SCIENCE FROM AN EASY CHAIR.

Press, Volume L, Issue 14987, 6 June 1914, Page 9

SCIENCE FROM AN EASY CHAIR.

THAT W T HICH MIGHT BE AND THAT WHICH IS.

(By Sir Rat Lankester, X.C.8., F.R.S.) -, . ■ ■

(Special rights secured by "The Press.")

If you walk into a telegraph operator's room you will, see (or would havo done so a few years ago) darjrlike steel ."needles" each supported on an upright board by a centrally-placed pivot and swinging with a jerking, irregular moVomont, hitting a,"stop," first one on the left and then one on the right, making a sound which may be represented by "tat—tat tat-^-tat— tatty tat' —tat tat"—and so. .on indefinitely. These needles are making movements, to the left and to the right, separated' by long and short-, intervals —which are read by the operator in accordance Iwith a code co that they signify the various letters of the alphabet. He does not require to see the movements; the successive taps of sound aro enough for him, and he spells out a message.of "words," the letters of which have been given by the grouping of long and short taps and intervals. The move-. j ment of the neodlo is caused by an ' electric current-' brought by a wire I which joins a coil behind tho moveable needle. The needle is specially [ magnetised, and moves so as to place I itself at right angles to the electric ! current whenever that current passes. The operator at the other end of the wire, somo hundred or more miles away, is sending t'he electric current through the •"ire at intervals corresponding to the taps. He knows the "code" by which such and such taps and intervals correspond to such and such letters of the alphabet, and so he spells out words by intermittent currents at one end of the wire, and the i receiving operator at this end takes them down. .

They have a code by which taps at proper intervals indicate letters of the alphabet. Further, they have a second code which all persons who can road the English language make use of, namely, that by which letters eombiued into certain groups are interpreted as equivalent to certain sounds which wo call English " words." Further, they are making use of yet a third "code," or pre-arranged understanding—the common convention of human speech—by which these word-sounds convey definite meaning!. So the one operator can convey information and most of what he could convey by audible speoeh to tho other operator. But observe! Ho is using a peculiar and clever "receiving apparatus," by which tho needle is made to move intermittently, and is also using, three purely arbitrary pre-arranged codes or agreed systemsby which (1) certain taps shall mean certain letters, (2) combinations of letters shall mean certain sounds or spoken words, and (3) spoken words shall mean thoughts. Ho is using nil this in addition to tho electric current.

tt is not difficult to mako a telegraph needle movo by means of an electric disturbance which is not brought to it by a wire. In tho absence of a connecting wire a telegraph needle resting over a . coil. may be made to movt- intermittently by atmospheric electric at a distance of some feet from it. P'veryono knows the distant action of a magnet, and that a gold-leaf electroscope is set • in movement by an "electrified" glass rod brought to a point at some distance from it, and that pith balls will jump to tho glass" rod without its coming within five or six inches op them. "Action at a distance." as it is called, is a familiar and everyday occurrence. We do not require to be in contact with a furnace in order to be acted upon by the heat-waves which radiate from. it. It. acts at a distance—radiating heatwaves. Hence, it is not surprising that wireless telegraphy over short distances should be possible. Electric waves are generated by "a "special machine, and they travel until they reach, a receiving apparatus with a tell-tale needle or sounding apparatus. Then if the electric waves are intermittent the movement of the needle is intermittent and

the code of interpretation can be applied. ,

The thing which has proved astonishing and of vast practical importance is that by means of very powerful machines generating peculiar and tarreaching electric waves and by the use of specially delicate receiving apparatus, movements can be set going in a receiving apparatus separated from a generating machine by an immense distance, namely, a thousand miles and more, over land and sea. An essential feature in the success of this longdistance wireless telegraphy has been the invention of new apparatus sufficiently delicate to detect with certainty the electric waves \v%,en they arrive— having travelled with the rapidity of light—across these vast distances. One "detective" apparatus deoends on the fact that such waves affect the state or contact of the granules of a powder made of fine filings of the metals silver and nickel, in such* a way as to reduce the resistance which tho powder offers to the passage of a feeble voltaio current (one-cell). "The long.distance waves cause a slight "setting of the metallic particles, so that, whilst that is acting, tho feoblo voltaic current can pass (from one bit of wire to another separated only by a little of the metallic powder). But when the longdistance waves stop, the metallic particles cease to "cohere" (as tho inventor phrased it), and tho weak current does not pass. The apparatus was hence called a "coherer." The passage of the weak voltaic current through the coherer is made evident to the tehv graph operator by causing the current to act on a telephono apparatus. When the voltaic current "passes" a slight continuous hissing sound is heard by tho operator, who holds tho telephone disc to his ear. But when the discharge of long-distance waves a thousand miles off ceases tho hissing sound 'in the telephono also instantly ceases. Accordingly the operator who is discharging long-distance electric-waves a thousand miles off can time them so as to produce sounds following ono another in group- :>b intervals, and can discharge them in long and shor* trains (they sound liko this, viz., hees —bees —his-his —heos*—his-be«o, so as to represent by sound tho dash and dot ' signals of the Morse alphabet Using the Morse code the discharging operator sends his message, spelling it out alphabetically, just as the ordinary wire- ! i:sing telegraohist does. And by tho knowledge'of* t-hfit M<rse code the receiving operator is able to translate tbe "bees—hees-his" of the wireless moss-.T-p into letters of the alphabet and words and so receives '^information."

