286 



NATURE 



[July II, 1878 



with the rhythmical flow of the undulations of sound, 

 they must be poised off from the walls of the auditory 

 sac. And this is effected, in some instances, by little 

 tubercles on the inner surface as in the ..utile fish or as 

 in the Heteropod, as shown in Fig. 5 {h), the auditory 

 organ of Cerophora, in which also large vibratile cilia 

 effect a continual rotatory motion of the spherical otolith. 

 In other cases when otoconia are present, a fine ciliated 

 lining not only prevents the contact of these minute par- 

 ticles with the walls of the sac, but keeps them in 

 constant motion, jostling one another in a remarkable 

 manner. Now when acoustic waves are passing over the 

 auditory organ, it is easy to perceive how their impulses 

 may be imparted to the otoconia, and thereby com- 

 municated with augmented effect to the auditory centre. 



Whatever may be the intrinsic nature of nervous force 

 it exhibits unmistakable polar properties which would 



SigJ. 



^V«- 



hearing, the study of the anatomy of the ear might give 

 electricians some valuable hints as to the construction of 

 transmitting apparatus. One of Prof, Hughes' transmit- 

 ters so exactly resembles the natural arrangement of the 

 parts in the middle ear of the higher animals, that some 

 few remarks on this subject may not be out of place here. 

 Many years ago (1847-48) I noticed that a small piece of 

 steel casually lying in the box of a square pianoforte 

 reproduced, with great fidelity, any note, or number of 

 notes, touched on the instrument, by the impact of its 

 own weight meeting the vibrations of the sound-board 

 beneath. Here was, in effect, the basis of the telephone, 

 and I would indeed have anticipated the wisdom of the 

 age had I known how to call in the aid of electricity in 

 the simple way that this has been done by Prof. Bell. The 

 fact, however, was made the subject of a paper published 

 in the Medical Gazette^ in which the Membrana iympani 

 and the Malleus were compared with the sound- 

 board and steel rod in the case referred to. 

 Moreover, the inference was drawn that while 

 the membrane communicates its vibrations to 

 the ossicles, or small bones, it also causes the 

 malleus to percuss the face of the incus respon- 

 sively to the rapid and varied impressions made 

 upon it, a view which borrows additional weight 

 from the fact that in the frog articulation is still 

 persistent where, from the absence of muscles 

 for adjustment it might be considered to be 

 quite unnecessary. 



It should also be remembered the handle 

 of the malleus extends like a radius from the 

 centre to the circumference of the drum mem- 

 brane, so as thus to include, without impeding, 

 its three vibrating segments. The centre gives 

 the key-note the circumference the fifth, and 

 the intervening region the third. Only add to 

 this the aural lens or lenticles, the otoliths, or 

 the otoconia, with the light which the microphone 

 has cast upon their function, and we are enabled 

 to form a better conception of the physiology 

 of hearing than has hitherto been possible. 

 The accentuations, piano, forte, &c., in musical 

 pieces, are marked with extreme accuracy, and 

 should the parts of the music be deranged by 

 a defect in time, an uneasy jog will be produced 

 in the auditory apparatus, hence the antipathy 

 of the mind to any erratic deviation in this re- 

 spect. It is very remarkable that the malleus 

 and incus (the hammer and the anvil) should 

 correspond not only in figure, but also in func- 

 - , - . . „ , . , ^ , tion, to the objects from which their respective 



^''p?,u";J"oth°e^ ofvariabielb^." • "' °' " ' ""' ~"" names are derived, for as we have already seen, 



Fig. 4.— Auditory sac of i^iV(7rj«a, Geomeiania, or Cydosioma. the uscs of the hammer and anvil, as employed 



Fig. 5.-Cerebroid ganglia and organs of vision and hearing in Cerophora. a, upper ■ mechanics, are literally fulfilled by the malleUS 

 cerebroids; b, lower cerebroids ; c, buccal nerves; d, motor nerve of the eye; e, "' , • " -^j " ^ v / ] j • .1. 



optic nerves ; /, trunks communicating with the pedal ganglia ; g, pedicle of the and tnCUS answering very important ends in tnC 

 auditory sac; ^', nerve distributed to the auditory sac ; A, auditory sac with contained faculty of audition. By the aCtion of One upon 

 " meniscus, and lens of the eye ; ,t, body of the eye ; /.retina. «.u~ ^fUot- o^.tr./le ' 



Fig. I.— Auditory sac of Nautilus, a, otoconial particles, elliptical. 

 Fig. 2. — Section of auditory cavity of Sepia, with a somewhat cruciform otolith. 



otolith ; 



thus place it in the category of the electric force, though 

 no one now would attempt to reason out the identity of the 

 two. It is, however, a new idea that nervous force in the 

 function of audition plays an analogous part to the electric 

 force in the case of the microphone. Moreover, if we 

 look to the anatomy of the ear, we see that provision for 

 a complete circuit is made. Take, for example, the 

 auditory sac {h), pedicle {g), and nerve {g') of Cerophora 

 (Fig. s). Nothing would appear to be wanting if we ad- 

 mit the nervous centre to be the equivalent of the battery. 

 From all this it would seem to be a rational hypothesis 

 that nervous force in traversing the circuit just indicated 

 under the influence of sonorous undulations is actually 

 transmitted from particle to particle of otoconia, or through 

 the revolving otolith, as the case may be. But while the 

 microphone, or the principle involved in it, affords us 

 some additional light in relation to the physiology of 



the other, sounds are not only correctly trans- 

 mitted to the auditory centre, but an accurate register of 

 time, grace, and style, is effected in the manner above 

 explained. Thus the physical organisation itself may be 

 shown to be the natural preceptor of the mind.^ 



» Dr. F. de Chaumont writes as follows : — 



Since Dr. Macdonald's paper was forwarded to you the appearance of 

 Mr. Blyth's has added still stronger confirmation to the analogy between 

 the microphone and the auditory apparatus of the moUusca, &c. One point 

 in particular is the necessity of moisture of some kind or other, as a medium 

 between the conducting particles, shown b> the fact that even the watery 

 vapour from the breath of the experimenter produced a sensible increase m 

 the strength of the sounds elicited ; and further, that the addition of simple 

 water to the cinders was productive of still more striking effects. AH 

 this bears out the view taken by Dr. Macdonald that we have in the otoconia, 

 endcly}nph and vestibule of the ear the most complete type of a microphone. 



It would be well to try the free suspension of good conducting particles in 

 a non-conducting fluid medium, sufficiently Lmp^d to offer the least possible 

 impediment to their movement. , ■ 1 „. „i,. 



The oscillation of the transmitter as a whole by mechanical means ought 

 also to be tried in order to imitate the effect of vibratile cilia in the case of 

 the auditory vestibule of animals. F- dk Chaumont 



Army Medical School, Netley, June 20 



