The present letter might be entitled “An account of some motions recently discovered, to the manifestation of which an influence proceeding from the living human body is necessary.” The contrivance by which these motions are elicited I have called an Odometer, from the conviction that the force which sets it in movement is no other than the Od-force of Von Reichenbach. For the same reason I have called the objects with which it is tested Od-subjects, and the motions themselves Od-motions.

The odometer is a pendulum, formed of a ring, or other small body attached to a thread, the other end of which is wound round a finger or the thumb. The odometer employed in the following experiments was a light gold ring, having a greater mass of metal on the unattached side, and suspended to the last joint of the right forefinger, the suspending medium being either silk, or fine cotton, or the hair of a horse. The experiments were made by myself. In order to avoid the confusion resulting from a multiplicity of details, I shall state the results obtained through testing a limited number only of Od-subjects, so selected as to represent the leading divisions of the provinces of nature, and of dynamics. With some of the principal the reader will be already acquainted through Letter XII., the contents of which will have prepared him for, and probably suggested to him, the following question, as a desirable subject of preliminary consideration.

I. Are the motions referred to worth examining at all? Are they more than the simple results of impulses conveyed to the pendulum by movements of the hand or wrist, or some general sway of the experimenter’s person, unintentionally going with the expectation or conception of this or that motion of the ring? Such a solution of the phenomena is not wanting in probability. It is metaphysically and physically certain, that when we maintain one and the same bodily posture or gesture, as in standing, sitting, or holding out the hand, whatever be the seeming continuousness and unity of the effort, the posture or gesture is really maintained only by a series of rapidly succeeding efforts. What is more likely than that, in such a continual renewing of voluntary actions, our fancy, or the sympathy between our will and our thoughts, should give a bias to the results, even when we most try to neutralize its influence? The fact which I propose first to mention is in complete agreement with this view. I can at will cause the odometer to move exactly as I please. Although I hold my hand as steadily as possible by leaning the arm against a table, and endeavour to keep my person absolutely still, yet I have only to form a vivid conception of a new path for the odometer, and a motion in the so-imagined direction is almost immediately substituted for that which was before going on. In like manner, I have only to conceive the cessation of motion, and the odometer gradually stops. I must farther admit that my first trials of the odometer were made under the full expectation that the results which ensued would follow. And I cannot say that it is impossible, that when other and new motions emerged, they were not often either realizations of a previous guess, or repetitions on the same principle of what occurred at first as an accident.

On the other hand, I am not unprepared with an array of facts which seem to me capable not only of neutralizing the force of the preceding argument, but of making it appear, most likely, that some other influence than that of the experimenter’s mind is often in operation in bringing about these results; an influence sufficiently curious, as I think, to justify me in continuing this investigation and the present letter. I beg the reader’s candid construction of the following statements.

If, when trying the odometer, I have caused it, by conceiving a different motion, to change its path and move in a wrong direction, I now endeavour to divert my mind from considering its motion at all, the odometer invariably resumes its previous right movement. It is, indeed, difficult to observe a strict mental neutrality in this instance. For the odometer moves imperfectly and uncertainly, unless I frequently look at its performance. Or, as I interpret the fact, unless I keep my attention fixed to a certain extent on what I am doing, my hand loses its steadiness, and communicates all sorts of distracting impulses to the pendulum. And the uncertainty hence arising admits, it appears to me, of being obviated by the comparison of numerous careful repetitions of the experiments.

Many of the motions which I at first thought were genuine Od-results, I afterwards found out I had been mistaken in. And the correction of these errors was mostly due to frequent and careful repetitions of the experiments, unattended by an expectation of finding the results reversed or otherwise modified, and instituted simply to secure their genuineness and certainty.

