THE FALLACY OF THE PRESENT THEORYofSOUND MOTT. THE FALLACY OF THE PRESENT THEORY OF SOUND BY HENRY A. MOTT, Jr., Ph.D., E. M., etc. v« ' PROFESSOR OF CHEMISTRY AND PHYSICS IN THE NEW YORK MEDICAL COLLEGE AND HOSPITAL FOR WOMEN AUTHOR OF Ttie Chemist's Manual“ Was Man Created “ Adulteration of Milk", Testing the Value of Rifles by Firing under Water”; “The Laws of Nature “ The Air We Breathe, and Ventilationsetc. NEW YORK PRINTED FOR THE AUTHOR BY JOHN WILEY & SONS 15 Astor Place 1885 Copyright, 1885, By HENRY A. MOTT, Jr. M. H. GREEN, 74 and 76 Beekman Street, NEWYORK. PREFACE. To attack a theory which has been upheld for 2500 years, and which has been and is sustained by the greatest living scientists, is certainly a very bold undertaking. The nature of the undertaking should not, however, deter truth from asserting itself, or deter any scientific man, with sufficient individuality and independence, from exposing the fallacy of the same, if such fallacy can be shown to exist. The author therefore makes no apology for thus coming to the front and joining Dr. A. Wilford Hall in exposing the fallacy of the present theory of sound, for he believes that it is the duty of every man to do his own thinking and not allow others to think for him. The old saying, ‘ ‘ The name is but the shadow, which we find Too often larger than the man behind,” is too true to be overlooked. Great names often carry with them too much authority, and it requires a well-balanced mind to properly attach the correct importance which in PREFACE. IV many cases such names deservedly merit. To accept, therefore, the present theory of sound as correct because it is sustained by “great names,” and because on the authority of such names it is pronounced correct, without exercising any individuality of thought to inquire into its merits or demerits, would be only to impede the progress in search of truth, and not only impair the value of scientific deductions, but at the same time limit the pro- gress of science. That the reader may feel satisfied that other scientific men besides those mentioned in the following pages have arrived at the same conclusions as the author, he deems it advisable to introduce here the opinions of some well-known scientists on Dr, Hall’s discovery. Opinion of Dr. H. H. Adams, President of Wesleyan University. “ I have examined the new theory of sound—or rather, as it seems to me, the complete overthrow of the undulatory theory. Other members of the faculty have come to the same conclusion as myself.” Opinion op Prof. J. L. Kephart, A.M., of San Joaquin College, Cal. (formerly of Western College, Iowa). “ I have no hesitation in admitting that, in my opinion, the undulatory theory of sound is hopelessly shattered.” PREFACE. V Opinion of Peof. Osboen, LL.D., of Madison Univeesity. “The part on sound I prize very highly—a new departure that must be permanent and lead to many modifications of old notions.” Opinion of Heney 0. Cox, A.M., Peofessoe of Physi- cal Sciences, Pickaed Institute, Chicago. “ The first division of the hook is given to a discussion of the wave-theory of sound; and so completely does he show the absurdity of that hypothesis that we feel mortified to reflect that for fifteen years we taught it as science,” Prof. Thomas Munnell, A.M., former President of Hiram College, Ohio, no longer believes in the current theory of sound, and thinks it will not be long before the scientific leaders of this century will abandon it also. Prof. J. W. Spangler, President of the American College, Concepcion, Chili, S. A., states that “ the wave- theory of sound has been demonstrated [by Dr. Hall] to be a pure fallacy.” Prof. Jacob Chapman, A.M., of Exeter, H. H., formerly Professor of Mathematics in Dartmouth College, and who held the same position for years in the Franklin PREFACE. and Marshall College, and who believed in and tanght the wave-theory of sound, has declared that he has abandoned that theory as entirely wrong, Charles H. Goddaed, 8.A., LL.B., Professor of Physical Sciences and Biology in Nebraska College, at Nebraska City, has abandoned the wave-theory of sound as false. Peof. J. W. Lowbee, M.A., Ph.D,, former President of Columbia College, Ky., writes that he has totally abandoned the wave or undulatory theory of sound. Peof. C. H. Kieacofe, A.M., President of Hartsville (Indiana) University, states: “We no longer teach the wave-theory of sound as science, but as a theory worthy of consideration only as an example of what may be palmed off on the world as true science.” It must be agreed that the opinions here presented against the wave-theory of sound cannot be ignored as unworthy of notice by the eminent scientific men as- sailed ; for such an array of careful thinkers as above {and numerous others could be mentioned) who have without reservation denounced the wave-theory of sound as fallacious must certainly be entitled to respect and consideration. If Prof. Helmholtz, Tyndall, Lord Raleigh, Sir William Thomson, in Europe, and Prof. Rood and Mayer, in this country, wish to retain the respect and PREFACE. confidence of thinking people, they will at once endeavor either to defend the theory of sound, or like men come boldly to the front and acknowledge that it is fallacious. I cannot conceive of an educated scientist, especially one who respects his name and values the opinion others may hold of his ability, integrity, and honor, who could under the present state of facts remain silent; especially if he has been a teacher of the theory which is now not only questioned but denounced as false by prominent scientific professors in our colleges and universities. Their silence, if such should prove to be the case, could only be attributed to defeat and cowardice. For no matter how well educated they may be, it must be acknowledged that other men are educated also, and that such men command the respect and confidence of think- ing people; their opinions are of value, however, only in proportion as their deductions are logical and consistent with facts; so that if they should err in denouncing the current theory of sound,—and if this was demonstrated by an acknowledged supporter of the theory,—such a man who should expose their false deductions would cer- tainly be respected, while a man who is unwilling to de- fend his assertions is not entitled either to respect or con- sideration. Author. PREFACE. N'OTE. The author would be greatly indebted to any reader of this book if he would kindly forward to him any pub- lished review or criticism of the same, whether in favor of or against it. Such courtesy will be promptly acknowledged. Author. 61 Broadway, New York City, N. Y., U. S. A. LEOTUEE ON THE FALLACY OF THE PRESENT THEORY OF SOUND.* Ladies and Gentlemen : “The object of science is not to find out what we like or what we dislike ; the. object of science is truth.” Galileo has stated that the truth or falsity of an hypo- thesis must be judged by the weight of the facts and the force of mathematical deductions, and not by super- ficial appearances or the plea of authority based about what philosophers may have taught. This line of reason- ing clearly applies to the present theory of sound which I have the pleasure of directing your attention to this evening. Simply because the wave-theory of sound was * Lecture delivered before the New York Academy of Sciences, December 8, 1884. Held at Columbia College. 6 THE FALLACY OF THE PRESENT THEORY OF SOUND. inaugurated by Pythagoras 2500 years ago, and has been sustained by Newton, Laplace, Helmholtz, Tyndall, Mayer, Rood, Blaserna, and a score of other distinguished scientists, is no reason why such theory should not be judged by “ the weight of facts and the force of mathe- matical deductions.” Too many theories which have had the indorsement of scientists have been exploded to permit of the accept- ance of anything in science on trust, or believing any- thing to be positively correct and true just because it is sanctioned by the indorsement of a long and immortal line of scientific names, especially if the subject has not received the most scrutinizing scientific examination from every possible standpoint. Theories in science are of great value to deduce explar nations for various unsolved problems; and when the correct theory is discovered which will explain and con- form with any particular problem under consideration in all its details, as known, then the theory ceases to be a theory and becomes a law. The assumption, however, of necessity must always exist, if the law be accepted as correct that we are either acquainted with all the details respecting the problem under consideration, or that if any new facts or details should afterwards turn up they would conform to the law. If they do not so conform, then the so-called law reverts back to the nature of a THE FALLACY OF THE PRESENT THEORY OF SOUND. 