not by Sicard.  Some of his thoughts should be quoted:  “As I think the eye to be as docile as the ear; so neither see I any reason but the hand might be made as tractable an organ as the tongue; and as soon brought to form, if not fair, at least legible characters, as the tongue to imitate and echo back articulate sounds.”  A paragraph prophetic of the late success in educating blind deaf-mutes is as follows:  “The soul can exert her powers by the ministry of any of the senses:  and, therefore, when she is deprived of her principal secretaries, the eye and the ear, then she must be contented with the service of her lackeys and scullions, the other senses; which are no less true and faithful to their mistress than the eye and the ear; but not so quick for dispatch.”

In his division of the modes of “expressing the inward emotions by outward and sensible signs” he relegates to physiology cases “when the internal passions are expressed by such external signs as have a natural connection, by way of cause and effect, with the passion they discover, as laughing, weeping, frowning, &c., and this way of interpretation being common to the brute with man belongs to natural philosophy.  And because this goes not far enough to serve the rational soul, therefore, man has invented Sematology.”  This he divides into Pneumatology, interpretation by sounds conveyed through the ear; Schematology, by figures to the eye, and Haptology, by mutual contact, skin to skin.  Schematology is itself divided into Typology or Grammatology, and Cheirology or Dactylology.  The latter embraces “the transient motions of the fingers, which of all other ways of interpretation comes nearest to that of the tongue.”

As a phase in the practice of gestures in lieu of speech must be mentioned the code of the Cistercian monks, who were vowed to silence except in religious exercises.  That they might literally observe their vows they were obliged to invent a system of communication by signs, a list of which is given by Leibnitz, but does not show much ingenuity.

A curious description of the speech of the early inhabitants of the world, given by Swedenborg in his Arcana Coelestia, published 1749-1756, may be compared with the present exhibitions of deaf-mutes in institutions for their instruction.  He says it was not articulate like the vocal speech of our time, but was tacit, being produced not by external respiration, but by internal.  They were able to express their meaning by slight motions of the lips and corresponding changes of the face.

[Illustration:  Fig. 64.—­Group from an ancient Greek vase.]