Then there was one result which at one time I confidently anticipated; but it never came up. I had found the ring make gyrations in the direction of those of the hands of a watch, when held over the small end of a living unincubated egg. Opposite gyrations were obtained over the big end. I thought this might have to do with the sex of the embryo. And I tried, accordingly, a dozen eggs, expecting that in some the direction of the gyrations at the two ends would be reversed. But this event never occurred, much as I laid myself out for it. If my fancy could have decided the matter in spite of my care to prevent its interference, I am clear that for a time, at least, I should have obtained in these experiments upon the egg a double set of results. I was much delighted two months later at coming upon the explanation of the question, why gyration like that of the hands of a watch is manifested at the little end of the egg. I had known from nearly the first that this direction of the rotatory Od-motion is manifested when the pendulum is swung over the right side of the human body. Then I fell upon an old physiological reminiscence, (and found a drawing of the fact in my outlines of Physiology,) that the embryo chick lies in the egg transversely upon its face, with its right side towards the little end.

Then there were two other results, which were directly at variance with my anticipations, but which never failed to present themselves. I made a voltaic arrangement by means of two plates, one of zinc, the other of copper, fixed in contact in a solution of salt in water. Now, when held opposite the middle of the zinc disc, the odometer always rotated like the hands of a watch; while over the copper disc the phenomenon was reversed. These results are constant. But I have had the satisfaction of lately discovering that, if I present the ring to any part of the circumference of the two discs, its motion is the opposite, and in accordance with theory.

One of the tests on which I have much relied in determining whether the motions I obtained were genuine Od-motions, consisted in producing their reversal by altering the Od-relations of my hand or of my person. What gives particular value to this test is, that the versed or complimentary motion is subject to different laws. One set of secondary oscillations changes into oscillations in a plane at right angles to the plane of the primary oscillations. In another series the motion continues in the same plane; but the excursions, which were before longest in one direction, are now longest in the opposite, as if a repellent current had been substituted for an attracting one. The Od-oscillations, it may be observed, are always dependent upon the action of a constant rectilinear force counteracted by the gravitation of the pendulum. The means I usually employ to reverse the primary Od-motions is, bringing the end of the right thumb into contact with the odometer-finger, where the thread is wound round it. But the experimenter cannot be too careful not to bring the thumb even near to the odometer finger, or to allow his other fingers to close upon the ball of the thumb, for the phenomena are thus again liable to be reversed.

The other means of reversing the results of the experiments are:—

The various substances employed as Od-subjects admit of being divided into two great classes; one consisting of unorganized or organized bodies in which a minimum of internal activity is present; the other, of bodies of both classes, in which the more energetic properties of matter are at work.

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I. Let me first notice the results obtained with the first class of bodies. These, again, are reducible to two forms. The Od-subject may either be of a regular figure and equal thickness throughout—as a piece of money, for instance; or it may be of an irregular figure, with an unequal mass of matter at one part—as, for instance, when it consists of an aggregate of several pieces of money variously arranged. I shall first treat of the first and simpler case.

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It does not matter how you face in making these experiments. The influence of your person makes the various meridians of the Od-subject. The movements which we have first to examine are the results of holding the odometer over the middle of various uniform discs, such as I have supposed. They consist of two series of oscillations—one directed longitudinally to and from the experimenter; the other transversal, or in a plane at right angles to the plane of the first series of oscillations. Then it is highly convenient to have terms denoting the four cardinal points at which these oscillations cut the edge of the circular disc. These points may be termed distal, proximal, dextral, sinistral. It will likewise be found convenient to have terms to denote the direction of the motions manifested. The terms distad, proximad, dextrad, sinistrad, will serve our purpose. These terms refer to the person of the experimenter. Two other terms are still wanting; sometimes rotatory motion supervenes, which maybe either in the direction of the motion of the hands of a watch, or the reverse. I call the first of these two motions clock-rotation, the second versed-rotation.

The present class of Od-subjects present the following remarkable differences among themselves:—

Over one class, including gold, zinc, and polished glass, a circular mass of bicarbonate of soda, the odometer primarily oscillates longitudinally.

With the other class, which includes pearl, ground glass, copper, a circular mass of tartaric acid, the odometer held over the centre primarily oscillates transversely.

Over polished glass, an odometer of resin oscillates transversely; over ground glass longitudinally.

