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 extramarginally 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.

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 diviningring 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 realised 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 realise 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.

LETTER XIV.

HYPNOTISM. TRANCE-UMBRA.-Mr Braid's discovery-Trance-faculties manifested in the waking state-Self-induced waking clairvoyance -Conclusion.

It is an advantage attending a long and patient analysis of, and cautious theorising upon, a new subject of inquiry, that when fresh facts and principles emerge in it, instead of disturbing such solid work as I have supposed, they but enrich and strengthen it, and find, as it were, prepared for them appropriate niches. Something of this satisfaction I experience, when I have to render tardy justice to Mr Braid's discovery, and to give an account of the wonders realised by Dr Darling, Mr Lewis, and others.

Or, I have observed, that trance, considered in reference to its production, has a twofold character. It presents itself either as a spontaneous seizure brought on unsuspectedly by a continuance of mental or physical excitement or exhaustion; or as intentionally induced through the systematic direction by some second person, more or less cognisant what definite effects he can produce, of certain moral and physical influences upon the party intended to be wrought on. Mr Braid has added a third causal difference to the theory of trance. He has shown that trance can be induced by the subject of

it himself voluntarily, by the use of certain means, which call into operation a special principle. The effects which he obtained by these means, but which he perhaps studied too much to separate from the effects of mesmerism-these and their principle he denominated Hypno

tism.

Again, I have shown that all the forms of trance may be, and require to be, arranged under five types-viz., death-trance, trance-coma, initial trance, half-waking trance, full-waking trance. I mentioned, besides, that in the manifestation of Zschokke's seer-gift, and in the accounts which we receive of the performances called second-sight, the extended exoneural perception was introduced by a brief period, in which the performer was in a degree absorbed and lost, yet did not pass on into a second and separate phase of consciousness. He was still always himself, and observed and remembered as parts of his natural order of recollections the impressions which then occurred to him. This same state must be that which I have seen described as one peculiarly suited to the exhibition of phreno-mesmerism. Mr Braid appears likewise often to have brought it on in his curative applications of hypnotism. But now it has new importance and distinctness conferred upon it, as being the state in which the wonderful phenomena of "mental suggestion" are best displayed, and in which conscious clairvoyance is manifested. As this state does not amount to complete trance, but as it is a foreshadowing of it, as it were, I venture to propose for it the name of trance-umbra.

I. Hypnotism.- Mr Braid discovered that if certain sensitive persons fix their sight steadily upon a small bright object, held near and above the forehead, or their sight becoming fatigued, and the eyelids fall, if they keep