30 JANUARY 1869, Page 9

THE HYPOTHESIS OF BRAIN-WAVES.

ACURIOUS and thoughtful letter in another column revives, with a different purpose, something very like Hartley's theory of the undulations in the whitey-brown matter of the brain, as the key to the phenomena of sensation. Hartley borrowed, or thought he borrowed, from Sir Isaac Newton the notion of a universal ether penetrating all space, and, of course, what we call vacua,— that is, spaces exhausted of atmospheric air,—through which undulations might be communicated between points physically separated, an ether also penetrating, though leas completely, the particles of solid bodies, and especially the nerve substance, lie held not only that sight, for instance, results from vibrations in such an

ether as this communicated to the optic nerve on the retina and thence propagated to the brain, but that all other impressions upon us are made in like manner ; that every impression so made is communicated to the whitey-brown substance of the brain, and thus constitutes or accompanies what we call "an idea," and that this vibration may be revived without the revival of the original sensory impression, and that when it is, we have the idea without the sensation. Hartley does not seem to have had any view of explaining by this hypothesis of his the sort of phenomena to which our correspondent "J. '1'. K." applies it ; but the theory is essentially the same, and hail Hartley lived the days of telegraphic communication, it is hardly likely that he would not have been glad to seize upon the telegraph as a new and tangible illustration of his theory, if he could have collected any considerable number of authentic facts such as "J. 1'. K." refers to, to which to apply it. "J. T. K." is inclined to accept what was in fact Hartley's theory of brain-waves, but uses it, not for the purpose of explaining as Ilartley did the phenomena of association of ideas and so forth, but for the purpose of explaining those few remarkable cases of mysterious sympathy between persons who have held no communication in words, which we may call thought-reading, by which it now and then occurs that one person, even though a stranger, deciphers the secret thought lurking in the mind of another, and, still more rarely, that persons who are not strangers, but who arc separated perhaps by the whole earth, become dimly sensible of events vitally affecting each other at the very moment they occur. The few cases on which "J. T. K." bases his hypotheses are remarkable enough, authenticated as they are by men known to the whole English public so well as Mr. Tennyson, Mr. Browning, and Mr. Woolner, men of remarkable intellectual shrewdness as well as genius, quite above the least suspicion of deception, and not at all likely to be easily taken in. But though quite willing to admit the facts, the hypothesis seems to us far from explanatory, and quite as much in need of independent evidence as the facts themselves, without, however, having any such evidence to adduce.

The theory is that every idea in any living man's mind is accompanied by a special physical undulation, which our correspondent calls a brain-wave—(the theory requires, by the way, that the same idea in A's and B's mind must be represented by totally different brain-waves bearing witness to their personal origin as well as to the contents of the idea itself), —that every brain-wave is transmitted in all directions into space, and that, if anywhere it comes upon' another brain under the very peculiar conditions—what the conditient; are being quite unknown—which make it sensitive to such a brain-wave, as paper chemically prepared is sensitive to the rays of light, then and there the brain-wave will be more or less clearly interpreted and translated into pictures or feelings so as to anticipate the channels of ordinary communication. Thus, in the case, authenticated by Mr. Wooluer, of the young man who, after years of uninterrupted silence between him and his friend, and while separated by the whole diameter of the earth, became aware of some terrible calamity affecting the latter, at the very moment when, allowing for the ditTeremice of longitude, lie was being tortured to death by the Maoris in New Zealand, "J. T. K.'s " theory requires that the brain-waves expressive of poignant suffering in this particular organization should have traversed either the solid body of the earth or its circumference in a time at least as short as an electric current, and should have become so far articulate in the brain of the young Englishman as to excite in his mind too, the impression of intense suffering in connection with this particular individual, and to prolong this impression so long as the suffering lasted. Now, what does the hypothesis contribute towards an explanation of the fact ? All that it contributes. is, that, if true, it would refer the fact to the well-known class of communications effected by transmitting motions along a continuous inedium,—that it reduces the case of the two friends separated by a globe eight thousand miles in diameter to the case of the Siamese twins, connected by a real communication between the nerves and blood-vessels of each. If there be such specific brain-waves corresponding to every individual idea in every individual organization, and if there be such an ether for transmitting these brain-waves, and if that ether transmits them with a velocity little less than that of electricity, or, at all events, light, then such a fact would be almost as intelligible as the power of one Siamese twin to divine any pang of intense suffering taking place in the other, without any help from either sight, touch, or hearing ;— we only say almost, because, if in any sense the Siamese twins had a continuous and unbroken nervous system, that would supply a machinery for telegraphic communication of which we do know something,—something more, at least, than we know of the supposed ether for transmitting brain-waves. But even in that case how little is explained, how nearly as inscrutable as ever the fact remains! Nobody, we believe, ever asserted that if you whispered very low into the ear of one of the Siamese twins, the other of them could hear what was said, or that if one of them only turned his eye on any new object, the other of them would see it. All that was ever asserted, as far as we remember, was that in this peculiar case there was an unusual amount of sympathy, tending to affect the health of either through the health of the other, just a heightening of that liability to contagion by which a cold runs through a family, or a fever is given by the wife to the husband. The simplification or generalization of facts,—which is what we meanby theory,—aud still more the discovery of 'cause,'— which is the ultimate object of science,—is not, as far as we can see, much facilitated, even if we could reduce this mysterious sympathy of organizations divided by a globe to the same general law as a like mysterious sympathy between organizations connected by a physical band of flesh, but not due to any of the known modes a communication by signs. We are just as far from understanding the process as before, and have got two or three purely hypothetical facts to investigate and account for, beyond what we had before.

