguious, they lose their tension, lie down slack, and become altogether unfit for the reception of a tremulation. Hence each one of the senses is deprived of the greater part of its sensitive power; the eye loses its acumen, and the same happens to the ear and the other organs; the thought and the imagination become indistinct, and the life is in danger, nay, is sometimes extinguished before the blood has been able to force its way back to lift up the collapsed vessels. Sometimes there follows a tremor, a quivering, a stroke or convulsion throughout the body, for the greater part of the life is lost as soon as the tremulation no longer can flow over a stiff expanse.
Amazement produces similar effects, in so far that everything in the body then displays a tendency to come to a standstill; even the involuntary motion seems to have stopped; the blood has hardly any impulse toward a new circulation; a general state of forgetfulness anti stupidity results, with a limpness and placidity in all the membranes, until finally a more full tremulation is able to pass over them.
Swooning is also of a similar nature: through a sudden alteration the nervous fluid or the blood rushes out of the membranes or else becomes obstructed in one place or another so as to be prevented from flowing forth to its expanses, networks, and membranous plexuses; the latter, therefore, collapse at once and become unable to receive any further tremulations, and the subject remains as it were half dead, until the blood can again flow into the membranes and expand them as before, when the life finally regains its termination and the tremulation its life.
In paralysis or other convulsions it is known that something has closed the road to the membranes or nerves through which the fluid must pass, and consequently has obstructed the motion which ought to glide over these as the proper bridges for communication in the body. Such strokes and obstructions show conclusively that there is a real circulation of the lymph, for if the fluid is obstructed in the nerves, then their membranes no longer receive any of that Iymph which must flow out to the extremities of the nerves, but they lose their tension, and the tremulation comes to a stop at the very beginning of its course without producing any sensation in the entire half of the body.
In the case of those who have died of apoplexy, or have lost the real acumen of their senses through a wild or extraordinary tremulation in the bones and the cranium, it has been observed, when the skulls of such persons have been opened, that the dura mater has been bloodless and slack, sometimes twisted into folds and wrinkles, and sometimes with the Iymph exhausted between the dura and the pia mater; the cortical and medullary parts have then been found soft and watery, the glands and the pituitary body distended, the ventricles filled with viscosity, the medulla spinalis quite rheumy and as it were inundated by stagnant water; many such cases will be found described by those who have investigated and made notes of such things. All this gazes to show that tremulation is a fac-totum as to everything living in our body, for as soon as the little membranes are no longer in a state of tensional but folded and slack, we lose all that is initiative, that is, we lose our senses, our thought, and everything else that makes us truly living. On the other hands it is wonderful to observe how everything gains a new life, each sense a new presence, and each different sensation a new alertness, as soon as a new circulation takes place, by which the fluids may again flow forth to their extremities to expand each minute vessel and hence the whole expanse or membrane which is woven together of such vessels.
In a state/psycho-somatic condition of courage, for instance, the blood flows forth into all its arterial vessels until it reaches the veins; it is then impelled into the very cuticles, and spreads a blood-red or crimson color over all the tunics; the two matres, also have now become full of fluid and thus expanded, so that the tremulation is able freely to play over them in swift motions; all the senses possess their proper life, and everything has its proper termination, comprehension, and presence.
If by any other passion, such as that of Amor and Venus , the blood has been driven into the extremes of the rnembralles, it will again be observed that all the little membranes have become expanded for tremulation to put vigorous life into all the sensations. A Condition of anger causes too hasty a circulation of the blood, fills up the little vessels too abundantly, and distends the canaliculi too greatly. The same is the case in a state of heat/over-heating, as in a sickness or fever: the smallest vessels swell up into bladders, as it were, driving the internal fire into the very cuticles.
Thus also in drunkenness, when a person has too freely imbibed such fluids as make the blood volatile: the blood then presses forward so as to expand and swell the sanguineous vessels too strongly; each sense then reaches the highest degree of its life; the tremulation becomes uncontrollable, making wild and disorderly movements in place of the ordinary and even ones. If the quality of the membranes be then examined, it will be noticed that they are gradually losing their evenness or smoothness, the sanguineous ducts make tumors here and there, and cover the membranes with waves, as it were, whence the tremulation receives a different quality, and the arteries undulate from the excited blood within. A tremulation may then, indeed, pass over the cuticle and its nervous system, but, since the arteries are thus distended, a softness will be in the road here and there, preventing the proper play of the tremulation, and obstructing the lymphatic ducts through which the tremulation should be Communicated in the first instance; the motion is thus turned into a different kind of tremor, which does not correspond with the usual one; it communicates a dull and stupid tremulation in place of the proper one, and causes what is known as madness.
3.* What great changes do not instantly result from any accidental in jury to the dura mater! Convulsions, swooning, and general collapse follow quickly, and apoplexy often leads to death; in a word, it is the shortest road to the stoppage of our whole moving life. If the medulla spinalis or the cerebellum is pierced by the smallest point of a needle, we know that death follows immediately, sometimes by a lymph being emptied out of its vessels between the membranes or the skin, whence the matres at once become wrinkled and laid into softer folds, to the hindrance of the tremulation which should pass over them. All this shows that our proper life resides especially in the membranes, and accommodates itself to their state of tension or slackness; the tremulation, therefore, accommodates itself similarly, carrying the life into whatever degree that is permitted by the tension of the membranes.
