Another cause for the mistaken denial in question must be mentioned.  When travelers or sojourners have become acquainted with signs in any one place they may assume that those signs constitute the sign language, and if they afterwards meet tribes not at once recognizing those signs, they remove all difficulty about the theory of a “one and indivisible” sign language by simply asserting that the tribes so met do not understand the sign language, or perhaps that they do not use signs at all.  This precise assertion has, as above mentioned, been made regarding the Utes and Apaches.  Of course, also, Indians who have not been brought into sufficient contact with certain tribes using different signs, for the actual trial which would probably result in mutual comprehension, tell the travelers the same story.  It is the venerable one of “[Greek:  aglossos],” “Njemez,” “barbarian,” and “stammering,” above noted, applied to the hands instead of the tongue.  Thus an observer possessed by a restrictive theory will find no signs where they are in plenty, while another determined on the universality and identity of sign language can, as elsewhere explained, produce, from perhaps the same individuals, evidence in his favor from the apparently conclusive result of successful communication.

PERMANENCE OF SIGNS.

In connection with any theory it is important to inquire into the permanence of particular gesture signs to express a special idea or object when the system has been long continued.  Many examples have been given above showing that the gestures of classic times are still in use by the modern Italians with the same signification; indeed that the former on Greek vases or reliefs or in Herculanean bronzes can only be interpreted by the latter.  In regard to the signs of instructed deaf-mutes in this country there appears to be a permanence beyond expectation.  Mr. Edmund Booth, a pupil of the Hartford Institute half a century ago, and afterwards a teacher, says in the “Annals” for April, 1880, that the signs used by teachers and pupils at Hartford, Philadelphia, Washington, Council Bluffs, and Omaha were nearly the same as he had learned.  “We still adhere to the old sign for President from Monroe’s three-cornered hat, and for governor we designate the cockade worn by that dignitary on grand occasions three generations ago.”

The specific comparisons made, especially by Dr. Washington Matthews and Dr. W.O.  Boteler, of the signs reported by the Prince of Wied in 1832 with those now used by the same tribes from whom he obtained them, show a remarkable degree of permanency in many of those that were so clearly described by the Prince as to be proper subjects of any comparison.  If they have persisted for half a century their age is probably much greater.  In general it is believed that signs, constituting as they do a natural mode of expression, though enlarging in scope as new ideas and new objects require to be included and though abbreviated as hereinafter explained, do not readily change in their essentials.