[…] vocal utterance has become everywhere the leading means of expression, and has so multiplied its resources that tone, and still more gesture, has assumed the subordinate office of aiding the effectiveness of what is uttered. And the lower the intellectual condition of the speaker and the spoken-to, the more indispensable is the addition of tone and gesture.
- Whitney (1875), a pag.294

[…] we have […] our “natural” expression, in grimace, gesture, and tone; and we make use of it: on the one hand, for communication where the usual means is made of no avail- as between men of different tongues who by deafness are cut off from the use of the speech- and, on the other hand, for embellishing and explaining and enforcing our ordinary language […].
- Whitney (1875), a pag.282-283

If the Darwinian theory is true and man a development out of some lower animal, it is at any rate conceded that the last and nearest transition-forms have perished, perhaps exterminated by him in his struggle for existence […] if they could be restored, we should find the transition-forms toward our speech to be, not at all a minor provision of natural articulate signs, but an inferior system of conventional signs, in tone, gesture and grimace.
- Whitney (1875), a pag.291

The basis [of origin of language] was the natural cries of human beings, expressive of their feelings, and capable of being understood as such by their fellows […] it is not to be maintained that this was the only, or even the principal, means of expression. Gesture and grimace are every whit as natural and as immediately intelligible; and in the undeveloped condition of expression every available means will unquestionably have been resorted to, perhaps with a long predominance of the visible over the audible.
- Whitney (1875), a pag.287

The first [gesture and grimace] is chiefly employed by mutes- though not in its purity, inasmuch as these unfortunates are wont to be trained and taught by those who speak, and their visible signs are more or less governed by habits born of utterance; going even so far as slavishly to represent the sounds of speech.
- Whitney (1875), a pag.2

We say with literal truth that a look, a tone, a gesture, is often more eloquent than elaborate speech.
- Whitney (1875), a pag.283