While studying the nature of the membranes and their expansion, it seems difficult to form any other theory than the one here indicated. Now if our life and nature were to consist of something else but those subtle motions which are called tremulations, what then is to be thought of those cases in which men have lost a part of the cortical substance of the brain, and yet have remained in possession of their senses? Cases have been known in which parts of the cranium have been removed by trepanning, when it has been found that the cortical substance has been evacuated by handfuls; other cases are recorded, in which both the medullary and the cortical parts have turned into a purely watery liquid, in which all the formerly distinct parts have been swallowed up, so that no proper glands, protuberances, or ventricles remain, but the whole has become like a slough of water; and yet, not with-standing all this, the senses have remained in their natural condition. We are therefore forced to conclude that life resides in the ultimates and thus in the meninges, and that it will remain there, let the internal parts be as they may, provided they are still able to furnish some kind of an even and proper fluid for the nerves, whereby the membranes may be kept in some state of tension.
Our theory may be seen illustrated still further in those cases where the whole brain has been ossified or petrified. There are on record at least two such cases, one of which may be seen in Professor Dr. Bromell's *beautiful collection. In such cases, it would seem, the fluid must be distilled immediately from the matres, dripping by little pores or canaliculi through the inner, petrified part, as in the case of other bones. It cannot, therefore, be denied but that the surrounding membranes really effect that which is usually ascribed to the inner part, that is, a motion, which is communicated to the whole system of nerves and bones, and consequently to the whole body, for the effectuation of all our sensations.
If a subject of the vegetable kingdom may be compared with an animated thing, it will be seen that nature has a similar character in both kingdoms, that is, that the living and growing force depends upon the coats and the bark through which it is flowing. Take, for instance, a tree, the trunk of which lies broken on the ground: as long as the bark still joins the two parts of the trunk, the leaves and the fruit will still continue to live on the tree; but if merely a strip of the bark be peeled off round about the trunk, all the verdure and growth will vanish and the whole tree will die. From this comparison, therefore, it is evident that it is the pleasure of nature to place what is chief and most noble in what is nest ultimate, and that all life must depend on this ultimate.
Now it may, indeed, be objected, that the dura mater is often injured in cases of trepanning or through other causes, when yet the senses are improved and retrain their proper order; still, when this happens, it will be found that the injury has been received in places which are not especially connected with the general tremulation, for if the membrane over some particular nerve be injured, the collapse does not extend itself further than to the extremity of that nerve. Similarly, if an incision be made in the meninx opposite a suture, the proper tremulation is not thereby altogether lost, although it is made somewhat slower; but if injury be done to such a part of the dura mater as may be supposed to be the very bridge or focus of the tremulations, either on the cerebellum or on the medulla spinalis, then there will at once result a shivering or twitching over the whole expanse, or the vessels will be emptied of the lymph, so that the tremulation can no longer pass over its usual bridge except as over a slack string.
4. As has been said, the tremulation requires a tension for its swift and proper communication to the cranium and the other bones, in order to be felt in the organs of sense. This may be illustrated by the quality of a musical chord, which, if slack, will merely undulate slowly without producing any sound, but, if drawn tight, will gradually give a sound which becomes clearer and sharper in the degree that the chord is drawn toward the bridge. It is the same with a drum: if the membranes are slack, the tremulations hardly reach the hundredth part of their proper distance, but if drawn tight, the swiftness of the tremulation and consequently the strength of the sound are increased so as to reach great distances.
Looking further into the cause of this, we will find it illustrated by the pendulum: the longer the pendulum the longer time does it require for each vibration, but the shorter it is, the swifter the vibration within the same measure of time. Instead of a pendulum take a rope, or line, which naturally hangs in a curve;
if now the line a o b is swung to and fro, the times required by the vibrations of the point o will be equal to the times required by a pendulum of the length of o k. If the line is drawn tighter, the cross-line k o will at once become shorter, like a shorter pendulum, resulting in a swifter vibration at o, and the tighter the line is drawn, or the more nearly into a straight line, the swifter are the vibrations. The idea of the geometricians is, therefore, that the times are as the radii and the length as the squares, which is called a duplicate ratio.* If, then, a musical chord or string always hangs more or less in a curve, it is but natural that the more it is drawn tight, the more does it approach a straight line, that is, the shorter the pendulum k o, the swifter the vibration.
It is the same with a membrane: the more it is expanded or stretched, the more are all the parts of it expanded or drawn tight into straight lines or a straight surface, and the more swiftly can the tremulation pass over this surface; thus also with a string, to which a ball is suspended and swinging, if we take hold further down the string, the vibration will at once hurry on faster; a musical chord, when gradually drawn tight, will at first give a coarse sound, then a finer and finer as it is drawn tighter and tighter. A tremulation in the body possesses exactly the same property, requiring more or less of tension if it is to express properly any sound or sensation.
