Progressive development came with time and the closed canal became an open one, extending to the outer world. Its inner end closed by a membrana tympani formed a boundary to a middle ear which Eustachean tubes supplied with air. Crocodiles had three such tubes though two sufficed for other ears.* In birds they are connected with each other, and those of the horse and porpoise with large air chambers.* Reptiles had a cochlea, not the fairy wonder house of man, where microscopic cords pick out their mates and swing in unison with each musical tremor from the outside world, but a short straight or slightly twisted canal, which in birds doubled upon itself, and in still more perfect organizations coiled around a cen tral axis. Fig. 5. From "Smith & Horner." Magnified view of the nerve taken out of the cochlea, showing the gradual shortening of vibratile fibres. There are two and a half such convolutions in our own ears, yet the huge whale rolling in his billowy home has but one and a half.† A rudimen The external ear first appears upon the crocodile. tary affair that totally failed in adding beauty to his open countenance; and the birds, sweet singers of the woods, cock their heads knowingly to listen with but a fold of skin or radiated arrangement of feathers to assist audition. Necessity seems to have adapted the shape, size and mobility of the external ear to the habits and needs of each individual. Thus, the ears of the carnivora are usually erect and turned forward to facilitate pursuit, of herbiferous animals backward, and often enormously developed and in con * Marshall. Huxley and Henle. Todd and Bowman. * stant motion to catch the least intimation of danger.* They are but slightly developed in the beaver and otter, and wholly wanting in the seal and mole. The water-loving elephant has a valve-like fold of the auricle that closes the meatus at will, and effectually preserves it from injury. The ear is not always located in the head.f In certain locusts it is situated in the front legs,† in several species of grasshoppers in the hind legs, in crickets in the first abdominal ring, in the antennæ of some insects, at their base in others, and in the middle pair of tail plates in the myses. Such ears may not receive the vibrations of sound as accurately as more perfectly organized ones do, but the experiments of Henle go far towards proving that even the humble mollusk's ear is not insensible to a difference in musical tones. Our knowledge of the ear has been of exceedingly slow growth. Hundreds have written about its anatomical structure, and the foundation of its various parts since the days of Hippocrates, and a hasty résumé seems necessary in carrying out the plans of this essay, and may not prove uninteresting to our hearers. The membrana tympani was described by Aristotle, B. C. 384. The facial and acoustic nerves as entering the meatus auditorious internus by Galen, A. D. 130. The meatus externus by Al-Rasi, A. D. 193. The incus and stapes by Achillini, 1480. The Eustachean tubes by Vesalius, although credited to Eustachius, in 1574-8 The long process of malleus and vestibule by Andreas Vesalius in 1542. || The mastoid cells and their communication with the tympanum by Gabriel Fallopius. The fenestra rotunda and Ovalis by the same investigator in 1546. The tensor tympani, the Strapedius muscle and the Cochlea were described (the latter imperfectly) by Bartolommeo Eustachius in 1565.¶ Marshall. + Packard. § Turner, Encycl. Britann. Rossa gives 1514, but as must be an error. Turner, Rossa gives 1512. he was born in that year (Am. Cyclopedia), this Cyclopedia of Anatomy and Physiology, Todd. Rossa on the ear. The fluids in the labyrinths and their necessity were shown by Dominic Cortugno, 1661. The Ceruminous glands by Nicholas Steno, 1665. The Osseous Labyrinth and the membranous labyrinth in 1800 by Antonio Scarpa. Corti's Organ, the Lamina Spiralis membranacea and Cochlea in 1851 by Corti. This brings us down to our own times and the researches of Helmholtz, Striker, Henle, Von Troltsch, Muller, Hyrtl, Wilde, Kramer, Pilcher, Yearsley, Gruber, Weber, Moos, Sommering, Kolliker, Bowman, Toynbee, Lucas Championniere, M. Allen Starr, and a few earnest searchers, aided by perfected scientific appliances, have left little unexplained about our organs of hearing. Now I turn a hasty glance towards the gradual growth of Aural Therapeutics. In the earlier ages the treatment of the ear and its diseases was crude and illogical, and often a mere senseless groping in the dark, although an occasional gleam foreshadowed the treatment accorded in our time, and we can scarcely appreciate the present status without knowing something of its past. The installation of warm water or warm oil was recommended by Hippocrates, B. C. 570. Asclepiades, a mixture of cockroaches, snails and woman's milk in oil. Celsus, A. D. 19, the removal of foreign bodies by the injection of water. Archigenes bled, purged, and used warm fomentations for pain in the ear. Speaking tubes were advised by him. In A. D. 140 Galen ordered the secretions of the nose and mouth to be excited for deafness, and described tinnitus aurium, and prior to his time, spoons, forceps and hooks had been used for removing foreign bodies from the ear as