7 theory requiring either modification or complete anni- hilation. It is to the complete annihilation of the undu- latory theory of sound that your attention is directed. In 1877 Dr. A. Wilford Hall published a work on the Evolution of Sound, in which he carefully considered step by step the present undulatory theory of sound as elucidated by the distinguished authorities already referred to. It is needless for me to say that he has, not only in my opinion, hut also in the opinion of numerous scientific men, shown the fallacy of the present theory of sound, otherwise I would not he here this evening to present before a scientific body, in a lecture, the sum and substance of the numerous fallacies pointed out by him and other scientists besides myself who have carefully investigated the subject. To proceed properly it will be best for us to review with some care the present theory which has been so very generally accepted as correct, and which is at this moment being taught by all the schools and leading universities of the world, with the main object of cor- rectly enlightening students and searchers of truth as to how we hear or appreciate sound. But before I proceed I must respectfully ask your most critical and analytical attention to the present theory of sound, which I shall endeavor to conscientiously lay before you as it is expounded by such men as Tyndall, Helmholtz, Lord 8 THE FALLACY OF THE PRESENT THEORY OF SOUND. Rayleigh, Mayer, Rood, Sir William Thomson, Blaserna, and other distinguished scientists and recognized authori- ties on acoustics, with the belief that you will see in the theory, independent of facts I shall give later on, suffi- cient impossibilities and contradictions to cause you to wonder why such a theory could be entertained at all. Professor Rood has defined sound as a sensation pro- duced when vibrations of a certain character are excited in the auditory apparatus of the ear, and states that these vibrations are generated by progressive tremors in the atmosphere, called sound-waves.* This definition, while setting forth briefly the present theory of sound, will not be sufficiently elaborate for us to-night, so I will there- fore enter into much fuller explanation, based, as I have already stated, upon the propounded facts of the various authorities on this subject. These authorities state that when a body capable of emitting a (musical) sound—a tuning-fork, for example —vibrates, it moulds the surrounding air into sonorous waves, each of which consists of a condensation and a rarefaction, and in the condensed portion the air is above, and in the rarefied portion is below, the average tem- perature, and this change of temperature produced by the passage of the sonorous wave itself virtually augments * Johnson’s Cyc.; Acoustics (0. N. Rood). THE FALLACY OF THE PRESENT THEORY OF SOUND. 9 the elasticity of the air and makes the velocity of sound about one sixth greater than it would be if there were no change of temperature.* But the average temperature of the air is unchanged by the waves of sound, as we can- not have a condensed pulse without having a rarefied one associated with it, and the temperature of the rarefaction is as much lowered as it is raised in the condensation; f so that from a vibrating body, such as the tuning-fork referred to at the end of a second from the time it com- menced its vibrations, the foremost wave would have reached a distance of 1095 feet in the air at 0° C. or 1120 feet at 15° C. The prong of the vibrating fork in its swift advancement compresses the air immediately in front of it, causing the particles of air to crowd together, and when it retreats it leaves a partial vacuum behind it as the air-particles separate more widely,% the function of the fork being to carve the air into these condensa- tions and rarefactions,§ and they, as they are formed, propagate themselves in succession through the air. If a ball is urged against a number of balls placed in a groove, the motion thus imparted to the first ball is delivered up to the second; the motion of the second is delivered up to the third; the motion of the third is * Tyndall, Lectures on Sound (Ist ed.), pp. 29, 45, 46. t Tyndall, loc. cit. p. 39. § Tyndall, loc. cit. p. 63. X Tyndall, loc. cit. p, 28. 10 THE FALLACY OF THE PRESENT THEORY OF SOUND. imparted to the fourth: each ball after having given up its motion returning itself to rest, the last ball only of the four flies away. Thus is sound conveyed from parti- cle to particle through the air; the particles filling the cavity of the ear being finally driven against the tym- panic membrane, which is stretched across the passage leading to the brain, setting this membrane which closes the drum of the ear into vibration,* so that it bends once in and once out by each pulse.f In this transferrence of the vibrations of the air into the laby- rinth, it is to be observed that though the particles of the air themselves have a comparatively large amplitude of vibration, yet their density is so small that they have no great moment of inertia, and consequently when their motion is impeded by the drum-skin of the ear they are not capable of presenting much resistance to such an impediment or of exerting any sensible pressure against it 4 But still Professor Tyndall says that if we hear one sound louder than another, it is because the ear is hit harder in the one case than in the other by the vibrating air-particle. § At this point it appears proper to describe briefly the * Tyndall, loc. cit. pp. 4, 5. X Sensations of Tone (Helmholtz), p. 199. § Tyndall, loc. cit. p. 11. f Tyndall, loc. cit. pp. 49-60. THE FALLACY OF THE PRESENT THEORY OF SOUND. 11 formation of tlie ear as relates to the membrana tympani. This membrane separates the cavity of the tympanum from the bottom of the external meatus. It is a thin semi-transparent membrane, nearly oval in form, some- what broader above than below, and directed very obliquely downwards and inwards. Its circumference is contained in a groove at the inner end of the meatus, which skirts the circumference of this part except above. The handle of the malleus descends vertically between the inner and middle layers of this membrane, as far down as its centre, where it is firmly attached, drawing the membrane inwards, so that its outer surface is con- cave, its inner convex. “This membrane is composed of three layers, an external (cuticular), a middle (fibrous), and an internal (mucous.)” “ The fibrous layer consists of fibrous and elastic tis- sues. Some of the fibres radiate from near the centre to the circumference; others are arranged in the form of a dense circular ring round the attached margin of the membrane,” The tensor tympani draws the membrana tympani inwards, and thus heightens its tension. “ The laxator tympani draws the malleus outwards, and thus the membrana tympani, especially at its fore- part, is relaxed.” The stapedius muscle by inclining 12 THE FALLACY OF THE PRESENT THEORY OF SOUND. the stapes backwards is supposed to compress the fluid contents of the vestibule. The tympanum is traversed by a chain of movable bones which connect the membrana tympani with the labyrinth, and serve to convey the vibrations communi- cated to the membrana tympani across the tympanum to the internal ear. The outer wall is formed by the mem- brana tympani, a small portion of bone being seen above and below this membrane. It presents three small aper- tures: the inter-chordse posterius, the Glaserian fissure, and the inter-chordae anterius. Through the first the chorda tympani nerve enters the tympanum; the aper- ture of the inter-chordae anterius being above the Glase- rian fissure, and through it the chorda tympani nerve leaves the tympanum.* It might here be stated that the membrana tympani is claimed to be capable of responding to an immense variety of waves or impulses. “A catholicity of the kind,” says Prof. Rood very truthfully, “ has not thus far been observed in experiments on membranes artificially stretched, whose range is found to be far more limited.”f The vibrations produced within the membrana tym- pani by the waves of sound are transmitted to the mem- * See Gray’s Anatomy, pp. 697-699. f Johnson’s Cyc.: Acoustics (Rood). THE FALLACY OF THE PRESENT THEORY OF SOUND. 