5. There exist with men many different kinds of genius or temperament, which arise simply from a difference in the nature of the expansion of their membranes. Those are said to be of a sanguine temperament, with whom the blood is thin and volatile, so that it flows like an ether into the least vessels and inflates them in an instant; these persons above all others possess membranes that are filled with blood and are stiff f or the reception of tremulatory motions; all things with them are movable in the first instant and ready for effectuation in the same moment; they are more inventive, more communicative than any other persons, and more inclined to anything that requires blood in the membranes.
Those are said to be of a melancholy temperament, with whom there is a thicker kind of blood which flows with greater difficulty into the most minute of the vessels and hence does not effect its circulation in as volatile a manner; their membranes are expanded only by the greater vessels, and the matres are somewhat slack and less even or smooth than with the former, so that everything with them is effected more slowly. Phlegmatic persons, also, have a slow life, because a lymph or serum seems to predominate in the membranes, the blood having less space or lodging, whence there is less heat in the body. [Certain words in the sentence next following are obliterated in the manuscript, making four lines unintelligible.]
. . . Now, as a mass of ramifications of the nerves weave themselves about the arteries and the veins, not on]y in the body itself, but also in the brain, composing what is called the nervous tunic, it follows that as soon as any passion has originated, the blood is more or less under the control of the nerves; by the contraction of the nerves the blood is closed off from its finer vessels, while by the expansion of the nerves the blood is permitted to flow freely or is propelled forward with increased pressure, so as to expand the membranes. From this cause comes that immutable law which is exhibited in the membranes. For if the blood is obstructed in the membranes, there results at once a different attuning of the whole nature of man.
That life is tremulation, or that whatever is living in us must be expressed by the motions of tremulation, is manifest not only from the connection of every least part, but especially from this fact, that life has a tendency to accommodate itself altogether to the solidity in the systems of the body. For it was shown above that tremulation requires not only a tension, but also what is hard or solid, in order to effect an intensification of the sensation as well as a communication, just as a musical chord requires a hard and concave body, which effects the reverberation of the sound as well as the aptitude of the chord for tremulation; otherwise the vibration of the chord would hardly reach the tympanum of the ear, but would vanish in the folds of the external organ. It is hardness or solidity, therefore, that contributes a higher degree of the perception of tremulation, or which makes us conscious of the sensation, as may be seen from the whole life of man, in all its ages.
Consider the state of a new-born infant: there is nothing fixed or stable in his whole body, no firmness in any bone; the cranium legends to the touch of the finger; there is no consistency in Shoulder or leg; the dura mater has not yet become fixed to its sutures; that which is to become hard is still a serum or a yielding substance, so that no tremulation is as yet able to pass from what is soft to what is hard, or vice versa, to effect a sensation; the meninges of the head lie on a very soft cerebrum; the arteries or other vessels have not yet fixed themselves firmly to their canaliculi so as to prepare the membranes for the reception of tremulation; the cerebrum itself is not able to contribute any expansion or tension to its tunics, but must, like a mere fluid, leave with the matres whatever impression is made upon them. Here we may see, as in a picture, how life, and the use of the senses, must accommodate itself to what is hard, and how all the tremulations are kept back on account of the absence of this hardness. The external senses are not yet fully alive with the new-born infant; he can perceive nothing distinctly; hearing, sight, and all the rest, are to him like a shadow or a cloud, in which nothing distinctive is possible. The cranium being soft, the membranes have not as yet gained any proper expansion, have not been attuned, as it were, but are like loose strings, over which a tremulation may indeed pass, but only with an undulatory and dull motion, without producing distinct sounds, and without power to reach the bridge of the instrument by any other natural motion than the involuntary one.
But the compositions in the body soon begin to gain stability, fixedness, and expansion; the sutures of the skull are gradually closed and knit together, thus drawing the membranes toward the cranium; the nerves also grow harder because the medullary or striated part in the greater nerves is drawn into hard filaments on which the membranes of the nerves lie as on hard bottoms. Life then begins to become properly living, the senses receive their alertness and acumen, everything gains more and more knowledge of its own use and quality. In a word, nature then begins to express itself, the sensories find their termini, and the tremulation gains freedom to pass from ultimate things to inmosts.
Passing by the years of growth, when the various bodily systems are continually adding something to their size and hardness, we arrive at Adult Age, when the efflux of the nervous fluid becomes proportioned to the expanse of the body, so as to give it sufficient nutriment, or when the medulla is fully able to support the full-grown bones and body. our whole system of bones has then become fixed and has gained its proper dimensions and hardness; everything is firm and living; all the senses are in the fulness of their uses, and the internal senses, such as the memory and the thought, are at their highest point of development. The membranes, also, are then most firmly expanded by their vessels, such as the arteries, veins, and lymphatic ducts; the medulla has been shaped into long striae; the nerves have become firm; the bones and the cranium have fully developed their porosity; and the lamina of the bones have gained their hardness, so that tremulations may be properly received. Since now it may be seen that the tremulatory motions effect a better sound or sensation by means of tension or hardness than by the contrary, we have also proved that life, or what is properly living in us which is a distinct perception or discrimination of all things consists in tremulations. For when the compaginations or systems, over which the tremulation is to pass, are out of their order and use through any improper softness, then also is all perception suffering, but as soon as the frame-work is ready, and the whole key-board furnished with taut strings, then only is it able to convey the sound or the perception, which propels itself by means of tremulations.