Thero are s%»*eral other kinds of detectors or ware-receivers in use beside "coherers." One which I havo seen in operation depends on the fact that tho gaseous film which forms on two surfaces of platinum placed in nitric acid when "a weak voltaic current passe? from one surf nee to tho other, causo

-stance to the passage of the current and, in fact, arrests it. But tho longdistance waves arriving disperse the film and annul the resistance. Accordingly this aparatus can be used in the same way as the "coherer" to produce alternate sound and silence in a telephone apparatus by the making and breaking of a voltaic current, determined by the distant operator discharging the "great Hertzian waves into the atmosphere

I havo endeavoured in Ehe foregoing paragraphs to put the simple facts about wireful and wireless telegraphy plainly, because when Marconi first introduced his system of wireless telegraphy some strangely ill-informed people wero allowed to write in tho newspaper Press with the purpose of" «innouncing to the wonderswallowing members of the public that this new marvel rendered it impossible to deny any longer that even moro marvellous communication of mind with mind which had lately been dubbed "telepathy." Just in the same way, it was said, as the electric waves; pass from one Marconi station to anther without wire or conduit, so do brain waves pass from one "brain over thousands of miles to another! Even tho friend of Tyndall and of Huxley, the amiable Mr James Knowles, made on this subject one of the rare communications written by himself —if not, indeed, tho only! one —punished 1 in the "Nineteenth Century," founded and edited-by him. This brief article was intended to set forth what he considered to be the greatly increased probability of the truth of the suppositions of those who believe in the transmission of information from brain to brain by brain waves, now that Marconi was daily transmitting such information by electric waves. ; Ho and others who reasoned in the same way omitted to give any attention to the fact that all that wireless telegraphy does actually produce at a distance from the operator is a series of very delicate electric disturbances, and that these would not be noticeable at all by a human being unless he had availed himself of a detector (coherer or other), and converted the slight olectric disturbance into a sound or minute movement of mass. We do not know of 'the existence of "brain waves," nor do the persons who talk of them tell us in what material these waves are supposed to occur. But if wo let it be assumed that these hypothetical brain-waves exist, how ate we to suppose they are "received" by a second brain ? We do not know of any apparatus in connexion with tho human brain which can reasonably be supposed to act as a "detector" and convert these supposed-brain-waves into a sensible form, as is necessary in the operation of wireless telegraphy. Moreover, supposing we admit "X'at there is some undiscovered detector apparatus, like the Marconi adherer, acting so as to receive the undiscovered but assumed brain-waves discharged Intermittently by a distant brain, what agreement has been made botween the owner of one brain and the owner of another corresponding to the Morso alphabet? Without somo such code the brain-waves could convey no information: and yet none of those who think they have received "telepathic" communications profess to have any knowledge of a code or to bo able to interpret intermittent signalling by brain-waves. It is worth while taking note of this, because a great number or semi-intelli-gent people who are moved to wonder and a pleasurable sense of mystery by tho imperfect reports of scientific and medical discoveries now frequent in tho daily Press were led by the supposition that "telepathy" was analogous to "wireless telegraphy" into a firm belief in the existence of the former, and there they have remained ever since, with a comfortable assurance that theii belief has somehow or another a eort of a scientific basis.

