It is unnecessary further to trace these dawnings of speech, or to describe the satisfaction that is felt, when the child by this commutation of perceptions for words, can communicate the wonders it has seen, the delicacies it has tasted, or the flattering commendations bestowed on its person and accomplishments. This commutation confers additional satisfaction by being enabled to invest the object of immediate perception with an appropriate and intelligible name. Thus by the repeated exercise of this commutation, which soon becomes confirmed into habit, we speak of the past, by the assistance of memory, with the correctness and feeling of the present. At a certain age we learn to discriminate the characters that compose words, (letters)--the order in which they are placed, (orthography,) and with greater difficulty, the position of these words, to convey a definite and connected meaning. When reading has been fully attained, it must be recollected that all the sentences in the volume we peruse, are composed of individual words, that are examples of the commutation mentioned; and although the objects are absent, and the actions have been long since performed, often for centuries, we are interested in the narrative, and bestow the appropriate tribute of sympathy or admiration. Words, thus impregnated with definite meaning, become the floating currency of the mind, are the efficient materials of Thought, and of its perspicuous expression. It has been frequently remarked, that the mind is more delighted by making distant excursions, than in the examination of surrounding objects, or of those directly obvious. Such immediate assistance for the pursuit and development of this inquiry is presented in two remarkable instances, where Nature digresses from her usual course, and which are not of rare occurrence. 1st. Some persons are born with their ears impervious to sound, and as language is acquired by imitation,[4] such as are deaf, remain mute or dumb.[5] With the exception of the sense of hearing, they are like animals the creatures of perception. Some have displayed considerable curiosity in examining objects by the eye, and by the organs of touch, taste, and smell: but they do not, with these elements of knowledge, progressively advance in intelligence, until they have been circuitously taught the characters that are the constituents of words, and also to comprehend, that the word itself is the commuted substitute for the object perceived. Notwithstanding these deficiencies, and disqualifications for human intercourse, these deaf, and consequently dumb persons, must be, in a very high degree, the subjects of Ideas, or of those phantasms that are associated with visual perception.