SPECIES VI. PARACUSIS SURDITAS. Deafness. TOTAL INABILITY OF HEARING OR DISTINGUISHING SOUNDS. GEN. II. SPEC. VI. In the preceding species the sense of hearing is in various How differs ways depraved or impaired; in the present it is altogether abolished; and may proceed from causes which offer three distinct varieties of affection: from the preceding species. a P. Sur ditas orga nica. Organic deafness. Causes. Sometimes in the outer entrance. Sometimes The ORGANIC DEFECT or impediment may exist in the outer or inner entrance or in the cavity of the ear. The outer entrance has in a few instances been imperforate *; but far more generally illined and blocked up with indurated wax, excrescences, concretions, or some other substance. The inner entrance or Eustachian tube has been sometimes also found imperforate on both sides, but more in the inner frequently obliterated by ulceration +, or closed by the mucous secretion of a catarrh, or the pressure of the tonsils in whatever way morbidly enlarged. If the defect or impediment exist in the cavity of the ear, its precise nature can seldom be known during the life of the patient, and if known would rarely admit of a remedy. It often consists of a malformation of the helix; and, as we have already seen under PAROTITIS, in a loss of the articulation or substance of one or more of the tympanal bones. or Eusta chian tube. * Cels. De Medicin. Lib. VII. c. 8. Büchner, Miscell. Phys.-Med. P. + Haller. Elem. Phys. Tom. v. p. 286. 318. GEN. II. SPEC. VI. ATONIC DEAFNESS, or that dependent on local debility B P. Sur Atonic deafness. of the ear. or relaxation, may be superinduced by a chronic cold, abruptly plunging the head into cold water in a heated ditas atonica. state, a long exposure to loud and deafening noises, or the sudden and unexpected burst of some vehement sound Causes. upon the ears*, as that of a cannon or a thunder-clap †, Sometimes where the constitution is in a state of great nervous irri- in the cavity tability: in which state moreover it has in a few instances been produced by a violent fright. It has also proceeded from an atony of the excretories of the outer ear, in consequence of which there has been neither wax nor moisture of any kind. And it has followed as a sequel upon various fevers and inflammations, especially cephalitis and otitis, rheumatic hemicrania, and other nervous head-aches, repelled gout, and repelled cutaneous erup tions. ditas pare deafness. Causes PARETIC DEAFNESS may be regarded in many cases as y P. Surnothing more than an extreme of atonic deafness; and tica. almost all the causes producing the one, when operating Paretic with greater violence or upon a feebler frame, may also produce the other. It has not only been induced sud- those of the denly by loud sounds, and violent frights, but by a vehe- preceding ment fit of sneezing, and, from sympathy, by the use of powerful sternutatories §; the olfactory nerve hereby becoming insentient through all its branches. variety. hereditary. Deafness has often been transmitted hereditarily; of Sometimes which numerous and unequivocal instances are to be found in Hoffman ||, Morgagni¶, and other writers of established reputation. medicable. The most usual causes of total deafness are beyond the Often impower of the medical art to relieve; and hence the disease runs very generally through the whole period of life. Where the cause is an imperforation of either of the passages, an opening has been often effected with success. SPEC. VI. tas paretica. Paretic deafness. when ca pable of palliation. of the mas GEN. II. Many other impediments, as of indurated wax, or inP. Surdi- farction from inflammation, are in general removeable still more easily; and some obstructions have been suddenly carried off by a fall or other violent concussion of the Treatment head. The great difficulty, however, is in getting at such impediments when they are formed in the tympanal cavity. The perforation of the mastoid process, recommended by Perforation Riolanus, has been practised occasionally with success, toid process, and especially by the Swedish anatomists Jasser and Puncture of Hagstrom. But the difficulties are so considerable that the plan has usually been superseded by a puncture of the Injection of membrane, or by injecting the Eustachian tube, as first proposed by an unprofessional artist, Guyot of Versailles, and since followed up successively by Cleland, Petit, Douglas, and Wathen. Of late, however, even this has been dropt; though now once more revived in France by M. Itard*, and in great Britain by Mr. Buchanan†. the mem brane. the