Now when Old Age comes on and inclines toward the end of life, the condition of the membranes and of the who]e frame is equally notable. The medullary substance, both in the spine and in the cerebrum, is then becoming more and more hard and sinewy, for its whole tendency is to run into sinews. It has also been found that the medulla is more empty of its fluid with the aged than with the young, whence, with the former, the nerves no longer receive their proper nutriment; the fluid flows more sparingly to the membranes and the extremities; the serum and the Iymph become more and more dried up, making the matres more and more slack, wrinkled, and foiled; the finest bloodvessels can no longer penetrate to the surface, but are closed off by the hardening external forms, are kept away from their most subtle ducts, and thus cause the meninges and all the other cuticles to fall into folds and wrinkles; everything is becoming more and more empty and light, and man is failing as to every part. It may thus be seen how the tremulation is as it were shut off from effectingb the life of the senses; the membranes, over Which the motion is to pass, have become displaced, loosened, and slackened; the tremulation must needs stop at the first initiative, or it runs forward in a dull manner, almost without any sound; the acuteness of the sight as well as of the hearing decreases and becomes obscure, the membranes of the eye contracting to the injury of their convexity. Everything is more languid, slow, and tepid than before. The internal senses are similarly decreasing, accommodating themselves exactly to the condition of the membranes which now are slack and Wrinkled; all this a proof that the veriest life of man begins to fade away as soon as the tremulation is in any manner prevented.
Compare now what has been said above with the life of the higher animals, and it will be seen still more plainly that tremulation makes the greater part of our living force, and, in fact, takes the role of nature itself in our life. Such animals as are born with the bony system perfectly developed, or nearly so, come quickly into the use of their full nature, as a native or innate thing. A chickened for instance, possesses most of the consistency of its whole skeleton when it is first hatched out of the egg; it can walk, it can see, it can hear, and move its wings and neck; in a word, everything within it is at once attuned for the reception of tremulation. There is, therefore, nothing dull With this little creature, but it runs at once into the full enjoyment of its very nature, without having to be nursed for any length of time. Of the greater animals, some attain their full growth in a few weeks, some in a few months, the largest in three or four years, after which their senses are developed as perfectly a~h us when we have reached adult age. Everywhere it may be seen how nature accommodates itself to the firmness or hardness of the nerves and the bones.
Now if the life of the senses were effected by any other means than tremulation by--some volatile force, for instance--why is it that this must still be connected with a hardness in the bones and the membranes, as a necessary condition? Could not this force flow through a soft substance, or liquid, just as well, or better, than through what is hard? Why must the hardness open the door and prepare the way? Or why should not the same way be just as open with the aged as with the young? It is not clear that much traversing must open the channels wider and wider, and that, therefore, according to such hupothesis, all the senses must be more wide awwake with the very aged? But as it has been shown that everything of life is accomadated to the stiffness and tension of the membranes and to the hardness of the bones, we cannot form any other conclusion than that of the sensories, which are amalogous to these parts, and that the tremulatory motion, by this means, displays its real nature in its greater or lesser degrees.
But lest any one should think that the senses thamselves might be fully developed with the new-born infant, and that he is simply unable to give an expression to his sensations, we will point to this wonderful fact, that the whole of that period during which the meninges, with all the other coats and membranes, are soft, is a period of oblivion, from which the infant is utterly unable to retain consiously the least impression for a subsequent period of life. Whatever may have been effected by the senses during infancy, seems to have been erased with the youth; the most important impressions and experiences, and the most common habits of life, recieved and attracted during infancy, and afterwards retained in the organs of the nerves as the very nature of the child--all this remains in the memory less consciously than a dream, although, as was said, nature still retains it in the sensories as the initiament of life. As an illustration let us consider only the faculty of speech. During the period of oblivion the organism of the mouth has been taught by a variety of things how to strain forth the sounds by different vibrations, and how to articulate the words; everything that the nurse has done for the infant remains with him, but the first efforts and the original habituations are afterwards forgotten. That which became a habit has now become nature itself, and it effects the speech in a moment without the least trace of the original effort. We may therefore conclude that all such things consist of most subtle tremulations which derive their life from the hardness and tension of the vessels and organs; but as soon as these qualities are lost, the recollection begins to vanish, as with the very aged and decrepit, and with others in whom the dura mater has become greatly disordered.