Each of these movements is replaced by the other, when the thumb is brought into contact with the odometer-finger. (See figs. 1 and 2, in which the continuous line represents the primary motion; the dotted line, the secondary or complementary or reversed motion.)

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II. Analysis of the forces, or currents conducing to, or implicated in the movements of the odometer just described.

It has been said that the above movements manifest themselves when the odometer is held over the centre of the Od-subject. Let us now examine the consequences of holding the odometer extra-marginally to, or beyond the edge of, the Od-subject.

a. Let the odometer be held a quarter of an inch away from, and over each cardinal point of a sovereign, or zinc circular disc, in succession. Result—Held near the distal point, its motion is proximad. Held near the proximal point, its motion is proximad. Held near the dextral point, its motion is sinistrad. Held near the sinistral point, its motion is sinistrad. (See fig. 3.)

But the first two impulses thus attained correspond with the direction of the primary oscillations of the odometer, the last two with its complementary oscillations; and if the odometer be held now over different points in succession of the two diametral lines, suspended, of course, by the finger alone over the first series of points, and by the finger touched by the thumb over the second, it will be found that the primary oscillations originated over every point of the longitudinal diameter of the zinc disc are proximad; and that those obtainable over any part of the transverse diameter of the zinc disc are sinistrad.

Then the forces or currents are made manifest by which the two sets of oscillations are produced; and the marvel of the prompt substitution of one for the other is at an end; for it is evident that these two forces, whether produced or only revealed by the presence of the odometer, co-exist; and that the changed Od-relations of the experimenter to the odometer, (effected by disjoining the thumb from, or joining it to, the forefinger,) simply act by giving temporary predominance to one of the two co-existent currents.

If these experiments be made at the edge of the copper disc, they elicit opposite but parallel results. (See fig. 4.) They evince the existence of two currents, one dextrad, the other sinistrad, from which the same conclusions may be deduced.

It is important to notice, that in all this class of the experiments, the distad and dextrad currents are manifested in combination; and in like manner the proximad and sinistrad.

This combination is further exemplified in the next experiment, which I shall describe.

We cannot, however, suppose these extra-marginal tangential motions to be the lateral limits of the four great currents, inasmuch as they are obtained by the versed process to that which obtains the central motion; and the question arises, what then are the limits of the central currents?

This second result establishes that the longitudinal proximad current extends laterally to the edges of the disc; but that, when near to them, the force of the co-existing transverse current asserts itself, driving the odometer (on the left) off in a sinistro-proximad diagonal, which ends in the establishment of clock-rotation; on the right driving the central current off, in a dextro-proximad diagonal, resulting in versed rotation. (See fig. 7.)

Parallel and opposite results are obtained by the odometer when these experiments are repeated with the copper disc; and necessarily the clock-rotation appears near the proximad margin of the disc, the versed rotation near the distal edge.

Therefore it is evident that the great longitudinal and transverse currents extend over the whole disc, but not beyond it. Experiment a, section II., and figs. 3 and 4, show that, immediately beyond the cardinal points, single forces are in operation.

Other interesting results follow from trying with the odometer the extra-marginal spaces between the cardinal points.

Fig. 10 gives the corresponding, but opposite, results obtained upon the copper disc.

It is, however, doubtful whether these currents traverse the whole disc. For if the experiment is made of following each upon the disc, their influence disappears at less than a quarter of the diameter, where the odometer is found to obey on the zinc disc the proximad current, on the copper disc the dextrad current. Or, probably, these currents are the simple expression of the action of two equal forces moving the body operated on by them (at right angles to each other) in the diagonal. These effects thus form a remarkable contrast with the results given in figs. 7 and 8, wherein rotatory movements are manifested; and they seem to show that an essential element in these rotatory movements is, that one of the two currents acting on the odometer must, in the latter case, be of superior force to the other.

III. Motions of the odometer obtained over the same class of substances, when of irregular figure and unequal thickness.

Thus a force is brought into view having this new quality: when the Od-relations of the experimenter are versed, a change ensues, not into motion in a plane transverse to the former one, but the direction of the new motion is simply the opposite of the first, or the odometer appears to be attracted or repelled towards the Od-subject alternately.

