[…] the relations 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: they are simply the opener and closer sounds of the alphabetic system.
- Whitney (1875), a pag.68

Every alphabetic system must start from the sound ‘a’ (of ‘far’, ‘father’); for this is the fundamental tone of the human voice, the purest intonated product of lungs and throat.
- Whitney (1875), a pag.60