Page:The American Cyclopædia (1879) Volume V.djvu/733

 DEAF AND DUMB T29 The numbers for England, the only ones yet received from the census of 1871, were kindly furnished by the registrar general through Dr. Buxton of Liverpool, in advance of publi- cation, and are liable to slight changes. The decrease in 10 years, on the whole, and in every district but three, is remarkable; it amounts to 6*23 per cent., while the total population increased 13-15 per cent. NUMBEB OF THE DEAF AND DUMB IN GEEAT BRITAIN AND IRELAND. DISTRICTS. 1851. 1861. 1871. England and Wales. 1325 1 819 1733 II. Southeastern 836 1,022 965 III. S. Midland 649 789 672 IV Eastern 669 729 635 V. Southwestern 1,295 1321 1,097 VI. W. Midland 1 825 1 613 1466 VII N Midland 694 748 682 VIII. Northwestern IX. Yorkshire 1,237 1 042 1,582 1222 1,677 1226 X Northern 471 577 626 XI. Wales and Monmouthshire 771 814 739 Total England and Wales.. . . Scotland. . 10,314 2155 12,236 2335 11,518 ) returns 4,747 4,930 Isles in British seas 84 87 receiv'd Grand total 17,800 19,638 In Europe congenital cases preponderate, in America adventitious cases, as is shown in the following comparison : Congenital. Adventitious. Unknown. Total. 4 British institutions. . 8,283 912 .... 4,200 7 American u . . 1,401 1,983 400 8,784 The following table shows the ages at which deafness occurred in 2,472 cases in the United States, and in 1,458 cases in Europe : AGE. United States. Europe. Under 1 year 485 140 680 835 2 and 8 443 295 8 and 4 229 226 4 and 5 5 and 6 196 137 125 87 6 and 7 98 91 7 and 8 79 87 8 and 9 . ... 82 20 9 and 10 22 21 10 and 15 41 50 15 and 21 7 12 Total... 2,472 1,453 Causes of Deafness. The causes of deafness are both ante-natal and post-natal. Ante-natal causes produce not merely congenital deafness, but also gradual decay of hearing, or a weak- ness in the organ predisposing it to yield to a slight attack. The most obvious and in- contestable of these are the consanguinity of parents and hereditary transmission. Dr. Bemiss of Louisville, Ky., on investigating 833 consanguineous marriages, found that of the 3,942 offspring 1,134 were defective, of whom 145 were deaf and dumb ; and estimated that 10 per cent, of the deaf in the United States sprang from kindred parents. Dr. Bux- ton of Liverpool found the same percentage in Great Britain, and met with as many as eight deaf children from such a union. The prevalence of deafness as well as of idiocy, cretinism, and goitre, in mountainous districts (the deaf amounting at one time to 1 per cent, of the total population in part of the canton of Vaud, Switzerland), must be partly due to the intermarriages in a secluded and stationary population; and the less proportion of con- genital to adventitious cr.ses in the United States than in Europe, to the free intermixture of races here. Hereditary transmission is less common than is often believed. According to the computations of Dr. H. P. Peet of New- York, the probability of deafness occurring in the offspring of parents who are deaf from adventitious causes is 1 in 1,600, or in the same proportion as when both parents are hearing ; but when one parent is congenitally deaf, the chances in the offspring are as 1 to 130; and when both parents are congenitally deaf, the chances are that 1 in 10 of the offspring will be deaf. Influences acting on the imagi- nation of the mother are often assigned as causes of deafness ; but inquiry seldom fails to reveal other and adequate ones. Congenital deafness occurs among all ranks and nationali- ties. The most prominent post-natal causes are scarlet fever, scrofulous and syphilitic af- fections, and spotted fever or cerebro-spinal meningitis. In the United States, scarlet fever has since 1830 been most fruitful, producing 20 to 25 per cent, of the total cases ; spotted fever, after subsiding for a period, has within the past ten years commenced an era of fresh viru- lence, especially in the western states ; scrofu- lous traces have been observed in from 30 to 75 per cent, of the inmates of various institu- tions. Added to these causes from disease are those produced by mechanical injury. The following table is compiled from the statistics of the New York, Pennsylvania, Kentucky, Ohio, Virginia, Indiana, Illinois, and Minnesota institutions, generally embracing the whole period of their existence : CAUSES OF DEAFNESS. I. Affections acting locally on the organ of hearing. Scarlet fever 460 Measles 92 Smallpox 4 Other exanthemata 18 Diseases of the ear 10 Diseases of the throat and lungs 83 Scrofula and rickets 82 Glandular diseases Ill 765 II. Affections acting on the brain and nervous system. Brain fever, inflammation, and congestion 219 Spinal and nervous dis- eases 21 Fright and convulsions. . 48 Whooping cough 56 Teething 14 Dropsy of the brain 25 149 Fever, spotted Fever, typhus and ty- phoid 82 Fever, intermittent 82 Fever, bilious and gastric 15 Fever, yellow 1 Fever, not specified 116 Falls 86 Quinine and mercury 16 III. Doubtful. Colds and rheumatism. .. 89 Cholera, dysentery, &c. . . 15 Various diseases 27 Various accidents 57 Sickness or accident not specified 198 Gradual decay 2 Total. .1,983