covered till an advanced period of childhood, and though the child remains mute the real cause is neither readily acknowledged nor properly attended to. Children Avho have lost their hearing after the acquisition of the power of speech cannot be included in the class of deaf mutes ; the impression which language has made on their minds gives to them a marked superiority over those who are deaf from birth. Such a calamity as the deprivation of hearing must be productive of great and varied disadvantages, as it totally excludes the mind from an extensive class of ideas and associations. It is then not to be wondered at that this state of social isolation should occasionally give rise to moroseness and despondency, and that external objects should inspire little sense of surprise or admiration. They are simply objects recognized by their form, colour, and texture, and the emotions they raise are different both in character and in intensity from those experienced by hear ing children. This physical defect has not, however, any necessary connection with the presence or absence of intel lectual capacity, or with the active principles of our nature. There is only tlie want of one of the natural and most im portant avenues to intellectual development, with its primary consequence of dumbness, and its secondary one of social isolation. Still, the denial of all such knowledge as can be derived through the medium of the ear is somewhat atoned for by the quickened influence of other senses, especially that of sight. Thus the visible marks of attention the deaf and dumb receive from others, their caresses, frowns, and smiles, all make a corresponding impression on their tender minds, and as they grow older they watch the looks and gestures of those near them with a keenness unknown to other children, so that the slightest change of expression does not escape their observation. Their affections are stimulated and their passions excited much in the same way as in other children. The proportion of children born deaf was formerly sup posed to be much smaller than it really is. Cases have come to be known in largely increased numbers since institutions for the deaf and dumb have been estab lished, and such statistical tables as are given in this article suggest the incorrectness of the popular supposition. The institutions which have been founded on their behalf have not only diffused correct information concerning their number, but by the gratifying success of the educational methods adopted have greatly contributed to dissipate pre judicial notions concerning their capacity to receive instruc tion, and to direct public sympathy towards the claims of this class. The latter office it is still needful that they fulfil, for prejudices yet exist against deaf mutes, one of these being the general supposition that they are very vicious and hot-ternpered. It may be admitted that some of them are so ; and it may even be granted that the pro portion of mutes with such dispositions is as high as in any other class of afflicted persons, for in the case of the deaf and dumb there are undoubtedly special circumstances of early life which tend in no small degree to such a result. The total inability of parents to deal with their abnormal peculiarities must be included among the causes which pre judicially affect their dispositions, and overshadow attractive features of their character ; and the kindly-intended in- terferezice of neighbours with the parental management often proves morally injurious to them. Their discernment of right and wrong is equal to that of other children ; and hence, when neighbours unwisely seek to screen them from merited punishment, a spirit of insubordination is excited, and sullenness or passionateness is induced. It should therefore be the parents utmost endeavour, when punish ment is to be administered, to treat these children im partially. It is most desirable also that external circum stances should be as favourable to them as possible, and everything calculated to pollute their uncultivated minds kept from their acute powers of observation. Causes. The causes assigned for congenital deafness are consanguineous marriages, hereditary transmission, weak constitutions of parents, scrofula, climate, and the ill-health of the mother at a certain period of life. There is necessarily difficulty in ascertaining the real cause of deaf ness. That difficulty has its ground in the unwillingness of parents to admit that their children -were born deaf. Their deafness is often attributed to some infantile disease, though the defect is congenital. On the other hand, when they have lost the sense of hearing at an early age, they may be included among the congenitally deaf. But all institutions for the deaf and dumb contain instances which illustrate scientific investigations, and establish the position that such causes as those now alluded to tend to induce and perpetuate the disease of deafness. In all cases of congenital deafness it will be found that there exists some disorganization of the organ of hearing itself, some obstruc tion in the internal ear or compression of the auditory nerve, whereby the vibrations of the ear are prevented from pro ducing the required effect upon the internal parts of the ear, or from being communicated to the brain. After-birth or acquired deafness occurs at all ages, and has its origin in such diseases as small-pox, measles, typhus, convulsions, paralysis, hydrocephalus, and other affections of the brain, and " scarlatina, which more frequently than any other disease leaves the patient deaf, in consequence of the inflammatory state of the throat extending to the internal ear, causing suppuration and destruction of the delicate apparatus on which hearing depends ; such being the case, especial attention should be directed during the course of the disease to the state of the throat, so as to prevent if possible the inflammation extending." Vaccina tion has been the means of greatly decreasing the cases of deafness; and doubtless, as sanitary laws become more general, the introduction of perfect sewerage, pure water, and good ventilation, will all tend to lessen the liability to those zymotic diseases upon which deafness supervenes. Amongst other causes of deafness are cold, and severe blows or falls upon the head. It has been ascertained that the proportion is about 60 per cent, congenitally deaf to 40 per cent, accidentally so ; and the census returns for 1871 show that of the 1054 inmates of 12 institutions of England and Wales 63 per cent, were congenitally deaf. Consanguineous marriages are perhaps the most fertile source of deafness, which fact is established by the numerous cases of deaf children who are the offspring of first cousins. It is not only so in England, but in other countries of Europe and in America. Dr Buxton says, " In an inquiry which I made some time ago, I found that about every tenth case of deafness resulted from the marriage of cousins." The Irish Commissioners Report for 1871 says, "Too close consanguinity in the intermarriage of relatives, and aUo hereditary predisposition, have long been supposed to be causes of congenital deaf-muteism." The results obtained by the census of 1871 tend to establish these suppositions. The following table from census returns for Ireland exhibits the amount of deaf-muteism where consanguinity of parents existed:— Congenital Deaf Cases. Acquired Deaf Cases. Total. First cousins 80 5 85 Second cousins 60 3 63 Third cousins 31 1 32 Fourth cousins. 7
7 Fifth and sixth cousins. . . 14
14 192 9 201
