SUMMARY._Encyclopaedia Britannica, 11th Edition, "David, St" to "Demidov" Volume 7, Slice 10

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|Africa | 7 | 16 | 127 |

|Asia | 9 | 47 | 453 |

|Australia | 7 | 46 | 332 |

|Europe | 450 | 3152 | 25,886 |

|North America | 135 | 1490 | 11,760 |

|South America | 7 | 34 | 229 |

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| | 615 | 4785 | 38,787 |

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These figures refer only to deaf children who are actually under

instruction, not to the whole deaf population.

While it is gratifying to find that so much is being done in the way

of educating this class of the community, the number of schools in

most parts of the world is still lamentably inadequate. For instance,

taking the school age as from seven to sixteen, which is now made

compulsory by Act of Parliament in Great Britain, and assuming that

20% of the deaf population are of that age, as they are in England,

there should be 40,000 deaf pupils under instruction in India alone,

whereas there are but seventy-three. There are 200,000 deaf of all

ages in India. And what an enormous total should be in schools in

China instead of forty-three! The whole of the rest of Asia, with the

exception of Japan, has apparently not a single school. There must be

many thousands of thousands of deaf (hundreds of thousands, if not

thousands of thousands of whom are of school age) in that continent,

unless indeed they are destroyed, which is not impossible. What are we

to say of Africa, where only 100 pupils are being taught; of South

America, with its paltry 200, and Australia's 300? To come to Europe

itself, Russia should have many times more pupils than her 1700. Even

in Great Britain the education of the deaf was not made compulsory

till 1893, and there are many still evading the law and growing up

uneducated. Mr Payne of Swansea estimated (_Institution Report_,

1903-1904) from the 1901 census, that there must be approximately 204

deaf of school age in South Wales and Monmouthshire, while only 144

were accounted for in all the schools in that district according to Dr

Hitz's statistics.

Dr Kerr Love (_Deaf Mutism_, p. 217) gives the following table, which

shows the number of deaf people in proportion to the population in the

countries named:--

Switzerland 1 in 408

Austria " 765

Hungary " 792

Sweden " 977

Prussia " 981

Finland " 981

Canada " 1003

Norway " 1052

Germany (exclusive of Prussia) " 1074

Portugal " 1333

Ireland " 1398*

India " 1459

United States " 1514

Denmark " 1538

Greece " 1548

France " 1600

Italy " 1862

Scotland " 1885*

Cape Colony " 1904

England " 2043*

Spain " 2178

Belgium " 2247

Australasia " 2692

Holland " 2985

Ceylon " 4328

* The figures for England, Scotland and Ireland, according to the

1901 census, are different and have been given above.

According to a tabular statement of British and Colonial schools, June

1899, the proportion of those born deaf to those who lost hearing

after birth was, at that time and in those countries, 2126 to 1251, as

far as returns had been made. Several schools had, however, failed to

give statistics. These figures show a proportion of nearly 59%

congenitally deaf persons to over 41% whose deafness is acquired.

Professor Fay, whose monumental work, _Marriages of the Deaf in

America_, deserves particular attention, mentions (p. 38) that of

23,931 persons who attended American schools for the deaf up to the

year 1890, 9842, or 41%, were reported as congenitally deaf, and

14,089, or 59%, as adventitiously deaf,--figures which exactly reverse

those just quoted. The classification of deafness acquired in infancy

with congenital deafness by some other authorities (giving rise to the

rather absurd term "toto-congenital" to describe the latter) is

unscientific. There is reason for the opinion that the non-congenital,

even when hearing has been lost in early infancy, acquire language

better, and it is a mistake from any point of view to include them in

the born deaf.

Other statistics vary very much as to the proportion of born deaf,

some being as low as a quarter, and some as high as three-quarters, of

the whole class. We can only say, speaking of both sides of the

Atlantic, and counterbalancing one period with another, that the

general average appears to be about 50% for each. Probably the

percentage varies in different places for definite reasons, which we

shall now briefly consider.

_Causes of Deafness._--These may be considered in two divisions,

pre-natal and post-natal.

