to restore the Deaf and Dumh to hearing. 308 



great as to occasion dumbness, was always caused by paralysis of the 

 labyrinthic nerve. Such, in fact, is the negative condition in which 

 the ear and the parts connected with it, present themselves to the eye 

 of the dissector, in the great majority of deaf mutes. Farther and 

 more accurate observation, however, enabled him to discover, in 

 some cases, palpable causes of this defect. He twice found the 

 cavity of the tympanum filled with concretions of a chalky appear- 

 ance, and in two other instances with fungous excrescences, in con- 

 nection with the loss of the membrane of the tympanum and the 

 little bones. A fifth subject presented a mass of gelatinous matter, 

 which filled not only the cavity of the tympanum, but the semi-cir- 

 cular canals of the labyrinth. In another, who died after two years 

 of malignant fever, the auditory nerve had little more consistence 

 than mucus. Others have found the Eustachian tube in some cases 

 filled, and in others completely obliterated. The partial or total 

 imperforation of the meatus auditorius has been observed. Morbid 

 affections of the tympanum of a nature opposed to the transmission 

 of sound have been met with. Other organic defects have been 

 discovered ; but the requisite scientific technicality would render it 

 improper to describe them here. 



The results thus obtained, inform us only of the defects of the 

 organ of hearing, and the manner in which they prevent it from be- 

 coming the vehicle of sound. If we search farther and inquire how 

 these defects arise : the answer is, that in many cases they are con- 

 genital, and in many others are produced by disease or accident after 

 birth. From inquiries instituted by several of the institutions for 

 the deaf and dumb in Europe, and in this country by the American 

 Asylum, it appears that of four hundred and forty five deaf mutes, 

 respecting whom inquiry has been made, two hundred and forty four 

 became deaf after birth, and two hundred and one were born in that 

 condition ; and that the causes to which the loss of hearing was most 

 commonly attributed, were fevers, especially the scarlet fever, epi- 

 leptic fits, convulsions, inflammation of the brain, the small pox and 

 measles, blows on the head, violent falls, etc. Copious details on 

 this subject will be found in the third biennial circular of the Paris 

 Institution.* 



* TroisUme circulaire de VInstitut royal des sourds-muets de Paris, a, toutes 

 les institutio7is de sourds-muets de I' Europe, de I'Avidrique et de VAsie. Paris, 

 1832. 