13 branous covering of the fenestra ovalis by means of tbe cliain of bones within the cavity of the tympanum, and through secondary vibrations produced within this mem- brane the impulse is transmitted to the fluid of the vestibule. According to some authorities, the jarring of the otoliths against the filaments of the vestibular nerve affords, at this latter point, a perception of the intensity of the sound which is being appreciated by the ear.* The vibrations now travel along the fluids of the scala vestibuli of the cochlea and of the semicircular canals, thus passing in two different directions. The little sacs f contain, attached to their walls, small crystals of carbonate of lime in contact with the nerves ; and their function, as it appears, is to render us sensible of simple short sounds or shocks which probably would not affect the rest of the vibratory apparatus. They act as drags on the nerves when the latter vibrate with the Water in which they are bathed and thus produce sensa- tion. These sacs contain also, in connection with the nerves, certain microscopic hairs that are quite elastic and brittle, and probably capable of being set into vibration when the particular notes to which they are tuned are presented to them, just exactly as a tuning-fork can be * Darling and Ranney, Essentials of Anatomy, p. 596. f Rood, loc. cit. 14 THE FALLACY OF THE PRESENT THEORY OF SOUND. set in vibration by the waves proceeding from a second fork of the same pitch. In the semicircular, canals, according to some observers, the direction from which the sound springs is perceived, while the vibrations carried along the scala vestibuli are transmitted to the filaments of the auditory nerve in the organ of Corti and those connected with the membrana basilaris, thus affording the perception of the note and the quality of the sound perceived. After reaching the apex of the cochlea the vibrations are transmitted from the scala vestibuli downwards along the tympani secundaria, which covers tho, fenestra rotunda, where the vibrations are lost; being no longer transmitted, on account of the absence of any conducting medium. The free entrance of air to the cavity of the tympanum, or the middle ear, affords an equal density of air upon either side of the membrana tympani, and thus insures a vibration of that membrane in absolute unison with the vibrations of the sound which it is called upon to record.* The function of the organ of Corti in the cochlea is described as follows : When the vibrations reach the end of the auditory nerve, some of the numerous rods or fibres of the Corti arches which bristle around the ap- pendages of this nerve will be strongly excited by such * Darling and Ranney, loc. cit. p. 596. THE EALLACY OE THE PRESENT THEORY OE SOUND. 15 vibrations as are in unison with them, and some will not; so that simple tones of different pitch will excite different fibres, showing that this wonderful organ discovered by Marchese Corti is a musical instrument, with its cords so stretched as to accept the vibrations of different periods and transmit them to the nerve-filaments which traverse the organ.* If the sound is a compound, or the form of the wave abnormal, this sound is, according to Helmholtz, analyzed into its constituents, since the cords (and rods) can only execute normal vibrations; and we see finally that the clang tint is the sensation produced by the simultaneous action of two or more of these strings upon their appro- priate nerve. The cochlea contains about 3000 of these strings, and if with Helmholtz we suppose that 200 of them are useful for rendering us sensible of tones not used in music, there will remain for the musical tones proper 2800 for the seven octaves, or 400 for each octave, 33|- for each half-tone.f The final vibrations are sent along the auditory nerve to the brain, where they are translated into sound. The abnormal sounds perceived when the Eustachian tube is obstructed by swelling of the mucous lining during attacks of severe influenza are due, in great * Tyndall, loc. cit. p. 324. f Rood, loc. cit. 16 THE FALLACY OF THE PRESENT THEORY OF SOUND. measure, to the impaired entrance and exit of air. It is customary for gunners when firing large cannon to stand with the mouth open, since by so doing the vibrations of the air produced by the explosion are transmitted through the Eustachian tube as well as through the auditory canal, and by neutralizing each other the drum membrane stands almost motionless, and little, if any, sound is perceived.* The motion of the sonorous wave, says Tyndall, must not be confounded with the motion of the particles which at any moment form the wave; for during its passage every particle concerned in its transmission makes only a small excursion to and fro, the length of the excursion being the amplitude of the vibration f on which the loudness or intensity of a note depends, as well as it de- pends on the difference of density between the condensa- tions and rarefactions. So that, if two forks were made to vibrate so that the condensations of the one will coincide with the condensations of the other, and the rarefactions of the one with the rarefactions of the other, thus sup- porting each other, a sound of greater intensity will be produced than that of either vibrating alone.;]: It is evident, however, that at each point in the mass of air at * Darling and Ranney, loc. cit. p. 596. \ Tyndall, loc. cit. p. 44. % Ty % Tyndall, loc. cit. p. 358. THE FALLACY OF THE PRESENT THEORY OF SOUND. 17 each instant of time there can be only one single degree of condensation, and that the particles of air can be mov- ing with only one determinate kind of motion, having only one single determinate amount of velocity, and passing in only one single determinate direction.* So that two different degrees of density produced by two differ- ent systems of waves cannot coexist in the same place at the same time; although the air is competent to accept and transmit the vibrations of a thousand instruments at the same time,f each particular sound passing through the air as if it alone were present $ the pitch of each note depending on the number of aerial waves which strike the air in a second. Tyndall states that when the tympanic membrane is shaken by the shock of a series of pulses at regular inter- vals, it cannot come instantly to rest.§ And Helmholtz states that an elastic body set into sympathetic vibration by any tone [whether in unison or not] vibrates sympa- thetically in the pitch or with the vibrational number of the exciting tone; but as soon as the exciting tone ceases, goes on sounding in the pitch or vibrational num- ber of its own proper tone.]] This in the face of the fact stated by him that membranes tuned to be in unison with * Helmholtz, loc. cit. p. 40. X Tyndall, loc. cit. p. 281. 11 Helmholtz, loc. cit. p. 215. f Tyndall, loc. cit. p. 287. § Tyndall, loc. cit. pp. 49, 69. 18 THE FALLACY OF THE PRESENT THEORY OF SOUND. the combinational tones are set in sympathetic vibration immediately upon both generating tones being sounded simultaneously, but remain at rest if only one or other of them is sounded.* To close the consideration of this side of the undula- tory theory, I will add that Tyndall states that when we try to visualize the motions of the air having one thou- sand separate tones,—to present to the eye of the mind the battling of the pulses, direct and reverberated,—the imagination retires baffled at the attempt.*}* And he might have added, the shallowness and fallacy of the un- dulatory theory of sound was made apparent. He, how- ever, does express himself as follows: “Assuredly no question of science ever stood so much in need of revision as this of the transmission of sound through the atmos- phere. Slowly, but surely, we mastered the question, and the further we advanced the more plainly it appeared that our reputed knowledge regarding it was erroneous from beginning to end.”:}: How for the other side of the discussion, or to demon- strate what this paper calls for: The Fallacy of the Pres- ent Theory of Sound. To do this it will be advisable to divide the considera- * Helmholtz, loc. cit. p. 235. X Tyndall, loc. cit. p. 328, 329. f Tyndall, loc. cit. p. 257. the fallacy of the present theory of sound. 