The Deaf | Page 8

it not be well to inquire whether or
not deafness may be eliminated, or at least reduced to an appreciable
degree? These are questions that present themselves at the outset in a
consideration of the relation of the deaf to society, and to them we now
devote our attention.
Our first inquiry in the matter is directed to the question whether
deafness as a whole is increasing, decreasing or remaining stationary,
in relation to the general population. To determine this, we have
recourse to the census returns of the deaf in connection with those of
the general population. Unfortunately, however, comparisons of the
different censuses respecting the deaf are not altogether to be depended
upon, for the reason that they have not always been taken on the same
basis, and conclusions from them consequently have to be accepted
with qualifications. Special census returns of the deaf have been made

since 1830; but the censuses of 1830-1870 purport to be of the deaf and
dumb; the census of 1880, of the deaf who became deaf under sixteen
years of age; that of 1890, of the deaf and dumb; that of 1900, of the
totally deaf; and that of 1910, of the deaf and dumb. The results thus
obtained are in the main analogous, but there are a certain number of
cases included on one basis that would be excluded on another, and
vice versa.[15]
Taking the statistics as they are, we have the following table,[16] which
gives the number of the deaf as found in the several censuses,
according to the bases upon which they were made, together with the
ratio per million of population.
NUMBER OF THE DEAF ACCORDING TO THE CENSUSES OF
1830-1910
NO. PER MILLION OF YEAR NUMBER POPULATION
1830 (the deaf and dumb) 6,106 475 1840 (the deaf and dumb) 7,665
449 1850 (the deaf and dumb) 9,803 423 1860 (the deaf and dumb)
12,821 408 1870 (the deaf and dumb) 16,205 420 1880 (deafness
occurring under sixteen) 33,878 675 1890 (the deaf and dumb) 40,592
648 1900 (the totally deaf) 37,426 492 1910 (the deaf and dumb)
43,812 476
From this table there appears to be a steady decrease in the number of
the deaf in relation to the general population from 1830 to 1860, this
latter year seeming to be the low water mark. From 1860 to 1870 there
is a slight increase, and from 1870 to 1880 a very large one, due to
some extent to the method of taking the census. From 1880 to 1890
there is a certain decrease, though the proportion is still very high.
From 1890 to 1900 there is a very considerable decrease, probably
indicating a return to true conditions; and a not negligible decrease
from 1900 to 1910.
On the whole, with respect to these statistics, probably the most that we
can safely say is that deafness is at least not on the increase relatively
among the population, while there is a possibility that at present it is

decreasing. For further determinations, we shall have to seek other
means of inquiry.
THE ADVENTITIOUSLY DEAF AND THE CONGENITALLY
DEAF
We may perhaps best approach the problem of deafness as an
increasing or decreasing phenomenon in the population, if we think of
the deaf as composed of two great classes: those adventitiously deaf,
that is, those who have lost their hearing by some disease or accident
occurring after birth, and those congenitally deaf, that is, those who
have never had hearing.[17] In regard to the former class, it follows
that we are largely interested in the consideration of those diseases,
especially those of childhood, which may affect the hearing, and in
their prevention or diminution we can endeavor to ascertain how far
there are possibilities of reducing the number of the deaf of this class.
In the latter case we are called upon to examine some of the great
problems involved in the study of heredity, especially in respect to the
extent that the offspring is affected by defects or abnormalities of the
parent, and to see what, if any, means are at hand to alter conditions
that bring about this form of deafness. We shall first discuss the causes
of adventitious deafness, together with the possibilities of its prevention
and the likelihood of its diminution, and then consider the questions
involved in congenital deafness.
ADVENTITIOUS DEAFNESS AND ITS CAUSES
From three-fifths to two-thirds of the cases of deafness are caused
adventitiously--by accident or disease. To accidents, however, only a
very small part are due, probably less than one-fiftieth of the entire
number.[18] Nearly all adventitious deafness results from some disease,
either as a primary disease of the auditory organs, or as a sequence or
product of some disease of the system, often one of infectious character,
the deafness thus constituting a