Causes Of Deaf-mutism


The intermarriage of blood-relations is doubtless one cause. In one

school for the deaf and dumb 25 per cent., in another 20 per cent., and

in others 15 per cent. of the pupils are said to be the off-spring of

marriages between blood-relations.



Davy mentions the following case observed by Meniere:--A married couple,

being cousins, who enjoyed excellent health, had eight children, of whom

four were born de
f mutes, another was idiotic, another died when five

years of age, and two others suffered from absolute deafness, which only

made its appearance later on.



In the Institution at Derby there are three sisters, and also a younger

sister at home, all born deaf and dumb, the parents being own cousins.

On the other hand, there are at the same Institution several children

having deaf and dumb brothers or sisters, where no relationship exists

between the parents, notably one family, in which both parents are

healthy, and in which there are four deaf and dumb children. In the same

county there are other cases of three, four, and even six in a family,

yet there has been no relationship between the parents. In addition to

the born deaf, measles, bronchitis, typhus, scarletina, and other

diseases are the causes of deafness, and consequently dumbness.



Cases are known to have resulted from lightning, fright, boxing on the

ears, and where young children have been allowed to fall on the head,

etc.



Damp houses are said to be a cause of deafness. In Paris among eight

children born in a family, five were born deaf, and these had all been

born in a damp house. The family who had previously lived in the same

house had three children, among whom were two born deaf and dumb. It is

sometimes said that certain unhealthy trades in which the parent or

parents are engaged are responsible for some of these cases, but the

only complete statistics are those of Nassau, the results of which are

as follows:--



Among 27 Pipe-makers 3 deaf mute children,

therefore 1 deaf mute to 9.0

" 146 Stonemasons 4 " " " 36.5

" 186 Brass-founders 5 " " " 37.2

" 106 Potters 2 " " " 53.0

" 590 Carpenters 8 " " " 73.7

" 176 Earthenware-makers 2 " " " 88.0

" 381 Sailors 3 " " " 127.0

" 1,716 Bricklayers 11 " " " 156.0

" 1,309 Smiths 7 " " " 187.0

" 374 Vat-coopers 2 " " " 187.0

" 1,894 Tailors 10 " " " 189.4

" 2,911 Shoemakers 15 " " " 194.0

" 1,614 Joiners 8 " " " 201.7

" 2,006 Vinters 9 " " " 222.8

" 514 Coopers 2 " " " 257.0

" 1,380 Bakers 5 " " " 276.0

" 49,201 Farmers 104 " " " 473.1

" 18,211 Labourers 24 " " " 758.8



Meckel says that in the families of tradespeople, who are constantly

exposed to a damp unhealthy atmosphere or other injurious influences,

deaf-mutism occurs most frequently. Moreover, Meckel has found that

deaf-mutism is more frequently met with in flour-mills than elsewhere.

Among 990 millers in Nassau, there were found eight deaf mutes, or one

deaf mute to 123.7.



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