[…] the part of phonetics, as a branch of linguistic science, is to follow and describe, as closely as may be, the voluntary changes of position of the mouth-organs, etc., which determine the various sounds.
- Whitney (1875), a pag.60

[…] the relation of vowel and consonant: which, though their distinction is of the highest importance in phonetics, are by no means separate and independent systems; but only poles, as it were, in one continuous unitary series, and with a doubtful or neutral territory between them […].
- Whitney (1875), a pag.68

It must be carefully noted [...] that the reach of phonetics, its power to penetrate to the heart of its facts and account is only limited.
- Whitney (1875), a pag.73