19 tion of this subject up into different heads. We will therefore consider (1) the Agitation of the Air; (2) Mobility of the Atmosphere', (3) Resonance', (4) Heat ie iron must be moved at least to this extent; which could be easily verified, as Prof. Pood has been able to measure ¥0 o*o 0 0 part of an inch. The mass of iron thus displaced would weigh not less than 729,719,050,612 tons, and would be so moved by the strength of the locust, as it is permeated by its sound in all directions, as in the case of air, and every molecule must perform the wave-amplitude of the theory, or an excursion to and fro. The wave-length would naturally be over sixteen times as great as in air. It would follow from this, if the note were the low E of the double bass, which has forty vibra- tions to the second, that the length of the iron wave would be of necessity 176 feet from crest to crest. It may be well to mention here that Prof. Mayer THE FALLACY OF THE PEESENT THEOEY OF SOUND. 71 states * that a given sound in passing tlirougli tlie atmos- phere and producing its condensations actually increases the “density” of the “compressed half” of the wave -e4-j over the normal density of the air. Applying this, to the determination of the physical strength of the locust we have the modest amount of five thousand million tons; while if the calculation is based on the estimated heat which this pressure must necessarily generate to meet the requirements of Laplace these figures are thrown into the shade, making the physical energy of the locust equal to 132,566,207,938,560,000 lbs., or in round numbers 66,000,000,000,000 tons, f On the theory of Sir William Thomson, the locust could only produce sound according to the law which changes barometric pressure,—that is, by the changes in the weight of the atmosphere,—as will be shown farther on. Therefore, as the locust can be heard over four square miles of the earth’s surface, or over an area of 15,844,448,400 square inches, its mechanical strength, by moving its vibratory apparatus, can add 60,000,000 lbs., in round numbers, to the weight of the atmosphere. For if the barometer rises only one tenth of an inch, it shows that the weight of the atmosphere has actually increased * See Appleton’s Encyc.; article Sound, by Alfred Mayer, f Hall, loc. cit. p. 145. t Sci. Amer. Suppl. fSci. Amer. Suppl. THE FALLACY OF THE PRESENT THEORY OF SOUHD. 34 grains to each square inch on the surface of the earth at that locality in order to produce such change. Surely this fact is sufficient to show the absurdity of the current doctrine of acoustics. Prof. P. Kelso Carter * has made some interesting cal- culations (which do not seem out of place here) in rela- tion to the hell employed by Messrs. Colladon & Sturm under water to determine the velocity of sound. Two questions, says Carter, must be asked: 1. What caused the actual motion of the water? 2. How much was actually (not theoretically) moved ? In this problem the actual amplitude of the supposed vibration of the water-particles is not of the slightest consequence. The fact is the particles moved, and moved at a specified rate [within their amplitude]. Carter deduced the following undeniable facts : 1. This remarkable bell (the sound of which was heard nine miles off) actually set in vibration particles of water in twenty cubic miles [estimated nine miles long and broad, with a depth of one fourth of a mile]. 2. This amount of water weighs 920 trillion tons. 3, The dead- weight resistance offered by this water to every impulse amounts to two trillion tons. (This supposes the impulse to be given at the smallest cross-section.) 4. This dead- * Microcosm, vol. iii. p. 262. THE FALLACY OF THE PRESENT THEORY OF SOUND. 73 weight was positively overcome 400 times in a second as long as the bell was heard. In this calculation, to meet the objection which might be urged that the sounding body only moves the first layer of the water, and the motion is communicated and handed over to the next with some loss, and so on, it makes no difference how thick or how thin a “ first layer” be taken. Carter has taken no thickness at all. It is indisputable that the amount of square surface will offer the resistance he has given. The only questions are: 1. How great is the cross-section of the water moved ? 2. How much resistance to such a rate of motion does water oifer to the square foot ? It is a principle laid down by Archimedes that any force whatever which proceeds or radiates from a centre diminishes as the square of the distance along any given line. How suppose the bell in the above case to vibrate one inch. Then the initial impulse given to the water will be one inch in amplitude. While the molecules of water next the bell will move one inch, no one can invent a reason for the next molecule to move any farther. Applying the above-mentioned principles, Carter finds as the force goes on, at nine miles it would be reduced to irsTo 0000 o o q °f an hieh, which is less than of the diameter of an ultimate molecule, so called, of hydrogen. But as this molecule is supposed to have a vibratory path THE FALLACY OF THE PRESENT THEORY OF SOUND. 200 times its diameter, then the reduced to yfoVof* As the vibratory motion of the hydrogen molecule in its path has never been heard, it is plain that an impulse to affect the auditory nerve must exceed it, as it is about thirty times less. This argument of Prof. Carter certainly settles the locust question, and sustains the deductions made to show what a locust would be called on to do if the wave-theory of sound were correct. THE FALLACY OF THE PRESENT THEORY OF SOUND. 75 The Barometric Theory of Sir William Thomson. As this is the very latest interpretation of the present theory of sound, it seems appropriate to devote a few minutes to its consideration. According to Sir William,* as stated briefly before, sound is “ exceedingly sudden changes of pressure acting on the tympanum of the ear, through such a short time and with such moderate force as not to hurt it, but to give rise to a very distinct sensation which is communi- cated through a train of bones to the auditory nerve.” To explain : It is a “ sudden change of pressure,” and it differs from a gradual change of pressure” as seen on the barometer only in being more rapid—so rapid that we perceive it as sound. If by any means a fall of the barometer could happen “ amounting to a tenth of an inch and taking place in a thousandth of a second,” says Sir William, “it would affect us quite like sound: a sudden rise of the barometer would produce a sound analogous to what ‘happens’ when I clap my hands.” * Sci. Am. Suppl. 76 THE FALLACY OF THE PRESENT THEORY OF SOUND. By means of a regular barometric tube, with its sen- sitive column of mercury completely exposed to the air of a room by removing the cork from the enlarged por- tion of the chamber at its base, so that the slightest change of atmospheric pressure might be instantly ob- served in the rise or fall of the top of the column, the instrument being properly secured at a convenient height for close observation with a powerful magnifier, Dr. Hall, with the assistance of careful scientific witnesses, deduced the following:* that “Ho vibratory or wave motion of the air caused by a moving body, let the disturbances or pulses be slow or rapid, produces the slightest effect upon the barometer even in a closed room, and directly at the exposed mercury, as demonstrated by actual experiment. Therefore sound is not produced in our sensations by air-waves or atmospheric pulses sent off from a vibrating body, and consequently the wave-theory breaks down in the hands of its greatest modern champion.” * Microcosm, Nov. 1884, p. 125. THE FALLACY OP THE PEESENT THEOEY OP SOUND. 