Admit at once that some discharge of nervous force accompanies every act of mind, yet why should the discharge of nervous force be easier to imagine in connection with the other corresponding discharge of nervous force in the antipodes by which the friend here entered into sympathy with the tortured friend there, than would be the act of mind itself in direct connection with the act of mind? Suppose that whenever I think of the star Sirius a bell rings, or that whenever this bell rings, I think of the star Sirius, and that I do not know whether it is the bell ringing which precedes my thinking of the star, or my thinking of the star which precedes the ringing of the bell ; and suppose that whenever this happens another bell rings at the antipodes, and at the same moment a friend there thinks of the star Sirius. We maintain that, in the absence if any evidence whatever as to the sequence of these events, it is just as rational to assume that my thinking of the star Sirius leads directly to his thinking of the star Sirius, and that the ringing of the two bells is the -immediate consequence of the two thoughts, as it is to assume that the ringing of the bell here leads directly to the ringing of -the bell there, and that the ringing of the two bells leads to the two thoughts in question. We say there is absolutely nothing -whatever to choose in reason between the two hypotheses, and that if we know nothing of the sequence of the phenomena it will be impossible for any philosophic mind to prefer one theory to the other, or indeed to prefer either of them to a third,—that both events may be due to a common cause on each side of the globe. Now we have put this apparently eccentric supposition to explain why "J. T. K.'s" theory seems to us not properly a theory at all, but only a mode of asserting that it is easier to him to conceive of material links for intellectual phenomena, than of intellectual links for intellectual phenomena. Nay, his theory seems to us much less plausible than that of the man who should, in the case supposed, assert that the tinkling of my bell in some way causes, by the transmission of ethereal vibrations, the tinkling of his bell, and that the tinkling of his bell led him to think of the star Sirius,—less plausible for this reason, that "J. T. K.'s " assumed concurrence of physical phenomena is mere conjecture, so far at least as any human power to discern them goes, while the tinkling of a bell is at least an ascertainable fact. It seems to us that "J. T. K." explains the mysterious concurrence of sympathies, which is an attested fact, by physical phenomena which are to a certain extent purely conjectural, nolum per ignotam,— which is surely not very scientific. We say, to a certain extent, conjectural; for we admit that nervous force is doubtless expended in every act of thought, but it is surely pure conjecture to say that the quantity or quality of nervous force will vary specifically with the individual idea that passes through the mind ; that if I think of an eagle, for instance, the nervous force will be different in quantity or quality from what it would be if I thought of a lion or a whale. We do not say "J. T. K.'s" guess cannot be a true one ; but where is the advantage of it ? What simplification does it 'introduce? Here is a mind which, without any visible means of physical communication, falls into sympathy with another mind at a vast distance. The theory says, 'well, as there is no visible means of physical communication, let us assume an invisible means which we cannot verify.' Why ? What do we gain by it but a new complexity without any evidence? Even if the specific brain-wave