It is however, very desirable to induce our fellow-citizens to think, methodically, to give duo_ value to evidence of'fact and to distinguish it from fanop opinion, and hope. In fact, to distinguish "that which is. ' and can ho shown to "be," from that which "might be" or "may be," and can be fondly imagined and eloquently talked about, but is never demonstrated, produced, or shown to be. It appears now that though some of the believers m "telepathy" have entertained the notion that the sense-organs and the suostane'e of the brain aro acted on by imaginary brain-waves emanating ""P 1 distant brains, vet that the late Mr J. Mvers and other leading believers in "telepathy" disavow altogether any explanation* of "telepathy" as arising from the action of waves or impulses (similar to those of known physical forces) upon the sense-organs or physical structures of the recipient. The orthodox view appears to be now that there is a something called "spirit, independent of matter. and its associated modes of motion, and that telepathy" is due to the communication of spirits with snirits in their own unknown and possibly unknowable ways. There does not seem to be much for

a» reasonable man to say when such assumptions are made, excepting that they are assumptions, and altogether unwarranted assumptions. The real point to which attention should he directed is this: "Are the statements as to fact, which are said to ne«.v_si- j "tate tho supposition that one human mind can communicate with another without making u*o of the ordinary channels ot tho souses sufficiently wellsupported to warrant their acceptance "r" They v.re of two distinct groups. A. records of experiments on persons in which the aim was to transfer selected images, etc v from an initiating to a receiving mind by mere thought and without any appeal to the sense-organs. The reality of the transfer is estimated by comparii.g- the number of identities obtained in the thought of the initiator and the guess of the receiver with those which would he obtained by mere coincidence in a long series of trials. It is a curious and significant fact that in a long series of experiments in this thought-traasfnr-ence it was found that when the persons acting as initiator and receiver respectively were in separate rooms tho guess of the receiver as to what had been thought of (usually a number or a shape) by the initiator was not more frequently correct than was to he expected by unbiased coincidence. But when the receiver and the initiator were in the same room (and therefore capable of communicating through the so uses whether consciously or unconsciously) nine--y successes woro recorded in 017 trial* whereas if due to unbjased coincidence there should have been only eight.' "In no series of any length."' says Mr N W. Thomas ("Encyclopaedia Britannica," article "Telepathy"), "wero tho successes so far above chance as to five substantial support to a belief in telepathy." Nevertheless, another writer, Professor McDougall, of Oxford, ex-plicitly-states (article, "Hallucination," "Encyclopaedia Britannica," that it is because "good evidence of telepathic communication has been obtained" that tho least improbable explanation of death apparitions i s that the dying person exerts upon his distant friend "some telepathic influence which generates an hallucinatory perception of himself. ' This is terribly misleading. For thero is not (so Mr Thomas assures us) good evidence of telepathic communication oven from a person so near to another as is implied in the initiator and recipient being in adjacent rooms!

Tho stories of apparitions of. distant persons to their friends, either at somo very critical moment or (in by far the largest number of cases) at or soon after death, at-e credible in so far as they record the occurrence now and then of such liallucinations. The chance that such an hallucination will occur to A.'s friend or relative within twentyfour hours of A.'s death is one in 19,000 (tho death-rate being just overly i/i tho 1000 ncr annum), whilst it is OJ-365th of that, or l-19th in tho 10C0 for a single day of twenty-four hours). A collection was mado by a committee, over which Professor Henry Sidgwick presided, of 1300 cases of such apparitions related by the persons who had experienced them. Thirty of these cases were death coincidences —that is to say, the person who "appeared" died within twenty-four hours. This rate is not one, but 440, in 19,000, so that the committee inferred that some undetected agency was at work causing this increase of coincidence of the apparition and death from one in 19,000 to one in 43. That is a true and just statement of tho case.

" But I do not agree with Professor McDougall that "telepathy," not otherwise known to exist, 6hould be hero invoked, unknown and untested as it is, in order to generate "hallucinatory perceptions," nor need wo jump to the conclusions iv favour rf altogether unproven spiritual emanations and influences favoured .by other critics of the committee's report. To mc by far the most probable explanation of the increase in coincidence of death and hallucination, iii the recorded cases as compared with what one would expect from the death-rate, is not to be sought in any occult force or ghostly possibilities, but in a well-estab-lished and recognised, though regrettable, reality which I will call "uuman frailty." This intellectual frailty consists "in the inaccuracy—sometimes unintentional, but often deliberate—of narrators of snch stories, tho inaccuracy which arises from incorrect observation both of the apparition and its date as well as incorrect record of the death of the appearing individual, inaccuracy as to record (and consequent oversight) of autecedent circumstances which made it likely that tho person whose hallucinatory apparition was seen should be specially thought of or should ho specially likely to die, or both, on or about the date on which the apparition was seen. But it is not only in the narrator that this human frailty is active. It also leads the collectors and examiners- of these stories to accept statements in favour of their own prepossessions, and prevents them from doubting the -veracity and intelligence of f.heir favourite witnesses. A last and most appalling form of "inaccuracy" consists in the transference by a narrator to himself of an experience which he has never had, but only heard of. In cases where the narrative has passed from tho original observer To a second or a third reporter, it is my opinion that, in regard to such a "matter of fear and wonder," no value- at- all can h« attached to +he story.- and no statistical use should be made of it.