77 Elasticity and Density. Tyndall states a supposed law as follows: “ The velocity of sound in air depends on the elasticity of the air in relation to its density. The greater the elasticity the swifter is the propagation; the greater the density the slower is the propagation.” What, then, is elasticity ? It is a property of a body analogous to that of ductility, malleability, porosity, fusibility, etc., and in no manner or degree does it or can it exert mechanical force or aid in overcoming the inertia of a body: “its whole office* being to permit a cer- tain kind of motion or quality of effect through the ap- plication of adequate mechanical force.” So that the elasticity of the air could not add one grain of force to the original mechanical energy of the locust, in the illustration already given, by which it could displace the air by overcoming its inertia. It must of necessity be conceded, if the above law were correct,—if a body could be found having great density and no elasticity,—sound should not travel through such * Microcosm, vol. iii. p. 219, 78 THE FALLACY OF THE PRESENT THEORY OF SOUND. a substance at all. Such a body we have practically in lead, which is one of the densest metals and is almost entirely devoid of elasticity. Miller says : * “By elasticity we understand the resistance that a body offers to com- pression or to extension, and the property which it pos- sesses of regaining its former volume when the pressure or tension is withdrawn.” When heat is applied to lead, its particles are so soft that they slide over each other, according to the current theory, in the act of expansion, and do not return to their original position. A leaden pipe of a few feet long, if used for conveying steam, be- comes permanently lengthened by some inches in a short time, f This would not be the case if lead had more elasticity. How, then, is it possible for lead to transmit sound-undulations 4030 feet per second, as Tyndall states, when the velocity of sound through water is practically the same, or 4Y14 feet ? The density of lead is just about eleven times that of water, and Tyndall says, “ Other things remaining the same, an augmentation of density always produces a diminution of velocity.” Hence the velocity of sound in lead should certainly be very much slower than in water, if it should have any velocity at all, according to the law. Tyndall further states that “ elasticity is measured by compressibility,” as * Chem. Phys., parti, p. 48. f Miller, loc. cit. p. 289. THE FALLACY OF THE PRESENT THEORY OF SOUND. 79 is stated in as many words by Miller’s definition of elas- ticity just given. Which is the more compressible, lead or water, when the coefficient of compression of sea-water is known to be only 0.0000436, and lead, as is known, can be compressed in the cold, being similar to putty ? Professor Tyndall gives the velocity of sound along the fibre of pine-wood as 10,900 feet, and across the rings 4611. ISTow, says Prof. Carter,* in the name of common reason, is not pine-wood infinitely more compressible than water ? Is it not therefore much less elastic ? And is it not also only a little lighter or less dense ? Well, then, put these facts together, and as the densities are very nearly alike, surely the velocities ought to be the same. If it is maintained that the elasticity of the air con- stantly adds force to the impulse imparted to the same by the locust, so that the locust does not have to exert much force to set the atmosphere into vibrations, either, says Dr. B. S. Taylor, “ the doctrine of the unalterable quantity of energy must be given up or else the un- dulatory theory of sound ” must be abandoned. This doctrine, however, is perfectly safe, for elasticity, as already stated, is a mere property of a body and cannot add one grain of force to the supposed work of the locust, * Microcosm, Nov. 1884, p, 104. 80 THE FALLACY OF THE PRESENT THEORY OF SOUND. or the work the locust would of necessity have to per- form if the wave theory of sound were correct; hut as it is not correct, we can protect the locust as well as the doctrine of the constant equivalence of energy. As I have just had occasion to refer to the “ impulse,” it is best for me to say a few words about it, for the majority of people think that all a vibrating body has to do is to start or form a so-called sonorous wave and the “impulse” will safely carry it at the rate of 1120 feet through the air. “An impulse is the effect of a blow,” and “ the measure of an impulse in producing a change of velocity of a body is the increased (or decreased) momentum produced in the body.” “ The work done by an impulse (being) measured in the same way as for finite forces.” All the effects, therefore, says DeYolson Wood, of an impulse are measured in the same way as the total effects produced by a finite force. The idea of an impulse contributing one grain of force over and above, or even exactly as much as, the force that excited it, is absurd. What interests us here is the velocity of an impulse. Newton thought an im- pulse was transmitted through a molecule of a body in- stantaneously. This is incorrect, even according to the present theory of the constitution of bodies. Matter is supposed to be composed of molecules acted upon by at- tractive and repulsive forces. Molecules are therefore THE FALLACY OF THE PRESENT THEORY OF SOUND. 81 not in contact according to tins view. If the distance between the molecules he increased within the limits of the action of the forces, both forces are diminished; and if the distance is lessened, both are increased, but not in the same proportion. Applying these facts, then, a mole- cule of air after receiving a blow is first compressed (which requires time) before it can move towards its neighbor in front of it; and when so moving it excites and increases the forces; the neighboringmolecule is then compressed, each molecule performing its own motion forward and back, and so on until the original force is overcome. From this it is evident that in the trans- ferrence of a pulse a given amount of time is required and a given amount of the original force is utilized to do work. Now, it is a fact that the impulse in an elastic medium travels with considerable rapidity; but such rapidity can be easily ascertained by experiment, and has been done. If the propagation of sound wTas attributed to some other cause than the vibrations of condensations and rare- factions of the air, no physicist would assume (for it is a mere assumption) that an impulse can travel at the rate of 1120 feet a second through air. It is only on account of the first assumption that an “impulse” has been credited with such a wonderful performance. Experi- ments made within the domain of practical limits (leav- ing the consideration of the so-called light-pulses and sound-pulses out) do not justify any such conclusion. THE FALLACY OF THE PRESENT THEORY OF SOUND. Interference and Beats. It is claimed that the so-called sound-waves under cer- tain conditions produce interference, and this is claimed to be especially conclusive evidence in favor of atmos- pheric wave-motion. It is certainly essential to the theory that such interference should exist, as sound- waves, according to Helmholtz and other scientists, are “essentially identical” with and “precisely similar” to water-waves; as when two equal systems of water-waves travel together in such manner that the crests of one system coincide with or fall into the furrows of the other system they will mutually destroy or neutralize each other producing a level, or nearly so. So it is claimed that if the condensation of one wave of sound should fall into the rarefaction of another wave of sound of the same intensity, according to Tyndall the result would be “ absolute silence;” while if the condensation of the one coincided with the condensation of the other, and the rarefactions the same way, then by this “ coinci- dence” a sound will be produced which will be four times the intensity of either. This supposed law of interference of sound-waves has no foundation in science THE FALLACY OF THE PRESENT THEORY OF SOUND. 83 or fact, as I will now undertake to show; and if I succeed in doing so, the so-called wave-theory will not have a foundation to stand on. The double siren, which must be familiar to you all, is an apparatus by which it is claimed that the so-called interference can be demonstrated. To use Tyndall’s own words :* “ Where the circle is perforated by 12 orifices, the rotation through of its circumference causes the apertures of the upper wind-chest to be closed at the precise moment when those of the lower siren are opened, and vice versa. It is plain, therefore, that the intervals between the puffs of the lower siren, which correspond to the rarefactions of its sonorous waves, are here filled by the puffs or condensations of the upper siren. In fact, the condensations of the one coincide with the rarefactions of the other, and the absolute extinction of the sound of both sirens is the consequence.” Tyndall further states that this statement may seem to exceed “ the truth; for when the handle is placed in the position which corresponds to absolute extinction, you still have a distinct sound.” He claims that the “aerial disturb- ance breaks up into secondary waves which associate themselves with the primary waves of the instrument.” The turning of the upper siren through FT of its circum- * Tyndall, loc. cit. p. 291. 