were proved, unlessjIve could prove,that the:brain-wave entered the brain of the Londoner some infinitely:small time before his sympathetic mental suffering began, we should have no more reason to believe that the brain, wave caused the suffering than we should have to believe that the suffering caused ;the brain-wave. But in the absence of the evidence for any suchltransmitted brain-wave at all, we submit that the theory complicates instead of simplifying the facts.

Surely it is quite evident that our correspondent's hypothesis is not only premature,—as we have for too few authentic facts on this curious subject to admit of generalization at all,—but really a new difficulty which, so far from explaining, only complicates the remarkable phenomena it attempts to explain. We hold, however, with him that there is very good reason to look for much new light on the laws of mind from a careful collection of really well-authenticated and accurately recorded facts of this nature,—(narratives of the sort either inadequately authenticated or inaccurately recorded are of no use in the world, and have already probably retarded any chance of theoretic generalization by their unfortunate exaggeration, vagueness, and abundance),—and that the facts he has produced are authenticated in a manner and recorded with an explicitness which make them admirable specimens of what is wanted.

Dr. Carpenter, in the remarkable paper read at the Royal Institution last March, on "the Unconscious Activity of the Brain," to which we referred in the article on "Disconnected Memories " last week, states that he has some evidence tending to prove that thought-reading, such as "J. T. K." tells us of, will occasionally take place, where the thought read is not the thought then present to the mind of the person whose thought is read,—but a former and sometimes quite inconsistent thought, which he had once entertained, but which he has utterly forgotten and entertains no longer. His words are, "Cases have occasionally occurred in the experiences of persons above suspicion of intentional deception, in which the answers given by the movements of the tables were not only unknown to the questioners, but were even contrary to their belief at the time, and yet afterwards proved to be true. Such cases afford typical examples of the doctrine of unconscious cerebration ;' for in several of them it was capable of being distinctly shown that the answers, although contrary to the belief of the questions at the time, were true to facts of which they had been formerly cognizant ; but which had vanished from their recollection,—the residua of their forgotten impressions giving rise to cerebral changes which prompted the responses, without any consciousness, on the part of the agents, of the latent springs of their actions." One would like to have some adequately authenticated cases of this nature. If there be such, it would be curious to see whether "J. T. K." could reconcile them with his theory of brain-waves. He would have to maintain that the undulations of past " brain-waves " originating in facts, were so much intrinsically stronger than the new brain-waves due to the (mistaken) opinion of the moment, that they took precedence in the organization of a third person, although they had not had power to overpower the newer and feebler brain-waves in the very brain from which they flowed. Surely this would be a slightly complex hypothesis. The old "brain waves" which have ceased to overflow the mind in which they sprang, and have been extinguished by others, yet reassert their power, to the exclusion of these last, over a third organization,—as if, for instance, in the story told by Mr. Browning of the shirt-studs, he had himself, at the time, held a wrong impression as to the fate of the person to whom they had belonged, but having once held a right impression which he had forgotten, that obliterated right impression had had power to originate a " brain-wave " wholly overpowering in the mind of the sensitive Italian Count the" brain-wave" caused by his immediate error. There are two queer and very improbable anonymous stories in the new (February) number of the St. Penis magazine, in an article called "Life Studies," wherein an old chair and old sofa are asserted to have so stored up relics of the pain endured by former occupants of them, as to impress the organizations of complete strangers resting upon them, strangers who had never heard of their former occupants. Anonymous stories are worth absolutely nothing, but if such a class of cases should ever be authenticated at all, the " brain-wave " theory would hardly apply to them, and "J. T. K.'s" Italian Count might have received his impression not from Mr. Browning's mind, but from some to us utterly invisible traces of the past lingering about the gold studs themselves.