Eusta chian tube. Stimulants and tonics. Fumes of tobacco sniffed up the Eustachian tube. In deafness from atonic relaxation almost all the stimulant and tonic methods pointed out under the preceding species have been tried in turn, occasionally with palliative success, sometimes altogether in vain. The fumes of tobacco sniffed up the Eustachian tubes from the mouth, in the manner described under the last species were recommended by Morgagnit, and many other writers of earlier times, and have occasionally been found beneficial Obstruction in our own day; the spasm or other obstruction of the fine tubes ceasing of a sudden, and with the sensation of a smart snap that almost startles the patient. And as sight has sometimes been restored in amaurosis by a violent fever, or a flash of lightning, so has deafness from atony, approaching to paralysis, been recovered by a like fever or a thunder clap§; ordinary causes being thus transferred into extraordinary modes of cure. in these tubes has nomena which often become causes. Mode of treatment. Among the stimulants most useful, where the deafness * Ut suprà. + Engraved Representation of the Anatomy of the Human Ear, &c. Hull, 1823. Epist. Anat. vII. Art. 14. Eph. Nat. Cur. Dec. 1. Ann. vi. Obs. 110. § Bresl. Samml. 1718. p. 1541. a SPEC. VI. Deafness. Blisters. Solution of nitrate of Chronic is dependent upon debility of the membrane of the tym- GEN. II. panum, or the nerve of hearing, have been the aura of Paracusis voltaic electricity, applied two or three times a-day for Surditas. half an hour or longer each time, and persevered in for Treatment. many weeks; a series of blisters continued for a long Voltaic period, and a diluted solution of nitrate of silver. Yet electricity. chronic ulcer forming in the ear, and discharging plentifully, has often proved more effectual than any of these. Mr. Gordon, in the Edinburgh Medical Commentaries, silver. relates a case of total deafness produced suddenly on a soldier in good health, by plunging overhead into the sea: which, after a long routine of medicines had been tried in vain for three months, yielded to the use of mercury as soon as the mouth began to be affected. A gentle saliva- Case of cure tion supervened, his hearing was gradually restored, and on in six weeks from its commencement he returned to his duty perfectly cured *. The excitement of the salivary glands seems, in this case, to have extended by sympathy Explained. to the Eustachian tubes, or whatever other parts of the organ of hearing were diseased. ulcer. tion. Puncture of brana tym the mem pani a sub stitute in Eustachian When the Eustachian tubes are imperforate or irrecoverably closed, which may commonly be determined by an absence of that sense of swelling in the ears which otherwise takes place on blowing the nose violently, Rio- imperforalamus, and afterwards Chisselden, proposed a substitute tion of the for the canal by making a small perforation through the tube. membrane of the tympanum; and Sir Astley Cooper has boldly put their recommendation to the test. The artificial opening does not destroy the elasticity of the membrane, and it has hence been occasionally attended with success; and perhaps would be always, if it were to be Its proper limited, as M. Itard + has shown it ought to be, to a permanent obstruction of the Eustachian tube, unaccompanied with inflammation, or any other cause of deafness. And it is from a wanton application of this remedy to as opposed other cases, that it has so often been tried in vain since and wanton Sir Astley Cooper's successful sanction. Edin. Med. Com. Vol. 1. p. 80. + Traité de Maladies de l'Oreilles et de l'Audition, &c. 2 Tomes. Paris, 1821. VOL. IV. limitation, to a useless employ ment. derivation. GENUS III. PAROS MIS. Morbid Smell. SENSE OF SMELL VITIATED OR LOST. GEN. III. THIS is the parosmia and anosmia of many writers; from Synonyms and generic Tapà, "malè", and "gw, "olfacio", analogous with PARAπαρὰ, CUSIS and PAROPSIS: anosmia, however, will not include one of its species, and the present termination is preferred on account of its analogy with that of the parallel terms. Under this genus may be arranged the three following species: SPEC. I. Physiology. SPECIES I. PAROSMIS ACRIS. Acrid Smell. SMELL PAINFULLY ACUTE OR SENSIBLE TO ODOURS NOT GEN. III. GENERALLY speaking, the sense of smell in all animals is in proportion to the extent of the Schneiderian or olfactory membrane with which the nostrils are lined, and over which the branches of the olfactory nerves divaricate and ramify. And hence this membrane is much more ex |