Deaf-mutism is, therefore, from an anatomical point of view, in most cases to be considered as a result of an abnor mality of the labyrinth.
Prognosis.—There is no doubt that the prog,nosis of the deafness which is the cause of deaf-mutism is highly unfavor able, still there exist some well-authenti cated cases of deaf-mutes whose power of hearing has been at least partially re stored.
Treatment.—It is as yet difficult to say in what cases treatment is indicated, as we have not reached further than to the first experiments in that direction. I have latterly endeavored to act accord ing to the following rules when deaf mutes have been brought to me for treat ment: Treatment is most decidedly in dicated when the deaf-mute suffers from suppurative inflammatory processes of the middle ear. Treatment can, at least in such cases, remove or diminish the danger which always attaches to sup puration of the midde ear. TIchermann's experience also proves that the defects in the power of hearing may be dimin ished in cases of this nature. Treatment is also, I think, indicated in cases in which there are some traces of the power of hearing, and especially when this power exists with varying intensity, and where there are also symptoms of ca tarrhal conditions in the middle ear (ca tarrhal changes of the membrana tym pani, retraction of the manubrium of the malleus, occlusion of the tubT, etc.); also catarrh of the mucous membranes ad jacent to the ear, especially when there also exist hypertrophy of the adenoid tis sue in the naso-pharyngeal cavity. If the cranio-tympanic conduction still exists, the chances in this group of cases seem more favorable still. In cases of catarrh of the middle ear and adjacent mucous membranes, where no signs of hearing can be discovered after repeated examination, I have also attempted treat ment; though I am not certain that such a course gives any hopes, as my experi ence has not been very favorable in this group of cases.
Useful hearing obtained in a deaf mute aged 19 years. On examining the naso-pharynx a dense band of hyper trophy in each Rosenmiiller fossa was found. The hypertrophied tissue was removed, and her ears were regularly politzerized. This was followed by a very great improvement in hearing, so that words distinctly spoken at the dis tance of a few feet in the ordinary voice could be understood. Gibson (Aus tralasian Med. Gaz., Oct., 1900).
To all the above-mentioned groups the indications are the same, whether the deafness is congenital or acquired. Va rious circumstances, which have been pointed out in the foregoing pages, indi cate that total deafness resulting from acute infectious diseases, especially cere brospinal meningitis and scarlet fever, and accompanied by slight catarrhal changes, is due to a constant labyrinth ine disease which defies all treatment.
So far as the nature of an ultimate treatment is concerned, it must be ob served that general and special otological principles must be used as guides, and the treatment, in the majority of cases, should be local.
Treatment in other than the above mentioned cases of deaf-mutism is, of course, justified when it is not accom panied by any danger to the patient, when it is indicated. by otological princi ples, and when it is certain that the ana tomical cause of the deafness is not situ ated in the brain. It is for the future to
show what chance of improvement such cases have.
Urbantschisch's treatment is also worthy of mention. It consists in regu lar acoustic exercises, intended either to awaken or improve the power of hear ing in deaf-mutes; and there is every reason to look forward to more exhaust ive information as to the results of such treatment with considerable interest.
Instrument intended to facilitate treatment by Gene's auditory exercises, and produce the voice automatically by means of clock-work with an intensity which is subject to regulation. It con sists of a horizontal cylinder run by clock-work, on which wax is spread for receiving the registration. An apparatus placed in front of the cylinder bears a membrane with a rounded style, to which is attached a little special micro phone, with micrometric vise, springs, and levers. An electric current is passed into the special microphone, and into a receiver like that of a telephone. When the receiver is broug,lit to the ear, the words, or sounds, repeated by the phono graph are heard with an intensity which can be regulated at will by increasing the number of cells. By increasing the force of the current the sounds can be made so intense as not to be endured without violent pain. Dussaud gives the receiver of a, similar instrument devised by him to the deaf of all kinds and de grees. He is said to be able to make even deaf-mutes keep time to music and distinuish vowels and words. Each cylinder can repeat 10,000 times what it contains without any alteration. Re engraved, this can be i-epeated forty times; thus each word can be repeated 400,000 times, and there are fifty words on a cylinder. A sixty-cell current is at first needed for the worst cases. At the end of a few nionths one cell will complete the process where a cure is being effected. The number of cells used makes the instrument an audimeter which measures the degree of deafness. On the principle of Urbantschisch and Ge116, who claim that many deaf ears need only education to give them a cer tain amount of hearing power, this ap paratus should be of signal service in the teaching of deaf-mutes. Laborde (Practitioner, Apr., 'OS).
The above remarks on the treatment of deaf-mutism have exclusively dealt with the deafness from which the mutism results. I will not go further into the treatment of mutism by special methods of instruction, because this subject is not included in the aim of this article, which is prepared for those who are to give their attention to the diseases involved.
It will then be seen that when a child is proved to have such deficient power of hearing that mutism is the result, re moval of that deaf-mutism by treatment can only be hoped for in very exceptional cases. Therefore, there is still greater reason for considering the question of the prevention of deaf-mutism. The prin ciple method of obtaining this object must be to submit all children who suffer from deafness which threatens to cause, or has caused, deaf-mutism to a rational examination of tbe ears and of the ad jacent mucous membranes, and eventu ally to make the existing disease the sub ject of rational treatment.