Then an irregular form of the Od-subject, or its unequal mass at different parts, have nothing to do with this new motion; and it is evident that the relation of the latter to the former class of oscillatory motions will be easily determinable.

When the same experiments are made on the left edge of the Od-subject, phenomena just the reverse are manifested for the same distance. The extra-marginal dextrad motion is transverse for an inch and a half. Then there occurs a point of quiescence; on the other side of which the odometer swings in free and long sinistrad or repelled oscillations.

Effects parallel to these are attained at each of the cardinal and inter-cardinal points of the whole circumference, upon the zinc or copper disc, but as usual always reversed.

Opposite to the eight intervening spaces, the character of the remote motion is changed. There it is a rotatory motion in a direction the reverse of the rotatory motion shown in figs. 15 and 16.

Thus, there exists all round the disc, at a distance of about an inch and a half, a circle of complete repose. Within this the proper, or near, extra-marginal movements of the odometer are manifested: without it, the motions of the second and remote force last described.

But to return to the facts mentioned at the beginning of this section.

The movements of the odometer over a line of sovereigns, or from a distance towards its centre of gravity, are evidently the consequences of this remote force coming into operation; the long and forcible oscillations caused by which toward or from a remote point override the smaller near extra-marginal, and the super-discal forces of the Od-subject.

IV. I have next to deal with the effects obtained by trying the odometer with mineral bodies, in which electric, chemical, or magnetic forces are energizing, or that force on which crystalline structure depends, and with organized bodies in possession of life.

In this section, I propose to describe the simple resultants, analogous to the two diametral movements, obtained when the odometer is held over a sovereign. It will be remembered that, of these two, one only manifested itself at a time; and that their meridians were determined by the person of the experimenter. One movement was either in the direction of the mesial plane of his person, or in one parallel to it—namely, the longitudinal oscillations; the other was in a plane at right angles to the first.

The corresponding movements of the odometer with the class of bodies now to be considered are rotatory; and two, at least, are always simultaneously manifested—one a clock rotation, the other a versed rotation. These opposite rotations are likewise always manifested on opposite sides or opposite ends of the Od-subject, indicating the development of polarity. Finally, the force of this polarity is such as to render the influence of the person of the experimenter nugatory as to the direction of the forces. Accordingly, if a horse-shoe magnet is laid in any position in reference to the experimenter, clock-rotation is always obtained by holding the odometer half an inch above, and beyond its northward pole; and versed rotation is invariably obtained in like manner at its southward pole. The effect of touching the odometer-finger with the thumb is exactly to reverse the two rotations.

I will now describe the individual instances in which these rotations are manifested; or the parts of each Od-subject over which the odometer rotates in opposite directions.

The last holds likewise with the greater part of the human body; but the results of trying the odometer with the human frame are so complicated, that I shall reserve their consideration for a separate section.

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V. The mechanical solution of these phenomena is simple enough. The odometer must be under the influence of two constant and unequal rectilinear forces, operating at right angles to each other on the gold ring, the effects of which are modified by the centripetal force of its gravitation. All that is required is, to determine by observation the place, direction, and limits of the two forces.

It will render the description which follows easier, to suppose that the pole of the Od-subject which causes clock-rotation be turned directly from the experimenter; for example, that an egg be placed longways to the experimenter with its small end from him, or a bar magnet with its northward pole from him. In the case of a horse-shoe magnet, both poles are then turned from you. So, too, in the case of the hand, the fingers and thumbs are both to be turned away.

The effects described are given in fig. 17. Then here are, at either end of the egg, two rectilinear currents acting at right angles to each other. Fig. 18 represents the complementary motions to the above, which are obtained by touching the odometer finger with the thumb. A parallel combination of rectilinear motions is produced, but in another way.

The next three figures exemplify the composition of forces necessary to produce the rotatory motion of the odometer.

