Dumbness, is the privation, or want, of the faculty of speech.

This unfortunate defect proceeds chiefly from total and native deaf-nesE; if it arise from a deficiency in the organs necessary for uttering sounds, it is always incurable. Several instances, however, have occured of persons born deaf, who have been taught to speak distinct-ly ; to read, write, understand arithmetic, etc.

The most eminent teachers of the dumb in this country, were,

1. Dr. Wallis, who, in the 61st number of the Philosophical Transactions, gives an account of two persons he had taught to speak ; and, in the 245th number of the same work, his method is explained.

2. Mr. Thomas Braidwood, late of Edinburgh, who is perhaps the first person that ever brought the surprizing art of imparting speech to dumb persons to any degree of perfection. He first com-menced his useful labours in 1764, and, in the course of a few years, enabled many to speak, write, etc. We regret that we cannot communicate a clear idea of his method, which indeed will not admit of being so fully explained in writing, as to enable any person to teach it. - Mr. B. used to pronounce first the sound of a, slowly, at the same time pointing out the figure of that letter, and making his pupil watch the motion of his mouth and throat; he then put his finger into the pupil's mouth, depressing or elevating his tongue, and making him keep the parts in that position. Next, he laid hold of the outside of the wind-pipe, and squeezed it in a certain direction, which we confess ourselves utterly unable to describe. While he was pronouncing the letter a, his pupil was anxiously imitating him, uncertain of, or rather not comprehending, the nature of the sound he was required to utter. In this manner, Mr. Braidwood proceeded, till his tyro learned to pronounce the sounds of the different letters of the alphabet. Mr.B. then continued in the same order to join vowels and consonants, till at length his pupil was enabled both to speak and read.

It would be injustice to omit mentioning the labours of the very ingenious Abbe I.'Epee, of Berlin, who has deservedly acquired great celebrity by his method of teaching dumb persons to speak, by signs or characters. For an account of his plan, we must refer our readers to the "New Memoirs of the Royal Academy of Sciences," etc. of Berlin for the year 1785 ("Noveaux Memoires de L' Academic Royale," etc.) in which they will find a short account confirmed by facts.