It is, indeed, most wonderful that a man excels all animals chiefly in this, that he reaches his maturity later than they, and that the very thing which may be accounted his imperfection is really the chief means for his perfection, and for his exaltation above all animals. Besides being gifted with a Soul in a reasonable understanding, we have been so ordered by God that all our membranes and bones must require a long period in order to become fixed and hard. In the meantime all our organs are disposed for the reception of ever new impressions, all of which require their time, until we have reached adult age. Hence also we may see what an advantage there is in our approaching slowly to our maturity, namely, that the understanding is able to increase and be more and more perfected, so as finally to present a man who can exhibit a ripe understanding, built up by a multitude of impressions and experiences. An animal, on the other hand, attains the full nature of its parents after a very short period; its membranes and bones become fixed in that nature which has been produced by the impressions of its entire breed or race, and there is soon an end to all further increase.
I know, however, that many may make this objection, that even those membranes which cover the soft parts, and which are not expanded like drums, are still able to cause sensations and to transmit tremulations; and that a tremulation in the bones can effect the same, when yet these possess nothing sensitive. But to this objection I would answer, that I do not at all mean to say that tremulation is distributed over a membrane merely as a membrane, but only in the degree that the membrane is expanded by a fluid; and, further, that a tremulation in the bones does not effect a sensation merely as a movement in the bones, but simply that the latter communicate a tension and a tightening to the periosteum and the membranes, and these, consequently, to the lymphatic canaliculi. For the first tremulation strikes the fluid part, the contiguity of which causes the motion to run over all that is fluid within all the membranes and meninges; and as there are continuous valvuli, it follows that the tremulation, while on the way, strikes against all of these, whence it is carried into the membranes, and so from the latter into the bones, in which a stiffness and hardness are necessarily required. For if there is nothing hard to contribute a tension to the membranes, it follows that the latter must remain slack and unstrung, whence the tremulation cannot run through the lymphatic canaliculi in any proper manner, but must pull and twist the membranes, to the hindrance of the communication. It may be seen from this what the hardness in the bones and the tension in the membranes contribute to the liveliness of the motion in the lymphatic system.
I. It is in the sense of hearing, above all other senses, that we may most advantageously observe the real nature of tremulation. All the organs and membranes connected with this sense are so prepared for the reception of this motion, and everything is so formed and arranged with cavities, bones, and turbinated, spiral passages, that the tremulation is excellently fitted to produce and communicate a sound or sensation in all that system which is included by the nerves and the bones.
Considering the anatomy of the organ of hearing, it will be observed, first, that nature has here created a channel through which the tremulatory air must flow, that is, in the curvatures of the external ear, which are able to gather in and concentrate a great deal of the tremulatory motion in order to bring about the better cooperation and cotremulation in the internal organ. Further in, this concentrated air is received by a bony canal, across which is placed a stiff membrane, known as the tympanum, or drum of the ear; the concentrated tremulations then strike against this membrane, effecting a vibration of the same kind as that which had taken place in the air outside the ear. Immediately within, or on the other side of this membrane, there is a cavity or meatus tympani, in which are placed the little bony bodies called the Malleus, the incus, and the stapes, each connected with one another by articulated joints, so that the motion and tremulation of the one must be communicated to the others. It is this malleus, or little hammer, which especially causes the tympanum to bend inward or outward, making the membrane stiff or slack, or more or less springy, as may be required by the necessary degree of the attention, or by the strength or softness of the sound.
The stapes, or stirrup, lies in a special space, by itself, together with two minute membranes expanded like a little drum, so that every vibration in the bones of the stapes is instantly communicated to this drum. For the further promotion of tremulatory sound there is also a labyrinth, or bony and turbinated passage, formed like a sea-shell, according to the nature of sound. The widest part of this passage, next to the base of the stapes, is called the vestibule, which also has a membrane of its own, of an oval figure, as its base. Up to this vestibule there run ten or twelve little foramina, through which run little threads or nervules, a part of which make the periosteum, the other part running on through the cochlea round about its walls; these nerves appropriate the sound and communicate it to the other periostea and membranes which are of the same root or contiguity. Behind the other part of the labyrinth, and opening into the vestibule, there are certain small, semicircular canals, bent about like horns or trumpets, which still more augment and concentrate the sound toward the interior part of the cochlea, after Which the tremulatlon flows on into other cavities and membranes.