Figs. 19 and 20 are intended to represent the large ends of two eggs, so placed that the axial currents of the two shall cross at right angles, at a point equidistant, let us say at half an inch exactly, from the end of each egg. If the ring be suspended exactly at the point of meeting of the two forces, it will be driven off in the diagonal, and continue simply to oscillate in the line A B. But if either of the eggs is moved back to double its former distance from the point of intersection of the two forces, the forces will be rendered unequal, and new results will ensue. The two experiments by which the results of this arrangement may be tried are represented in figs. 21, 22, and figs. 23, 24. The longer current is necessarily thereby the weaker of the two in each combination. Accordingly, rotatory motion supervenes in each case instead of diagonal oscillation; and the direction of the rotation is from the stronger towards the weaker current.

Figure 25 represents the various motions which may be elicited by holding the odometer at the sides or over different parts of a horse-shoe magnet. The continued lines in all the diagrams represent the primary motions, the dotted lines their complementary motions.

Figures 26 and 27 represent, in the same way, the primary and secondary oscillations obtainable over the centre of, or parallel to the needle.

Figures 28 and 29 represent the motions displayed by the odometer, when it is held above various points in the interval between two sovereigns, placed upon the table an inch and a half asunder. Compound effects follow, produced by the joint influence of the two bodies.

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VI. I will finally describe the phenomena elicited by the odometer from the living human frame, including those which are dependent on difference of sex.

Parties to experiments with the odometer may be in the position either of Od-subjects, or of reversers of its effects in the hands of others, or they may be themselves components of the odometer.

I can discover absolutely no difference in the results obtained by the odometer on men and women, when treated as Od-subjects. The following results appear to me equally obtainable with persons of both sexes.

With the exception of the arms below the elbows, the wrists and hands, and of the legs below the knees, the ankles and feet, the two sides of the person display the polar differences already noticed. If the odometer be held over the right side of the head, (either front or back,) over the right side of the face, over the right shoulder or elbow, or right knee, it exhibits clock-rotation. Held over the same parts on the left side, it exhibits versed-rotation. On touching the odometer-finger with the thumb, these effects are of course reversed.

If the odometer be held over the middle and outside of either arm, or over the middle and back of either fore-arm or hand, it oscillates longitudinally and towards the hand or foot. On reapplying the thumb, these longitudinal oscillations are replaced by transverse oscillations, having a direction outwards—i. e., away from the mesial plane of the frame.

The phenomena last described show that the primary idea of a transverse polarity for the whole frame is still verifiable, even in the extreme parts of either limb. But below the elbows and knees a second polarity is superinduced upon the former. Below the elbows and knees, one side of each limb repeats the phenomena of the right side of the body, the other those of the left. The odometer held over the tips of the fingers of either hand exhibits clock-rotation, over the thumb of either hand versed-rotation; and with these, as I have mentioned, all the other effects that can be elicited out of the two limbs of a horse-shoe magnet. The same rotatory movements may likewise be obtained by holding the odometer near the two edges of the hand, wrist, fore-arm. The latter singularity, which contrasts with the simpler effects on the upper arm, must result from the combination of the two polarities—the systemic and the submembral one.

The odometer, held over the back of the neck or throat, oscillates transversely. When versed, longitudinally.

It appears to me now that women generally are incapable of eliciting the movements of the odometer when held by themselves, without touching a second party.

I have already, in the introductory part of this letter, given a summary of all the modes I am acquainted with of reversing the motions of the odometer.

Perhaps I have presumed too much in heading this letter with the title of “The Solution.” But what is the solution of physical phenomena but the displaying of the forces which compel their sequence? As an inquiry progresses, a few general expressions take the place of the first imperfect and complicated explanation. But the first step made was still a solution; and the highest solution ever yet obtained has probably still to be merged in some expression yet more general. So the attraction of gravitation is probably connected with, or balanced by, a corresponding repulsive force, coming into operation at some enormous distance from the centre of each planetary sphere, and the two may eventually prove to form one law.