84 THE FALLACY OF THE PRESENT THEORY OF SOUND. ference utterly extinguishes fundamental tone. But we do not extinguish its octane. To discuss the merits of this seems too absurd, for “ In the name of science and reason—in the name of acoustics and common-sense— what should have been expected but this very result V * By operating the two sirens together, so that the 12 puffs of the upper siren alternated with the 12 puffs of the lower siren, surely 24 puffs were obtained the same as if he had used one siren with 24 holes instead of 12. The result of necessity must be the raising of the funda- mental note to its octave. Tyndall should have known this instead of resorting to talk about “ secondary waves associating themselves with primary waves,” etc., when he distinctly teaches that no octave, from whatever instrument, can be produced without doubling the number of vibrations which caused its fundamental tone. Prof. Helmholtz was the first to make the mistake. He says :f “ The puffs of air in one box occur exactly in the middle between those of the other, and the two prime tones mutually destroy each other. . . . Hence in the new position the tone is weaker because it is deprived of several of its partials [over-tones]; but it does not entirely cease; it rather jumps up an octave.” We have heard the reason why “ the tone is weaker” in the * Hall, 100, cit. p. 288. f Helmholtz, loc. cit. p. 240. 85 THE FALLACY OF THE PRESENT THEORY OF SOUXTD. new position according to Helmholtz and Tyndall, and now we will hear the true explanation given by Dr, Hall: That the weaker tone is due simply to the fact that it was constituted of a single series of 24 successive puffs or vibrations to a revolution, while the prime tone was composed of two series of 12 double or unison puffs which necessarily re-enforced each other, and by which means their intensity was increased fourfold.* Prof. Tyndall showed how the number of vibrations of a particular fork could he ascertained by the siren. He says the siren makes 334 puffs of air in a second, and he further distinctly says that one puff is one wave of sound. "With the siren, then, a single puff of air escaping through a hole in a disk constitutes a vibration, or a pulse, or a sound-wave. But with the fork the case is very different. Here we see that a single puff or motion does not constitute a vibration, but only half a vibration.f In the matter of the siren, says Prof. Carter, £ 384 puffs of air issue from a tube in a second. Each puff is a motion forward from the mouth of the tube; there is no backward motion in any sense whatever. How we would like Prof. Tyndall to explain how a puff of air, that has only one motion “ to” and not “ fro,” can, by his own definition, be called a wave of sound or f Tyndall, loc. cit. p. 69 * Hall, loc. cit. p. 295. % Microcosm, Dec. 1883, p. 145. 86 THE FALLACY OE THE PRESENT THEORY OF SOUND. a vibration. He insists on it that a vibration mu consist of two motions equally distinct, one forward and tbe other backward, or else it is only a “semi-vibra- tion.” The puff is not suddenly checked and reversed as in the case of a fork’s prong, but is left to expend itself against the yielding atmosphere. The stream is sud- denly cut off, but no one will be so foolish as to claim that the stoppage of the supply of wind is a reversed motion. If it is, then the stoppage of wind constitutes the vibrating body, for the Professor assures us that the vibrating body must make the “ excursion to and fro.” If any one declares that the starting and stopping of the air constitutes the necessary double motion, they can be referred to the tuning-fork, which manifestly stops and starts at each end of its swing, or four times in a complete excursion to and fro. The facts are that the puff of air makes only a “ semi- vibration,” or a single motion forward, while the fork- prong makes a double motion “ to and froand notwith- standing this difference, the siren and the fork produce precisely the same note when listened to in the ordinary way. The siren produces sound by using the air itself as the agent, and conveys the sound through itself to the ear. In this case one motion or semi-vibration produces the THE FALLACY OF THE PRESENT THEORY OF SOUND. 87 effect on the ear of certain notes in the scale. The fork produces sound in itself and does not convey this sound to the ear at all, hut is forced to hand it over to another medium, air, to convey it to the ear. In this case a double vibration is necessary to produce the same note. Prof. Carter asks the following question: If sound is produced by a vibrating piece of steel, and were my ear buried in the steel itself, would I hear anything? By the aid of Tyndall’s admission that a single air-puff actually produces the same effect on the ear as a double fork-vibration, Carter has been able to discover that “ When the ear is in the vibrating body a single or semi vibration produces the same effect as that produced by a double or complete vibration when the ear is not in the sounding body.” If two unison * forks be sounded over the resonant jars of proper depth placed one half a wave apart, their tone can be heard exactly the same in line as at right angles, or when a whole wave-length apart; while according to the testimony of Prof. Helmholtz the very highest authority on the subject, such sounds are destitute of accompanying over-tones. The necessity for referring to “ clang-tints” or “ over- tones” of the “ highly composite” siren resulting from * Hall, loc. cit. p. 287. 88 THE FALLACY OF THE PRESENT THEORY OF SOUND. its “ secondary waves- whicli associate themselves with the primary waves” is at once dispelled. The real value of the siren, then, is to show that the pitch of every fun- damental sound, from whatever instrument, corresponds precisely to the number of vibrations in a second which generates the tone.* Let ns consider for one moment a harp-string. Here we have condensations sent off on one side by the very identical motion which generates and sends off the rare- factions on the other side of the string, and at exactly the same instant of time. So that, according to the theory of interference by half wave-lengths, the rarefactions on one side of the string would react and reflect upward a given distance, just in time to coalesce with the con- densation from the other side, since they occur synchro- nously and both travel with the same velocity; and hence the two systems of waves from the two sides of the string must necessarily produce complete interference and cause “absolute silence” in a vertical direction, if there is a shadow of truth in the wave-theory. It seems needless to say you know that no such in- terference takes place. It may be advisable to refer briefly to the apparatus of M. Koenig, the principle of which was first proposed by Sir John Herschel, the ob- * Hall, loc. cit. p. 303. THE FALLACY OF THE PRESENT THEORY OF SOUND. 89 ject being to divide a stream of sound into two branches of different lengths and afterward cause the branches to reunite and to interfere with each other. Koenig’s ap- paratus, which must be familiar to you, carries out this idea. Tyndall states that when the parts are properly adjusted the sound of a fork is extinguished. This statement is false, for no such thing as silence occurs, since the sound of the fork is not diminished in intensity more than one quarter, as any sound-expert would readily admit; and by a modification of Koenig’s instrument the effect has been proved to be due to the result of resonance, and due to either the re-enforcement or op- position of the two vibrating air-columns of the two tubes; * and it has been further shown that any resonant effect produced by dividing the sound into two streams ean be equally obtained by a single stream in connection with a closed resonant tube of certain depth. As the Koenig apparatus has always been considered as con- clusive evidence in favor of this law of interference be- tween sound-waves, scientists cannot help but be in- debted to Dr. Hall for exposing its fallacy and thus annihilate completely the supposed law of interference, the very foundation of the present wave-theory of sound. * Hall, loc. cit. p. 311. 