CAUSES OF ADVENTITIOUS DEAFNESS IN 1880, 1890 AND 1900
| 1880 | 1890 | 1900 | |
| Scarlet fever | 7.9 | 11.8 | 11.1 |
| Meningitis | 8.4 | 7.8 | 9.6 |
| Catarrh and catarrhal fevers | 0.9 | 3.3 | 3.6[33] |
| Diphtheria | 0.2 | 0.5 | —[34] |
| Abscess and inflammation | 1.0 | 2.5 | —[35] |
| Measles | 1.3 | 2.5 | 2.5 |
| Whooping cough | 0.5 | 0.8 | —[34] |
| Malarial and typhoid fevers | 1.7 | 1.8 | 3.6 |
| Other fevers | 1.1 | — | 2.0 |
In this table the most noticeable thing is perhaps the persistency with which we find most of the diseases to recur, with apparently no great change, while in certain ones, as catarrh and malarial and typhoid fevers, there seems to be rather an increase. It would be best, however, not to place very great confidence in these figures, but, so far as the census reports are concerned, to wait for more precise and uniform statistics.
We have, further, the statistics published in the reports of certain schools for the deaf. While these are perhaps not of sufficient extent to warrant full conclusions, they may be regarded as quite representative;[36] and though to be taken with something of the caution as the census figures, they may serve to throw some light upon the situation. Comparison of the proportions of pupils deaf from the several diseases at different times may be made in two ways: by finding the respective proportions over a series of successive years from a certain time back down to the present, and by contrasting the proportions in two widely separated periods, one in the present and one in the past. These will be taken up in order.
The following tables give the percentages of cases of deafness in pupils from the important diseases as found in six schools in successive years: in the New York Institution in the total annual attendance from 1899 to 1912; in the Michigan School in the total biennial attendance from 1883 to 1912; in the Pennsylvania Institution in the number of new pupils admitted quadriennially from 1843 to 1912; in the Western Pennsylvania Institution in the number admitted biennially from 1887 to 1912; in the Maryland School in the number admitted biennially from 1884 to 1911; and in the Wisconsin School in the number admitted biennially from 1880 to 1908.
I. CAUSES OF DEAFNESS IN NEW YORK INSTITUTION FROM 1899 TO 1912
| 1899 | 1900 | 1901 | 1902 | 1903 | 1904 | 1905 | 1906 | 1907 | 1908 | 1909 | 1910 | 1911 | 1912 | |
| Total Number | 466 | 476 | 481 | 477 | 464 | 503 | 508 | 510 | 543 | 555 | 565 | 570 | 546 | 518 |
| Congenital | 36.0 | 27.1 | 26.8 | 40.9 | 36.2 | 41.1 | 46.2 | 31.8 | 33.3 | 34.4 | 34.9 | 32.8 | 34.6 | 36.6 |
| Scarlet Fever | 11.4 | 10.1 | 8.9 | 7.1 | 6.5 | 6.9 | 6.5 | 4.9 | 5.3 | 5.0 | 5.7 | 6.1 | 5.7 | 5.0 |
| Meningitis | 9.5 | 9.4 | 7.7 | 7.9 | 7.8 | 7.9 | 11.0 | 12.2 | 16.8 | 18.6 | 17.7 | 17.9 | 19.0 | 19.7 |