But I had hoped that I was not presuming in asserting that the present inquiry has immediate practical applications, such as seldom fall to the lot of so young an investigation. The odometer may prove a useful test of the presence and qualities of electric, chemical, and magnetic actions; it will probably help to determine the electrochemical qualities of bodies; and in large or small crystalline masses—in the diamond, for instance—will serve to show the axes and distinguish the opposite poles. In reference to biology, it will probably furnish the long-wanted criterion between death and apparent death; for I observe that, with an egg long kept, but still alive, though no longer likely to be very palatable, the odometer freely moves in the way described in the fourth section. But it treats the freshest egg, when boiled, as if it were a lump of zinc.

Nevertheless I am not without certain misgivings. I suspect that the divining-ring will be found to manifest genuine Od-motions in the hands of as small a number as succeed with the divining-rod. And I fear that overhasty confidence in results only seemingly sound, may lead many astray into a wide field of self-deception.

POSTSCRIPT.

An accident has given me the opportunity of making further additions to this little volume, of which I proceed to avail myself; and, first, by communicating my latest experiments with the divining-ring, July 24.

I. I have stated that, if a fresh egg be placed upon the table, with the small end directed from me—or a crystal, with one definite pole so turned from me—or a bar-magnet, with its northward pole so disposed—and I then suspend the divining-ring half an inch above either of the three so averted ends, and half an inch further off from me, the ring exhibits clock-rotation in each instance. Held in a parallel manner over the opposite ends—that is, half an inch from, and half an inch higher than, the same—the ring exhibits versed-rotation. If the three Od-subjects be moved round, so that their hitherto distal ends point to the right, or if they be further turned, so as to bring the previously distal ends now to point directly towards me, the ring continues to exhibit exactly the same motions as in the first instance.

If, these objects being removed, I lay a horse-shoe magnet on the table before me, with its poles turned directly from me, the northward limb being on my left hand, the southward limb-pole on my right, and experiments parallel to those just described are made, the results remain the same. If, near one side of the horse-shoe magnet, I lay my left hand on the table, the palm downwards, the thumb held wide of the fingers, the ring, if suspended half an inch from and above either of the finger-points, displays clock-rotation; suspended similarly before and above the point of the thumb, versed-rotation. Or the fingers of the left hand, so disposed, may be compared, in reference to Od, to the northward pole of a horse-shoe magnet, while the thumb corresponds with its southward pole.

If, removing my left hand, I turn the horse-shoe magnet, without altering the side on which it rests, half round, so that the poles point directly towards me, the northward pole being now, of course, on my right, the southward pole on my left, the ring held as before over either of the two poles, displays the same results. If I now move the magnet still nearer to me, so that its two poles are an inch beyond the edge of the table, I can obtain results which furnish a more precise explanation of the two rotatory movements already described, than I had before arrived at.

If I now suspend the ring, with its lowest part on a level with the magnet, and half an inch from its northward pole—that is, half an inch nearer me—it begins to oscillate longitudinally, with a bias towards me, as if it were repelled from the pole of the magnet. If I then suspend the ring an inch vertically above the first point of suspension, it begins to oscillate transversely, with a bias towards the right, or as if impelled by a dextrad current. If I then lower the ring half an inch, the first effect observed is, that it oscillates obliquely, being evidently impelled at once to the right and towards me—that is, in the diagonal of the two forces, of each of which I had before obtained the separate influence. In this third variation of the experiments, I have brought the ring to the limit of the two currents, where both tell upon it. This oblique oscillation soon, however, undergoes a change: it changes into clock-rotation, showing that the transverse or dextrad current is stronger than the longitudinal or proximad current.

If parallel experiments be made at levels below that of the pole of the magnet, corresponding but opposite results ensue. If the whole series be repeated upon the south pole of the magnet, opposite but perfectly corresponding results are again obtained: and similar results may be obtained with the two poles of an egg.

II. The mode in which I have latterly educed the rotatory movements depending upon galvanism, has been this. I have laid two discs, one of zinc, the other of copper, one on the other, having previously moistened their surfaces with salt and water. Then, as I mentioned, the ring held over the middle of the zinc disc (that being uppermost) exhibits clock-rotation. Held over the middle of the copper disc, when that is laid uppermost, versed-rotation. I mentioned, too, that if held beyond, but near the circumference of the same discs, the direction of the motion of the ring is reversed.