90 THE FALLACY OF THE PRESENT THEORY OF SOUND. Beats. If we employ two organ-pipes which give slightly differ- ent tones, assuming both their waves start fairly together, the supposed condensations and rarefactions being in har- mony, this state of things cannot long remain so, owing to the inequality of their length. Hence in this experi- ment we must expect to have alternations of sound and silence, the tone rising and swelling to a maximum, then dying away again to repeat itself, etc. These alter- nations are called beats, and furnish even to the un- musical ear a very accurate means of judging of the identity of musical tones. According to Helmholtz, discord is due to the presence of the beats; and Hood * states “ that when from any cause these beats follow each other at the rate of about 33 in a second the discord is at its maximum, becoming more tolerable with twice this number, and finally disappears altogether as their number is increased to about 120 in a second. On the other hand, if the beats follow quite slowly—for example, at the rate of three * Johnson’s Cyc. THE FALLACY OF THE PRESENT THEORY OF SOUND. 91 to five in a second—the effect is not unpleasant, and can even be employed in music, suggesting as it does the idea of trilling. It is evident from tins that the sinking and swelling of the sounds of two beating instruments result “ alone,” according to the wave-theory, from the alternate coincidence or interference of the air-waves themselves sent off from such sounding bodies. This I deny, as I have clearly shown that no such interfer- ence between two supposed systems of air-waves can take place, since not the slightest weakening of two unison tones occurs when two vibrating bodies are sounded half a wave-length apart. Dr. Hall * maintains that the operation which alternately augments and diminishes the intensity of tone, as the oscillations of two forks cross each other’s path in changing from synchronous to alter- nate vibration, has nothing to do with air-waves or any motion of the air-particles whatever, but takes place in the instruments themselves or in their potential and practical sympathetic attraction for each other, without regard to the coincidence or interference of such useless nonentities as these so-called atmospheric condensations and rarefactions. Suppose, for example, two forks mounted upon their resonant cases and tuned sufficiently out of unison to pro- * Hall, loc. cit. p. 305. 92 THE FALLACY OF THE PRESENT THEORY OF SOUND. duce, say, one beat to the second. If sounded in close proximity to each other or in a position of strong sym- pathetic attraction, a listener stationed a hundred feet away from them will distinctly hear their beats—will in fact hear them as far away as the sound of the forks is audible. But let the two forks while sounding be quietly separated only a few feet toward the right and left of the listener, and though he will continue to hear their united sounds in full force, yet the beats will entirely cease, showing that they result from the sympathetic influence of the two forks upon each other owing to their affinity, and not to the alternate interference and coincidence of the two systems of supposed air-waves a hundred feet away, or at the ear of the distant observer, as the wave- theory teaches. THE FALLACY OF THE PRESENT THEORY OF SOUND. 93 The Membrana Tympani and the Corti Arches. The description of the membrana tympani has been given already, so only a few additional facts will be of interest. The upper border * of this membrane is 7 mm. nearer to the entrance of the external auditory canal than the lower. The posterior border is about 5 mm. nearer this, entrance or meatus than the anterior. It makes an angle of 55° with the axis of the auditory canal. Its general shape is elliptical or funnel-shaped. The horizontal diameter is Bto 8.5 mm., and vertical 8.5 to 9 mm. Its thickness is not quite 0.1 mm.; in other words, about the same as very fine letter paper. Mr. Shrapnell considers the function of the membrana flacceda is to protect the more tense fibres, deadening the effect of the sudden and loud sound, or of coughing and sneezing, when by yield- ing it saves the tense fibres from being ruptured. In the hare and sheep, whose sense of hearing is very acute, this structure is remarkably developed, f The existence of a, * St. John Roosa, Diseases of the Ear (1884). f London Med. Gaz., vol. x. p. 120. 94 THE EALLACT OE THE PRESENT THEORY OE SOUND. minute opening in the membrane at its upper margin called the Eivinian foramen has been proved, as air may be occasionally heard to whistle through it, although it cannot be seen by the unaided eye.* Double hearing sometimes occurs, and Mr. Homes ex- plains it by a defective action of the radiated muscle, which was not exerted with the same quickness and force in one ear as in the other, so that the sound was half a note too low, as well as later in being impressed upon the organ. Nearly all such cases observed are amongst musicians, f The membrana tympani when viewed through the auditory canal shows a triangular spot of light. The apex of this spot is at its greatest concavity and is called the umbo, and is due to this and the inclination of the membrane. It is reflected light.:}: According to Dr. St. John Eoosa, § “the presence of the membrana tympani in whole or in part is not essen- tial to fair hearing power.” This was first clearly proved by Sir Astley Cooper, |( Eoosa, however, says “ that it is very important to good hearing in some cases, [as] is shown by the numerous in- * Kessel-Stricker, Handbook of Histology, p. 953. + Phil. Trans, of Royal Soc. London, 1880, pt. i. % Politzer, Membrana Tympani, p. 26. | Phil. Trans. London, 1800, p. 155. § Loc. cit. p. 252. THE FALLACY OF THE PRESENT THEORY OF SOUND. 95 stances in which an artificial membrana tympani raises the hearing power from a very low degree to a higher one.” This fact can be readily explained, and will be below. Sir Astley Cooper * was the first to puncture the mem- brana tympani to cure deafness, and he cites four cases which by such treatment were made to hear distinctly. Hunold punctured every membrana tympani to which he could get access, and he reported the brilliant result of curing or improving seventy cases out of a hundred. While this has been questioned, Michaelis succeeded in improving the hearing of 3300 of the cases treated by him. Karl Himly wrote a commentary upon the opera- tion, to show that it was only in exceptional cases that puncturing the membrane was of any value. The truth of the matter, as it appears to me, is that if it were not for the middle or inner ear being liable to get inflamed or diseased, the puncturing of the membrane would be performed very much oftener than it is. Sufficient cases on record prove, however, what we are more interested in—that, for the perception of sound, the membrana tympani can be completely removed and the subject will hear as well, if not better, without it as with it. Therefore the beautiful idea of the necessity of the * Phil. Trans. Royal Soc. London, 1801. 96 THE FALLACY OF THE PRESENT THEORY OP SOUND. tympanic membrane vibrating once in and once out for each vibration and being hit harder by the air-particles to produce intense notes than if notes less intense are sounded, or the idea that such membrane is necessary at all except to oblige a supposed wave-theory, I think from the above is clearly established, as the medical student re- ferred to by Sir Astley Cooper in his work lost his tympanic membrane but could hear very well. The real value of the tympanic membrane is then simply to keep the cold and dust out of the middle ear, which otherwise might become inflamed or diseased. Just imagine how accommodating, says Prof. Cox,* the tympanic membrane is supposed to be by the high authorities. If the notes C 2 (256 vibrations), E2 (320), G2 (384), and C 3 (512) of the piano be struck simultaneously, according to the wave-theory this membrane is supposed to vibrate within the same second in and out 256, 320, 384, and 512 times. And each sound-wave is supposed to go through the air as if it alone were present. Does this not look absurd, and is it not a valuable discovery which proves that sound-perception does not depend on the vibration of the membrana tympani at all ? When the middle ear is diseased, the hearing can be benefited by a hearing-trumpet or audiphone. * Microcosm, Sept. 1884, p. 60. THE FALLACY