signs correspond with the general practice of mankind, to nod for "yes," and shake the head for "no." The idea conveyed by nodding seems to correspond with the deaf-and-dumh sign for "truth," made by moving the finger straightforward from the lips, apparently with the sense of "straightforward speaking," while the finger is moved to one side to express "lie," as "sideways speaking." The understanding of nodding and shaking the head as signs of assent and denial appears to belong to uneducated deaf-and-dumb children, and even to those who are only one degree higher than idiots. In a very remarkable dissertation on the art of thrusting knowledge into the minds of such children, Schmalz assumes that they can always make and understand these signs.[1] It is true they may have learnt them from the people who take care of them.
This explanation is, however, somewhat complicated by the Indian signs for "truth," and "lie," given by Burton, who says that the fore-finger extended from the mouth means to "tell truth," "one-word;" but two fingers mean to "tell lies," "double tongue." So to move two fingers before the left breast means, "I don't know," that is to say, "I have two hearts." I found that deaf-and-dumb children understood this Indian sign for "lie " quite as well as their own.
"Good," wave the hand from the mouth, extending the thumb from the index, and closing the other three fingers. This is like kissing the hand as a salutation, or what children call "blowing a kiss," and it is clearly a natural sign, as it is recognized by the deaf-and-dumb language. Dr. James gives the Indian sign as waving the hand with the back upward, in a horizontal curve outwards, the well-known gesture of benediction. At Berlin, a gesture like that of patting a child on the head, accompanied, as of course all these signs are, with an approving smile, is in use. Possibly the ideas of stroking or patting may lie at the bottom of all these signs of approving and blessing.
"Think," pass the fore-finger sharply across the breast from right to left, meaning of course that a thought passes through one's heart.
"Trade, exchange, swop," cross the fore-fingers of both hands