The discs which I employ are circular, an inch and a half in diameter, and about as thick as a sovereign. Upon these I do not fail to obtain, when dried and used singly, the first series of phenomena described in the preceding letter. But it occurred to me to try what would be the result of suspending the ring over the two together, and alternately laid uppermost, when they had been well cleaned and dried. This is evidently a still simpler voltaic arrangement than when the salt and water is additionally used. The result was in the highest degree interesting. When I suspend the ring half an inch above the centre of the copper disc, (that being laid uppermost,) the first motion observed is transverse; but after a few oscillations it becomes oblique—dextrad and proximad combined, in the diagonal between the primary influences of the zinc and of the copper. This change does not last long; the transverse force again carries it, in this instance, and clock-rotation is permanently established. When the zinc is uppermost, the corresponding opposite phenomena manifest themselves; and in either case a reversed movement occurs, if the ring is held extra-marginally to the discs.

III. I may say that I have now obtained positive evidence that these motions of the odometer do not depend upon my own will, or the sympathy of my will with existing conceptions in my mind; for they succeed nearly equally well when the discs are covered with half a sheet of writing-paper. In nine cases out of ten, when I thus manage to be in perfect ignorance which disc, or what combination of the two, is submitted to the odometer, the right results manifest themselves, and the cause of the occasional failures is generally obvious. Let me add upon this topic, that one day, the weather being cold and wet, and myself suffering severely with rheumatism, the odometer would not move at all in my hand. On another day, late in the evening it was, when I happened to be much fatigued and exhausted, the ring moved, indeed, but every motion was exactly reversed; thus my left hand I found now obtained exactly the results which, on other occasions, I got with the right.

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IV. But by what cause, then—through what mechanism, so to speak, are the movements of the odometer immediately produced? Early in the inquiry I made this experiment. Instead of winding the free end of the silk round my finger, I wound it round a cedar-pencil, and laid the latter upon the backs of two books, which were made to stand on their edges, four inches apart, with the Od-subject on the table between them, the ring being suspended half an inch above it. The ring, of course, remained stationary. Then I took hold of the pencil with my finger and thumb, at the point where the silk was wound round it; my finger and thumb rested on the silk; but no motion of the odometer ensued. Hence it follows, that the odometer is, after all, always set in motion by the play of my own muscles. I venture then to suppose that my sentient nerves, unknown to me, detect on these occasions certain relations of matter—let me call them currents of force—which determine in me reflexly certain sympathetic motions of the very lightest, and even of an unconscious character. This idea, which I am sure affords the just solution of the matter, is highly consistent with some observations which I have before recounted. It explains how the primary delicate impression should yield to the coarser influence of a strong conception in the mind, that this or that other motion of the ring is about to follow, or even to that of a vivid and, so to say, abstract conception of another motion. It explains what I have several times verified, that on certain days a person standing behind me with his hand on my ear, or on my shoulder, can, by an effort of his will (mine not resisting,) make the odometer which I am holding move whichever way he happens strongly to image to himself, without communicating the same to me. It explains to me on what the difference consists between those who can set the divining-ring in motion, without a conscious effort, and those who cannot. The former, it will be found, are persons of so great nervous mobility, that any such motions, if their occurrence be forcibly anticipated by them, will certainly be realized by their sympathetic frames. Among this class should be sought, and would still remain to be detected by experiment, those whose impressionability by Od should prove commensurate with their nervous mobility. Finally, I cannot doubt that the view which I have thus arrived at respecting the mechanism of the motions of the odometer, is equally applicable to the explanation of those of the divining-rod. I see that, through its means, many before anomalous facts, with the narrative of which I have not bored the reader, which emerged in my former trials of the divining rod, made by the hands of others, lose their obscurity and contradictoriness, and leave the whole subject in the condition of an intelligible and luminous conception.

N. B.—It is a pity that of the inquirers who now amuse themselves with investigating these subjects, very few realize in their minds the idea of Von Reichenbach, that Od, though often exhibiting the same relations with electricity and magnetism, is yet an utterly different principle.

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