well as shaking the inverted body to assist. Marcellus ordered "Frogs' fat, pigs and human urine, and the blood of chickens" in the ear. Six hundred A. D. Paulus Æginita detached the auricle from the canal by an incision behind to remove foreign bodies, when other means failed. Gadesden directed the meatus to be sucked out, and in 1590 Johannes Arcularius advised the head of a lizard to be cut off and + Loucke's Handbook. placed in the affected ear; when removed, any foreign body would be found in its mouth. Gabriel Fallopius believed an otorrhoea to be a discharge from the brain. He used an Aural Speculum. Gilbert Horst used water distilled over a young mouse having no hair, in the ear for deafness. He was director of a hospital in Rome. The syringe was first ordered for cleansing the ear in 1577 by Ambrose Pere. An artificial ear-drum of pig's bladder was proposed in 1640 and later in the century T. Willis showed that perforation of the membrana tympani did not cause total deafness. Gleams of light occasionally shone in this darkness and the education of the deaf mutes was one, when commenced by John Wallis. In 1542 Valsalva recognized anchylosis of the base of the stapes, gave the Valsalvian experiment, and knew that closure of the Eustachian tube was a frequent cause of deafness. In 1774 Petit advised opening the mastoid cells in certain cases of suppuration in the ear. In 1735 Guyot the Postmaster opened his Eustachian tubes by an instrument of his own invention and restored his hearing. Cooper, in 1800, proposed perforating the membrana tympani in ulceration. Yearsley in 1841 improved hearing in cases of perforation of membrana tympani by inserting a pellet of cotton. In 1843 William Wilde, published his work on the ear, and otology became a science. Heretofore the treatment of deafness had been purely empirical, and deafness the result had been treated, not its cause. From the dim past it had been a blind groping in the dark and its lack of success proverbial. Since the birth of otology how changed. Means of closely examining the meatus externus, membrana tympani and the posterior naries have been discovered. We can reach the tympanum, Eustachian tubes, nasal cavities, and pharyngial mucous membrane with remedial agents. New causes of deafness have been recognized and the appliances devised to obviate them. These discoveries have not resulted from the labors of one man. Toynbee, Von Trolsch, Pilcher, Sales, Giron, Bergson, Knapp, Turnbull, Roosa, Williams, Blake Green, Czermak have enveavored to raise otology to a stand co-equal with opthalmology. True, few new facts have been discovered, but the experience of the fathers has been accepted, adjudged, the wheat culled and the chaff abandoned. Symptoms indicative of diseases that are liable to produce deafness are recognized, invaluable aids to assist in diagnosis and treat ment perfected, and hope now exists for many who once would have been hopeless." *“Time and research have perfected a theory of sound and of hearing as perfect in detail as it is beautiful of conception. The views now entertained by the most eminent authorities regarding the change of motion into sound which constitutes the act of hearing may be briefly described as follows: Waves of sound originated by some sounding body ripple through the intervening air into the auditory passage and strike against the ear-drum just as positively as waves of the ocean dash upon a rocky shore. "The thin membrane shivers under the concussion and its tiny undulations are transmitted through the osseous chain of the middle ear to the membranous pane of the ovalis against which the base of the stirrup bone abuts and excites concentrated vibrations in the fluids of the labyrinth. The auditory bristles are set vibrating and stir the nerve fibres which lie between their roots and excite audition. The little otolithes prolong the vibrations, the vesicular branches of the auditory nerve are stimulated and the Cochlear branches of the auditory nerve are excited to conduct sound impulses to the brain. Here the wonderful organ of Corti (which is to all appearances a musical instrument with its cords so stretched as to receive vibrations of different periods) analyses those impulses and renders them fit for recognition by the brain. Each tremor which falls upon this lute of three thousand strings selects from its tensioned fibres the one appropriate to its own pitch and throws it into unisonant vibrations, and thus, no matter how complicated the motion of the outer world may be, those microscopic strings can analyze them and reveal the constituents of which each is composed. We are scarcely conscious of the myriads of sound waves generating by the numerous bodies that surround us. They are constantly agitating the air just as the surface of the Hudson is carved by waves and ripples innumerable, and still each wave and every ripple ascertaining its right place and retaining its individual existence among the crowd of other emotions that agitate the water; so the air we breathe and through which we move is competent to accept and transmit the vibrations of a thousand instruments at the same time, but when we try to analyze the emotions of the air, to present to the eye of the mind the battling of the |