OE THE PRESENT THEORY OF SOUND, 97 Sir "William Thomson in his lecture coolly instances a case of a deaf man hearing music by holding a stick be- tween his teeth pressed against the piano while he was playing it, not seeming to recognize the fact * that this conduction of sound to the auditory nerve by means of the solid bones of the head was a flat overturn of his pretentious barometric philosophy. Prof. Helmholtz states that the drum-skin, as well as every other membrane, must have some definite pitch as the “ the vibrational number of its own proper tone hence has claimed to have proved that this membrane is toned to a relatively deep note as a result of its funnel- like shape. He says that the tone cannot be exactly de. termined, but it is certainly not higher than 700 vibra- tions. So that if the highest note but one in a seven- octave piano-forte (G), with 8400 vibrations in a second, should be sounded, the tympanic membrane at once is coerced into an abnormal rate of nearly 3000 oscil- lations out of tune, assuming the vibrational number of the membrane to be 440, or the note A, and this too by “ sympathetic vibrationand then, contrary to all known mechanical or acoustical laws, it drops that motion and takes up a new rate of 440 vibrations a second, without any known or exciting cause whatever to superinduce it, since * Hall, loc. cit. p. 304. 98 THE FALLACY OF THE PRESENT THEORY OF SOUND. we are told by Helmlioltz tbat “ as soon as the exciting tone ceases it goes on sounding in the pitch or the vibra- tional number of its own tone.” “ Hence A must be sounding,” says Hall, “in my ear as a perpetual monotone,, while an orchestra is playing, filling up every interval which occurs in any piece of music I hear.” As the vibrational number of any stretched membrane depends on its size, weight, and tension, and as it is evident that no two drum-skins can combine these ele- ments to exactly the same degree in different individuals, it follows that with one person A would be the pre- dominant or loud note, with another B or Bb, with an- other C or Off, with another D, and so on through the chromatic scale, or possibly through several octaves. Fortunately, however, such trash as this need not confuse us, as I have already shown that the tympanic membrane can be punctured or removed and the subject will hear as well, and in many cases better, without it as with it. A word before closing, in relation to the rods of Corti, which have already been referred to in the first part of this paper. Helmholtz insists that they “ must be dif- ferently tuned and their tones form a regular progressive series of degrees through the whole extent of the musical scale.” The “ differently tuned ” strings of a piano-forte in order to produce its seven octaves are not only compelled to vary in length from feet to If THE FALLACY OF THE PRESENT THEORY OF SOUHD. 99 inches, the difference being as Ito 40; the size and weight must also differ, the weight of the highest and lowest strings of the piano-forte in order to “form a regular progressive series of degrees through the whole extent of the musical scale” being 1 to about 1600, Hensen, however, shows that the difference between the longest and shortest of these Corti rods is only about one half, or as 1 to 2, while no perceptible difference in size is recorded which is necessary in the strings of a piano- forte. C. Hasse has shown that these microscopic pro- cesses, so essential to the wave-theory of sound, have no existence at all in the ears of birds ! Yet the mocking- bird can distinguish, analyze, and imitate the finest shade of pitch equal to a prima donna! Away, then, to the winds goes the Corti lute of 3000 strings, as Prof. Tyndall calls it. As regards the unisonant vibration of the antennse or so-called “auditory hairs” of the mysis or opossum- shrimp, as also the vibration of the so-called variously tuned fibrils of the antennse of the male mosquito as spoken of by Mayer,* these motions must be regarded as simply reactive instead of unisonant, being first heard by the animal through the proper auditory organs with- out any motion whatever of such parts, and then reflected * Am. Jour. Sci., Aug. 1874. 100 THE FALLACY OF THE PRESENT THEORY OF SOUND. back upon the antennae or fibrillae through the nervous system of the creature, thus causing the tremor which is noticed by experimenters as the supposed direct result of unisonant action. The filing of a saw or some peculiar scraping movement of a slate-pencil, for instance, will often react through the nervous system unpleasantly upon the teeth, and with some temperaments, so to set them on edge as to be almost unendurable. No one, of course, would suppose that such impressions on the teeth could occur from the direct or objective action of sound- pulses, since a deaf person would perceive no such effect. Let scientists, says Dr. Hall, test the question of unisonant vibration of antennae on a dead opossum- shrimp or a mosquito, if they wish to show the absurdity of their deductions. THE FALLACY OE THE PRESENT THEORY OE SOUND. 101 Conclusion. In conclusion of tins lecture, I would state that numerous other arguments could be added to show con- clusively the fallacy of the wave-theory of the sound, but time will not permit; and I question whether any more arguments can be necessary, for Prof. Huxley * has said; “ Every hypothesis is bound to explain, or at any rate not to be inconsistent with, the whole of the facts it pro- fesses to account for; and if there is a single one of these facts which can be shown to be inconsistent with (I do not merely mean inexplicable by, but contrary to) the hypothesis, such hypothesis falls to the ground—it is worth nothing. One fact with which it is positively in- consistent is worth as much and is as powerful in nega- tiving the hypothesis as five hundred.” My object this evening, as I have stated before, was to show the fallacy of the wave-theory of sound first demon- strated by Dr. Hall, and to point out just such facts as Huxley speaks of, and to show that it is a fallacy of science handed down from age to age like the Ptolemaic * Origin of Species, p. 140. 102 THE FALLACY OF THE PRESENT THEORY OF SOUND. system of astronomy till a Copernicus arose, and his aide- de-camp Galileo, to show the world a more excellent sys- tem. Now, gentlemen, while I submit the arguments and facts presented in this paper to your careful considera- tion, with the hope that you will weigh the facts and mathematical deductions with the greatest of care and with the one view before you of searching for truth and accepting the same when found, I am willing to risk the fallacy of the wave-theory upon the correctness of one single objection, and that is the slow instead of swift movement of the tuning-fork when sounding audibly and its inability to produce sonorous sound-waves at all as required by the current theory of acoustics. If any scientist can fairly and logically meet and answer this argument, I will gracefully acquiesce. Otherwise the wave-theory should be abandoned at once as a mistake, for one single fact which is positively op- posed to an hypothesis, according to Huxley, overturns it as completely as would five hundred such opposing facts. I know some scientist will say, We adopt the current theory provisionally for want of a better one. This I pro- pose to give at some future time. All that I ask now is to have the fact admitted that the wave-theory is falla- cious. lam satisfied that there are scientific men who have so much faith in the correctness of the wave-theory THE PALLACY OP THE PRESENT THEORY OP SOUND. 103 of sound that it would be difficult to convince them that the theory could be incorrect. Their faith might be lik- ened unto the Arabic adage: “If the pitcher fall on the stone, so much the worse for the pitcher; and if the stone fall on the pitcher, so much the worse for the pitcher”—always worse for the pitcher, or for any argu- ments which attack a theory that has been upheld for 2500 years, and more especially when such theory has been and is sustained by the ablest living scientists. Let the investigation commence, but do not waste time attacking the less important points; proceed at once to the strong ones, such as the arguments referring to the tuning-fork and to so-called interference, and let the world know whether the wave-theory is the stone or whether it has been shown to be the pitcher by the argu- ments advanced this evening.