| Brain Trouble | 10.1 | 9.2 | 8.3 | 8.1 | 7.2 | 5.9 | 5.9 | 7.1 | 9.0 | 8.3 | 8.7 | 8.3 | 8.0 | 8.9 |
| Falls | 9.0 | 7.2 | 5.4 | 4.5 | 3.9 | 4.2 | 3.8 | 5.2 | 5.9 | 6.1 | 6.0 | 5.1 | 5.5 | 5.6 |
| Measles | 5.1 | 3.8 | 3.8 | 2.1 | 3.9 | 4.5 | 4.1 | 4.1 | 4.8 | 4.7 | 4.4 | 4.6 | 0.2 | 0.7 |
| Typhoid Fever | 3.7 | 2.3 | 1.6 | 1.0 | 0.9 | 1.2 | 1.0 | 1.0 | 1.3 | 1.3 | 1.2 | 1.1 | 0.9 | 0.5 |
| Convulsions | 3.2 | 4.4 | 3.2 | 2.9 | 2.6 | 0.2 | 1.8 | 1.8 | 1.9 | 1.5 | 1.9 | 1.9 | 2.0 | 2.1 |
| Various Fevers | 2.5 | 1.5 | 1.4 | 1.0 | 1.7 | 1.6 | 1.6 | 1.6 | 1.5 | 1.3 | 0.7 | 0.5 | 0.5 | 0.7 |
| Catarrh | 2.3 | 2.1 | 1.9 | 1.8 | 1.6 | 1.2 | 1.0 | 2.0 | 1.9 | 1.9 | 1.4 | 0.8 | 1.0 | 0.5 |
| Diphtheria | 1.9 | 1.7 | 1.9 | 1.0 | 0.9 | 0.4 | 0.6 | 0.8 | 0.9 | 0.9 | 0.7 | 0.7 | 0.7 | 0.5 |
| Pneumonia | 1.5 | 0.8 | 0.8 | 0.6 | 1.1 | 0.2 | 1.0 | 1.1 | 1.1 | 0.9 | 1.1 | 1.1 | 0.7 | 0.5 |
| Whooping Cough | 1.7 | — | 1.6 | 1.2 | 1.1 | 1.0 | 0.8 | 0.6 | 0.9 | 0.9 | 0.5 | 0.5 | 0.5 | 0.2 |
| Miscellaneous and Unknown | 2.1 | 20.4 | 26.7 | 19.8 | 18.6 | 23.7 | 14.7 | 25.9 | 15.4 | 14.2 | 15.1 | 18.6 | 20.7 | 18.5 |
II. CAUSES OF DEAFNESS IN MICHIGAN SCHOOL FROM 1883 TO 1912
| 1883 1884 | 1885 1886 | 1887 1888 | 1889 1890 | 1891 1892 | 1893 1894 | 1895 1896 | 1897 1898 | 1899 1900 | 1901 1902 | 1903 1904 | 1905 1906 | 1907 1908 | 1909 1910 | 1911 1912 | |
| Total Number | 302 | 336 | 342 | 350 | 343 | 365 | 428 | 412 | 441 | 447 | 451 | 404 | 361 | 354 | 353 |
| Congenital | 7.0 | 18.8 | 23.1 | 26.3 | 24.2 | 26.3 | 25.2 | 30.3 | 28.8 | 31.5 | 32.8 | 36.6 | 35.7 | 35.0 | 31.2 |
| Meningitis | 28.8 | 28.1 | 23.1 | 23.1 | 21.3 | 15.8 | 15.6 | 14.5 | 10.2 | 9.2 | 4.6 | 8.6 | 9.5 | 8.8 | 8.2 |
| Scarlet Fever | 12.2 | 11.8 | 12.3 | 11.2 | 9.0 | 9.6 | 9.5 | 9.7 | 9.5 | 9.3 | 7.6 | 6.9 | 5.8 | 3.6 | 4.5 |
| Brain Fever | 6.2 | 6.5 | 4.8 | 3.7 | 5.2 | 6.9 | 6.6 | 6.3 | 5.4 | 3.8 | 3.8 | 2.7 | 2.5 | 2.3 | 1.0 |
| Typhoid Fever | 4.6 | 3.6 | 4.1 | 4.3 | 4.7 | 1.9 | 1.8 | 1.4 | 2.5 | 2.2 | 1.3 | 1.0 | 1.4 | 1.5 | 1.7 |
| Measles | 3.6 | 4.1 | 3.9 | 2.9 | 2.6 | 1.4 | 0.8 | 1.9 | 3.2 | 3.1 | 2.9 | 2.9 | 4.1 | 3.4 | 3.1 |
| Diphtheria | 0.6 | — | — | 0.3 | 0.3 | 0.3 | 0.2 | 0.2 | 0.4 | 0.2 | 0.4 | 0.5 | 0.2 | 0.3 | 0.3 |
| Catarrh | 0.6 | 0.6 | 0.9 | 0.8 | 0.9 | 1.1 | 1.9 | — | 2.9 | 3.5 | 3.3 | 2.8 | 1.9 | 2.5 | 0.8 |
| Various Fevers | 2.9 | 1.5 | 2.0 | 2.6 | 3.0 | 4.4 | 4.4 | 1.7 | 2.9 | 2.9 | 3.3 | 2.5 | 0.5 | 2.0 | 1.4 |
| Whooping Cough | 1.3 | 1.2 | 1.5 | 1.5 | 1.5 | 3.0 | 3.8 | 3.6 | 2.7 | 2.5 | 3.1 | 3.4 | 4.4 | 4.8 | 5.1 |
| Pneumonia | — | — | — | — | — | — | — | — | 0.2 | 0.2 | 0.4 | — | 0.7 | 0.6 | 0.8 |
| La grippe | — | — | — | — | — | — | — | — | 0.9 | 1.1 | 1.6 | 1.5 | 3.0 | 2.3 | — |
| Miscellaneous and Unknown | 32.2 | 23.8 | 24.3 | 23.3 | 27.3 | 29.3 | 30.2 | 30.4 | 30.4 | 31.5 | 34.9 | 30.6 | 30.3 | 32.9 | 41.9 |