From the whole anatomy of this origin we may thus know what kind of a mechanism the tremulation requires for its proper communication to the membranes, nerves, and bones in the body. The most important thing to observe is that the little membranes keep close to what is hard, and stand expanded over the air in the Concavities like little drums, whence the tremulation is communicated to other membranes; further, that the membranes weave themselves like the finest network about the bones, like musical strings over the bridge, and, like the bridges is fixed to the solid part of the instrument into which the tremulation must be carried, if there is to be any strength in the sound. The chief membrane in the mechanism of the ear is the one against which the tremulation strikes in the first instance, and injury to this membrane means injury to the whole organ of hearing. It will be observed that this membrane is joined to what is hard, and that it is derived from the periosteum of the skull; some suppose that one of its lamellae (for the tympanum itself is said to be double) is an extension of the dura mater itself, although, indeed, the periosteum of the skull has so close a communication with the dura mater that it may almost be counted as contiguous with it; we may thus see how this membrane connects itself with all that is hard round about. Within the cavity of the tympanum we find all the little bony bodies, the hammer, the anvil, etc., all of which appropriate the same tremulation and propel it further inward. The further it penetrates, the more little membranes does it meet; all of these are joined to their own bones as their periostea, which afterwards spread out into an expanse, and thus each membrane is endowed with its own solidity and hardness, as a bridge to which the tremulation may be carried beneath the stapes, and within the labyrinth, nay, everywhere within the petrous bone, there are wonderfully constructed cavities and cartilages, all surrounded with periostea and meninges, here and there extended over foramina, all of these being little harmonic skins or strings by which the sound is carried Into what is solid. The most subtle mechanism in the construction of the ear consists, therefore, in this, that all the membranes are periostea, so that these may be able to communicate their tremulation to the bones, and thus multiply and distribute the vibration.
2. the nature of tremulation as shown in the above, may be illustrated still further by many of the experiments which have been made in the art of music. It does, indeed, seem wonderful that so small a membrane as the one which closes the auditory meatus and which is expanded over the little pores and entrances to the bones and cartilages, is able to effect a tremulation throughout the entire solid system of the body, and that so small a fountain can produce so great a motion. But such is the nature which is peculiar to tremulation. What a commotion and distribution of sound is not. caused by the membranes of a battle-drum or kettle-drum, or by anything in which a membrane is expanded over a solid body! What a difference would there not be if the membranes were expanded over a soft substance ! They might be expanded to their utmost capacity, and still give but a dull sound, unless their edges were fixed to a hard or solid bottom. It is, therefore, the hardness alone, which, by its corresponding vibration, can contribute strength and distribution to the tremulation. Other vocal instruments show this still more plainly. The most rudimentary kind of a violin must have its bridge and must have its strings fixed at both ends to a solid body, in order that the corresponding tremulation in the body of the instrument may make the sound sharper, stronger, and more continuous.
Tremulation has this further peculiarity, that the least of its motions has the least regard for the mass or volume of the body in which it moves; it regards neither weight, nor hardness, nor grossness, but the contremiscences, as soon as they have originated, run like lightnings over the whole of that body which is subjected to them, while local motions, on the contrary, show respect and fear, as it were for heavy bodies. This is again illustrated in musical instruments. A string in a piano, when touched, at once sounds and plays its vibration over all that solid part with which it has a contiguity, thus permitting the tremulation to carry its reverberation to greater distances.
From this, also, we may see how small a cause is needed to produce too wide a distribution of the sound. Anything touching the body of an instrument, be it only by a single point of contact, is at once subjected to the tremulation in the instrument itself. If the instrument were in contact with a mast or any long pole, and if we were to put our ear to the other end, or touch it with our teeth, we would both feel and hear the tremulation which has been caused by a slight touch on the little string in the instrument. The tremulation is often endowed with a special sound from the nature of the place in which the instrument is; if there is a great rock below, one may at once notice that the sound is affected by the tremulation in the rock, something which deadens the usual sound in the bottom of the instrument; if there is a cupboard, box, or case in the room above the piano, the resonance must necessarily be increased hereby. All this shows that everything contiguous is set into a corresponding tremulation by the touch on the little string.
The increase of the sound is also affected by the quality of the material Which constitutes the bottom of the instrument; it is of one kind if the instrument is made of oak, another if made of spruce, cedar, etc.; the lighter and more porous the material, the heavier is the reverberation and the cotremulation. The tremulation is also subjected to great variations according to the varying thickness of the bottom of the instrument, or according to the hardness or softness of the wood, or its dryness and brittleness, or if it is close to some metallic object, or if the string is wound with horsehair or any other soft substance; all this a clear proof that the smallest membrane or string, Which is fixed to a solid substance by the two ends, is able to effect a corresponding tremulation in the most massive objects and to communicate the tremulatory motion to everything that is contiguous with it round about. If I should add Chapter VIII. to the present copy, you would see, from what I say there in respect to the distribution of tremulation, that the most minute vibration is able to permeate the greatest of bodies, even as the least contremiscence of a violin permeates the whole room where the music is performed. This is proved incontrovertibly by our own sensation, inasmuch as our hand can sensibly receive the tremulation by touching the wall of the room or the body of the instrument.
