DEAF MUTE. A person who is deaf and dumb. Those who are born deaf or who lose their hearing at a very early age are also dumb, because they have not learned to speak by hear ing others speak. They should not, therefore, be classed with those who cannot articulate words because of defect in the speech centres of the brain or disease of the organs of articula tion. Persons who have learned to speak. and then become deaf, do not become mute, though the quality of voice used is often harsh and unnatural: and if the deprivation of hearing occurred in childhood the voice often remains childish. Deafness from birth (congenital deaf ness) is probably dile to arrest of development in the embryo. The condition is found in certain instances as a family trait, in families with neu rotic inheritances. Alcoholism and insanity are found in such families; and, besides these. paren tal syphilis is frequently a causal influence in producing congenital deafness. The intermar riage of near relatives who inherit similar disease tendencies has been a large factor in the production of deaf offspring. Boudin, of Paris, asserts that about 25 per cent. of the deaf mutes of France are the offspring of con sanguineous marriages. In England. lbixton places the figures at 10 per cent. in his experi ence. Bemiss, of Louisville, hy., records that over 10 per cent. of the deaf and dumb through out the country at large are the offspring of kin dred parents. Howe, of Boston. gave similar testimony. The principal causes of acquired deafness have been noted under DEAFNESS. In early historical times, statesmen, lawyers, and philosophers agreed that deaf mutes were capable of being educated. Legally, deaf mutes were then almost everywhere in the same position as idiots and madmen. The Roman law held them to be incapable of consent, and conse quently unable to enter into a legal obligation or contract. In Franee, deaf mutes were vonsidered a disgrace to their parents, and were kept. in seclusion in eonvents and asylums. 'Vet, ex amples of considerable capacity on the part of deaf mutes were not unknown in ancient times and in the Middle Ages. Pliny mentions a sue cessful den f-innte painter a t Rome. The Venerable Bede, about the close of Hie seventh century, gives an account of a dumb youth who was taught by an early English bishop, Saint John of Beverley. to repeat word: and sentences after him. Rociolphu• Agricola, of Groningen (1442 85), mentions a deaf mute who had received in struction and could write.
The credit for the first systematic examination of the problem from a philosophical point of view is due to Jerome Cardan tq.v.), whose con
clusion was that "written characters and ideas may be connected together without the interven tion of sotutds." This authoritative declaration had the effect of arousing widespread interest in the problem, and Pedro Ponce (1520-8-1), a Spanish Benedictine monk, undertook to give regular instruction to the deaf and dumb. Pasch, a clergyman of Brandenburg, was the next teacher of note, and lie was followed by Juan Pablo Bonet, secretary to the constable of Cas tile, Spain, also a Benedictine monk. Bonet published a work in 1620, which is the earliest known treatise on the subject, and which prob ably embodied the ideas of Cardan. It con tained a manual alphabet differing much from that described by Bede, and in the main identical with the single-band manual in use to-day. The treatise of Dr. John Buhuer, an English physi cian. followed in DAS; and this was succeeded by the work of Dr. \Valli,. an Oxford professor of mathematics. In 1669 Dr. William Holder, rector of Bletebington, published a similar work, and in 1670 George Sib-cote put forth another work. A very able and philosophical treatise was published in 1680 by George Dalgarno, of Aberdeen, Scotland, which received high praise from Leibnitz, together with an earlier work. to which Wallis and Wilkins are both said to lie indebted. In the first rank among early teach ers of deaf mutes stands John Conrad Amman, a Swiss physician residing in Amsterdam, who, in 1692, reduced the methods then known to an exact art. as described in his Sardus Lognens. France, late to recognize the possibilities of deaf-mute instruction, furnished many enthusi astic advocates of it, as P()re Vanin, Ernaud. Rodriguez Pereira (a Spaniard who settled in France). and the Deschamps. stands the Charles Michel de 1'Ep6e. of Paris, who systematized the instruction of deaf mutes in France. in 1760. in Ids own school. His successor, Sicard. as well as hard. fol lowed his methods. It was in 1760, also, that Thomas Braidwood established. at Edinburgh, the first private school for deaf mutes in the British dominions. This school, in which Wal lis's plan of instruction was followed. was the model of the earlier British institutions. In 1783 this school was removed to Hackney. near London, and probably led to the establishment of the London Asylum, in 1792. Dr. Joseph 'Watson, a nephew and former assistant of Mr. Braidwood, was its first principal.