DUMBNESS, the privation of the fa culty of speech. The most general, or rather the sole couse of dumbness, is the want of the sense of hearing. The use of language is originally acquired by imitat ing articulate sounds. From this source of intelligence deaf people are entirely, excluded; they cannot acquire articulate sounds by the ear : unless, therefore, ar ticulation be communicated to them by some other medium, these unhappy peo ple must for ever be deprived of the use of language : and as language is the prin cipal source of knowledge, whoever has the misfortune to want the sense of hear ing must remain in a state little superi or to that of the brute creation. Deaf ness has in all ages been considered as such a total obstruction to speech or written language, that an attempt to teach the deaf to speak or read has been uniformly regarded as impracticable, till Dr. Wallis, and some others, have of late shown, that although deaf people cannot learn to speak or read by the direction of the ear, there are other sources of imi tation by which the same effect may be produced. The organs of hearing and, of speech have little or no connection! Persons deprived of the former general ly possess the latter in such perfection, that nothing' is necessary, .n order to make them articulate, than to teach them how to use these organs. This, in deed, is no easy task ; but experience shews that it is practicable. Mr. Thomas
Braidwood, late of Edinburgh, was per haps the first who ever brought this sur prising art to any degree of perfection. He began with a single pupil in 1764, and since that period has taught great numbers of people born deaf to speak distinctly, to read, to write, to under stand figeres, the principles of religion and morality, &c.
But a new and different method, equal ly laborious and successful, we under stand, is practised by the Abbe de l'Epee of Berlin. We are informed that he be gins his instructions, not by endeavouring to form the organs of speech to articulate sounds, hut by communicating ideas to the mind by means of signs and charac ters : to effect this, he v rites the names of things ; and, by a regular system of signs, establishes a connection between these words and the ideas to be excited by them. After he has thus furnished his pupils with ideas and a medium of communication, he teaches them to ar ticulate and pronounce, and renders them not only grammarians, but logicians. In this manner he has enabled one of his pupils to deliver a Latin oration in public, and another to defend a thesis against the objections of one of his fellow pupils in a scholastic disputation; in which the ar guments of each were communicated to the other, but whether by signs or in Writing is not said.