A few palpable illustrations may show still more plainly the reason why so small a cause can produce so great a flow of tremulations. In the shafts of mines one will see hanging great cables, weighted with hundreds of pounds; any small motion at the upper end, such as pulling it with the hand or striking it with a stick, will cause the whole cable to vibrate from one end to the others the tremulation flowing or undulating up and down with Swift serpentine motions such as may also be seen in the air or the water; the weight at the lower end is thereby lifted up and down, often with such a force as to cause danger to any one standing near, and yet the whole motion may have been produced by a rather insignificant cause. It may thus be seen that the tremulation or vibration has no regard for the weight below, and that the force increases mechanically according to the length or distance of the cable. Again, if a long rope is held by two persons and one of them pulls quickly at one ends even though with only a finger the other person will experience difficulty in retaining the other end. Or still better, a long rope, held horizontally, naturally hangs in something of a curve, similar to a parabola. Now in order to stretch this rope into a straight ones one needs a strong 'machine, and yet it will be impossible to stretch it so stiff that there will not always remain some invisible curve according to the length of the rope; a tremulation, passing along the ropes makes a continuous series of such Curves and as each one of these possesses its own mechanical force which counteracts the effort to stretch it into a straight one, and as these curves are swiftly passing on to the other end of the ropes we may not wonder that the impulse and the tremulation has increased in force when reaching its extremity. All this is one with the phenomenon which we observe in the little membranes of the body or the strings of the instrument, which when affixed to their solidities, give so great a force to the tremulation, that the hardest substance must partake of the tremulation, no matter what its size may be.
3. We may now be able to understand more clearly wherein the sensory in the ear consists, and how the tremulation is able to distribute its motion over the entire osseous and nervous systems from so small a beginning; all the membranes, which are intended for the distribution of the motion, are attuned and affixed to what is hard; the first, which is the membrane of the tympanum, is contiguous with the pericranium, so that the least tremulation in the tympanum effects a corresponding tremulation in the cranium and in the petrous bone; further in we find certain membranes which extend from the periostea over little cavities such as may be seen in the stapes in the fenestra ovalis and rotunda, and in the vestibule of the labyrinth, all of these being little tremulatory drums and cotremulating cartilages; still more interiorly we find wonderfully constructed rooms of cartilage and bone, all covered with little membranes which contribute their share to the tremulation of the entire systems; the use of the cavities is to carry the motion over to the other side and to effect a cotremulation in various places, so that the whole motion may spread with force over the membranes of the brain, the lymphatic canaliculi, the teguments of the nerves, and the bones. The sensory itself consists, therefore, probably in this, that the vibration presses in with force upon everything bony and membranous in the body, whence the communication of the tremulation throughout the system effects the sensation, and the sensation effects that which is perceived by us as a sound.
4. The same testimony is given by those sounds which enter the systems by ways different from those of the usual organs of hearing. First of all, it is to be observed that the sound itself does not reside in the membranes of the tympanum, a]one, but rather in the interior membranes, and especially in the dura mater and in the tremulation in the solid parts, and this without regard to the means or methods by which the motion has entered into the body. Any tearing of the dura mater, which may result from a blow on the head or from too great an exertion, is followed by a crashing sound or report as loud as if the head were between two cannons when being fired. When, therefore, the sound does not flow the usual way, nor touches the ordinary membranes, but originates further in the interior and thence sends a tremulation into the cartilages, bones, and nerves and membranes in the body--when we then seek to discover where the tearing or breakage has taken place, or where this interior sound has originated, we may find the cause far beyond the whole auditory canal; this has been established by the science of anatomy, from numerous cases. The sensory itself may therefore reside in whatever part of the cranium it pleases, provided only the tremulation is distributed over the same systems that are affected by the usual sound from without, through the external organ.
There are many other phenomena which show that the real sensory consists in the trermulation of the cranium. During a dream, for instance, we often carry on long conversations with imaginary persons, or we may hear whole melodies or other sounds which affect us exactly as those sounds which enter by the external way; when recollecting the dream during the following day, it seems altogether as if we had heard actual sounds. It is well known that the cerebellum (hjernan), while we are sleeping, is in a state of perpetual agitation; everything is in the effort to react and to restore itself to the proper order for the reception of a new motion and activity; an uninterrupted stream of tremulatlons is then flowing over all the systems, expanding everything and filling it anew with blood and fluids, mending, correcting, and restoring all that which has fallen into disorder by disharmonic tremulations during the preceding day. This, therefore, is a clear proof that sound is really an internal tremulation in the cranium and its membranes, and that it does not exist only in the little membranes of the cochlea and the labyrinth.
In fantastic imaginations, also, persons are able to hear various sounds and connected conversations, so that they sometimes persuade themselves that a spirit hem. I have spoken with them. I have spoken with a woman, who every day continually heard the singing of hymns within her, from the first to the last verses these hymns were often such as she herself had never heard or sung; she diligently sought help and cure from clergy men and others, but in vain, for the melodies and songs continued in the brain as if she were perpetually at tending a great concert. Does not this show that the sensory of hearing consists essentially in internal tremulations in the cranium, which are able to extend themselves to the ordinary organ of hearing if only there be a similar motion in the matres. A singing or ringing sound is also noticeable in the ear, when the matres or membranes are diffused and greatly distended with blood by the arteries, whence the tremulation is unduly hastened over everything contiguous.
The contrary takes place when the internal membranes become more thick or slack, as when the arteries are dry or when the blood has escaped from the most minute vessels, thereby causing a pallor on the surface, as takes place in a state of fear and by various accidents and diseases, when neither the external nor the internal membranes are able to receive the tremulation and still less to carry it round about. For a slackening of the membranes must necessarily cause a letting back or regurgitation in all the lymphatic vessels, so that when a tremulation then enters the most minute of the canals, it finds the membranes slack and wrinkled and thus obstructing the communication.