1. _Pre-Natal._--A small percentage of these is due, it seems, to

malformation of some portion of the auditory apparatus. Another

percentage is known to represent the children of the intermarriage of

blood relations. Dr Kerr Love (_Deaf Mutism_, p. 117) gives statistics

from thirteen British institutions which show that on a general average

at least 8% of the congenitally deaf are the offspring of such

marriages. Besides this, little is known. Beyond all doubt a much larger

percentage of deaf children are the offspring of marriages in which one

or both partners were born deaf than of ordinary marriages. But

inquiries into such phenomena have generally been directed towards

tracing deafness and not consanguinity, or at least the inquirer has

rarely troubled to make sure whether the grandparents or

great-grandparents on either side were relations or not. Such

investigations rarely go beyond ascertaining if the parents were related

to each other, though we have proof that a certain tendency towards any

particular abnormality may not exhibit itself in every generation of the

family in question. To give an illustration, suppose that G is a deaf

man. Several inquirers may trace back to the preceding generation F, and

to the grandparents E, and even to the great-grandparents D, in search

of an ancestor who is deaf, and such they may discover in the third

generation D. But probably not one of these several inquirers will ask G

if any of his grandparents or great-grandparents married a cousin, for

instance, though they may ask if his father did. To continue this

hypothetical case, the investigators will again trace back along the

family tree to generations C, B and A in search of an original _deaf_

ancestor, on whose shoulders they seek to lay the blame of both D's and

G's deafness. Not finding any such, they will again content themselves

with asking if D's parents (generation C) were blood relations or not,

and, receiving an answer in the negative, desist from further inquiry in

this direction, assuming that D's deafness is the original cause of G's

deafness. They do not, we fear, inquire if any grandparents or

great-grandparents (hearing people) were related, with the same

persistency as they ask if any were deaf. The search for deafness is

pushed through several generations, the search for consanguinity is only

extended to one generation. Perhaps if it were carried further, it would

be discovered that A married his niece, and there lay the secret of the

deafness in both D and G. In other words, the deafness in D is not the

cause of that in G, but the deafness in both D and G are effects of the

consanguineous marriage in A. All this is, however, merely by way of

suggestion. We submit that if deafness in one generation may be followed

by deafness two or even three generations later, while the tendency to

deafness exists, but does not appear, in the intermediate generations,

it is only logical to inquire if deafness in the first discoverable

instance in a family may not be caused by consanguinity, the effect of

which is not seen for two or three generations in a similar manner.

Moreover it is probable that consanguinity in parents or grandparents

may often be denied. An exhaustive investigation along these lines is

desirable, for we believe that congenital deafness would be proved to be

due to consanguinity in hearing people, if the search were pushed far

enough back and the truth were told, in a far greater percentage of

cases than is now suspected. This is not disproved by quoting numbers of

cases where no deafness follows consanguinity in any generation, for

resulting weakness may be shown (where it exists) in many other ways

than by deafness.

This theory receives support from the statistics quoted by Dr Kerr Love

(_Deaf Mutism_, p. 132), where the percentage of defective children

resulting from the consanguineous marriages of hearing people increases

in almost exact proportion to the nearness of affinity of the parents.

It is further borne out by statistics of the duchy of Nassau, and of

Berlin, both quoted by Dr Kerr Love (pp. 119, 120). These show 1 deaf

person in 1397 Roman Catholics, 1101 Evangelicals and 508 Jews in the

former case, and 1 in 3000 Roman Catholics, 2000 Protestants and 400

Jews in the latter. When we are told that "Roman Catholics prohibit

marriages between persons who are near blood relations, Protestants view

such marriages as permissible, and Jews encourage intermarriage with

blood relations," these figures become suggestive. We find the same

greater tendency to deafness in thinly-populated and out-of-the-way

districts and countries where, owing to the circle of acquaintances

being limited, people are more likely to marry relations.