Other phenomena show still more plainly that the sound or hearing is caused by the tremulation in the cranium and its membranes; a vibration in any one of the bones of the cranium immediately produces a sound within which is also perceived as sound by the external ear, and this on account of the close communication that exists between the tympanum and the pericranium. If, again, the vibration enters immediately by means of the teeth, especially those of the lower jaw, it will similarly flow into the cranium and there produce the perception of sound; for the ramifications of the auditory nerve extend not only to the organ of hearing, but also to the periosteum which surrounds the roots of the teeth; one branch, which is soft, goes to the cochlea and makes the membrane of the restibulum, whence arise a number of other membranes in the semicircular canals, etc.; the other branch, Which is hard, runs to the tympanum, as also to the tongue and the teeth; branches from the first and the second cervical nerve run also to the mouth and to the teeth, so that the tremulation flows to and fro as on minute bridges, finally arriving at the cartilages and membranes in the petrous bone, and hence round about the whole cranium and all its systems.
5. If we closely examine wherein the tremulation of sounds differs from other tremulations, we will find that the former flows with greater swiftness and force over all the bones and membranes than do any other tremulations, just as when one bends a string firmly, drawing it into a curve for a broad tremulation, whence the sound becomes stronger than if the vibration is moving more close]y around its centre; if we strike anything that is expanded in the air, we will produce a stronget sound than if we strike what lies close to something solid. To effect a sound in the organ of hearing, there is needed, therefore, the following mechanism: a, the dura mater is expanded directly over the cerebrum and exposed for the reception of tremulation, whence any impulse on the dura mater immediately effects a tremulation; b, the membranes are in various places affixed to the cranium, the better to arrange for the concert and to give sufficient initiative to the sound; c, there are also a number of cavities or vacuities which permit the little membranes to play with their tremulation without the hindrance of anything that is soft; moreover, there are, in the cranium, an infinite number of porosities of such a kind as are required by the tremulation in any solid substance. The auditory part of our living organism consists, therefore, of stronger tremulations than are found in the other parts, as shall be shown further in what follows; the difference consisting not only in the swiftness of the motion, but also in the degree of the tremulation.
It will now be necessary to make a summary conclusion of all that has been shown above, and to state briefly wherein sensation essentially consists, as otherwise one argument may prevent the correct comprehension of the other. The case is therefore as follows:
The first motion or tremulation takes place in the fluid which is distributed over all the membranes, and which flows through all the lymphatic ducts, thus creating the inmost contiguity within the body; the least impulse on this fluid effects a tremulation which flows over the whole of this contiguity, with all its membranes, meninges, etc. The secondary or corresponding cotremulation is therefore the one which takes place in the membranes, and the third is the one that takes place in the bony system which is so closely connected with the membranes. From all this it follows, first, that if the fluid is absent, there can be no impelling force for the motion or for its communication to the membranous system, as may be seen in cases of apoplexy or swooning; secondly, the sanguineous fluid, if too abundant, causes the lymphatic canals to be too greatly expanded they become dammed up in certain places, or are pressed to and fro, whence the tremulatory motions are obstructed and forced to seek various side paths, making extraordinary vibrations in the place of the proper ones, as may be seen in cases of sudden passion, or in drunkards; thirdly, an insufficiency of the sanguineous fluid causes the lymphatic canals to lie slack and flat in many places, making uneven openings for the lymph, which is thus deprived of its proper sensation, as may be seen in cases of exhaustion, fear, etc.; fourth, if the membranes are too slack, and hence wrinkled or twisted, it follows that the tremulatory fluid cannot flow forward in a proper manner, but the tremulation becomes dull or has altogether ceased before it has arrived at its terminus; fifth, if the bones are not in their proper condition, it follows that the membranes cannot be well expanded, or the lymphatic canals properly extended and open, but certain membranes must here and there fail to assist the course of the tremulation.
The summary of the whole is therefore this, that when the membranes lie well expanded towards their bones, and when the blood-vessels possess an even tension, then can everything that is fluid pass freely through all its vessels and have a contiguity throughout all the systems, so that the least impression in any place makes an impression upon all that is fluid. A vibration is thus communicated to the little valves in the vessels; a corresponding tremulation is hence imparted to the membranes, and through the latter, finally, to the bones and thus, as soon as the tremulation has been communicated to everything that is expanded and contiguous in the whole body, there results from all this what is termed a sensation. Quad erat demonstrandum.
It is, indeed, wonderful what a power there is in a fluid to communicate a corresponding cotremulation to a hard substance. A tremulation in the air imparts a similar motion to the whole organ of hearing, with all its cartilages and bones. A small bomb exploded under water, causes a tremulation in the ground and the rocks round about, just as the fluids in the body communicate their tremulation to all the membranes and bones, in order to produce all that is moving and living in a man.