With regard to the question of marriages of the deaf, Professor Edward

Allen Fay's work is so complete that the results of his six years'

labour are particularly worthy of notice, for, as the introduction

states, the book is a "collection of records of marriages of the deaf

far larger than all previous collections put together," and it deals

in detail with 4471 such marriages. The summary of statistics is as

follows (_Marriages of the Deaf in America_, p. 134):--

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| MARRIAGES +------+----------+------+-----+----------+---------+

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| deaf | 3078 | 300 | 6782 | 588 | 9.7 | 8.6 |

| Both partners deaf | 2377 | 220 | 5072 | 429 | 9.2 | 8.4 |

| the other hearing | 599 | 75 | 1532 | 151 | 12.5 | 9.8 |

| congenitally deaf, | 1477 | 194 | 3401 | 413 | 13.1 | 12.1 |

| adventitiously deaf | 2212 | 124 | 4701 | 199 | 5.6 | 4.2 |

| congenitally deaf | 335 | 83 | 779 | 202 | 24.7 | 25.9 |

| adventitiously deaf | 814 | 66 | 1820 | 119 | 8.1 | 6.5 |

| adventitiously deaf | 845 | 30 | 1720 | 40 | 3.5 | 2.3 |

| the other hearing | 191 | 28 | 528 | 63 | 14.6 | 11.9 |

| the other hearing | 310 | 10 | 713 | 16 | 3.2 | 2.2 |

| deaf relatives | 437 | 103 | 1060 | 222 | 23.5 | 20.9 |

| had not | 541 | 36 | 1210 | 78 | 6.6 | 6.4 |

| deaf relatives | 471 | 11 | 1044 | 13 | 2.3 | 1.2 |

| relatives | 172 | 49 | 429 | 130 | 28.4 | 30.3 |

| had not | 49 | 8 | 105 | 21 | 16.3 | 20.0 |

| relatives | 14 | 1 | 24 | 1 | 7.1 | 4.1 |

| relatives. | 57 | 10 | 114 | 11 | 17.5 | 9.6 |

| had not | 167 | 7 | 357 | 10 | 4.1 | 2.8 |

| relatives | 284 | 2 | 550 | 2 | 0.7 | 0.3 |

| consanguineous | 31 | 14 | 100 | 30 | 45.1 | 30.0 |

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One point deserves special attention in the above list. It is that

where there are no deaf relatives (i.e. where there has not been a

history of deafness in the family) only one child out of twenty-four

is deaf, even when the parents were both born deaf themselves. Where

there were deaf relatives already in the family on both sides, and the

parents were born deaf, the percentage of deaf children is seven and a

half times as great. This seems to show that there are causes of

congenital deafness which are, comparatively speaking, unlikely to be

transmitted to future generations, while other causes of congenital

deafness are so liable to be perpetuated that one child in every three

is deaf. We conjecture that one original cause of congenital deafness

which reappears in a family is consanguinity--for instance, the

intermarriage of first or second cousins (hearing people) in some

previous generation. Out of the 2245 deaf persons who were born deaf,

269 had parents who were blood relations, according to Fay. And

perhaps many more refrained from acknowledging the fact. Eleven had

grandparents who were cousins. This theory calls for investigation,

and while the marriage of deaf people is not encouraged, it is fair to

ask those who so strenuously oppose such unions whether they may not

be spending their energies on trying to check an effect instead of a

cause, and if that cause may not really be consanguinity,--witness the

percentage of deaf people among Roman Catholics, Protestants and Jews

before noticed. On the principle that prevention is better than cure

it is the intermarriage of cousins and other relations which should be

discouraged. The marriage of deaf people is inadvisable where there

has been deafness in the family in former generations, but the same

warning applies to all the other members of that family, for the

hearing members are as likely to transmit the defect of which deafness

is a symptom as the deaf members are. We are more concerned to

discover the primary cause of the defect, and take steps to prevent

the latter from occurring at all. Those who have no dissuasions for

hearing people, who might perhaps cause the misery, and only give

counsel to those among the transmitters of it who happen to be deaf,

are acting in a manner which is hardly logical.

2. _Post-Natal._--We have collected and grouped the stated causes of

deafness in those partners of the marriages in America noticed by Fay.

About a hundred and thirty did not mention how they lost hearing. Any

errors in this calculation must be less than 1% at most, and can make no

material difference. In some cases two or more diseases are given as the

cause of deafness. In such cases where one is a very common cause of

deafness, and the other is unusual, the former is credited with being

the reason for the defect. Where both are common, we have divided the

cases between them in a rough proportion.

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