is manifest; since I compare the actual _sounds_. If I say _ka_ and _gee_
are allied, the alliance is concealed; since I compare, not the actual
sounds, but only the _names of the letters_ that express those sounds. Now
in the English language we have (amongst others) the following names of
letters that have a tendency to mislead:--

The sounds fa and va are allied. The names _eff_ and _vee_ conceal this
alliance.

The sounds sa and za are allied. The names _ess_ and _zed_ conceal the
alliance.

In comparing sounds it is advisable to have nothing to do either with
letters or names of letters. Compare the sounds themselves.

s. 106. In many cases it is sufficient, in comparing consonants, to compare
syllables that contain those consonants; e.g., in order to determine the
relations of p, b, f, v, we say pa, ba, fa, va; or for those of s and z, we
say sa, za. Here we compare _syllables_, each consonant being followed by a
vowel. At times this is insufficient. We are often obliged to isolate the
consonant from its vowel, and bring our organs to utter (or half utter) the
imperfect sounds of p', b', t', d'.

s. 107. Let any of the _vowels_ (for instance, the a in _father_) be
sounded. The lips, the tongue, and the parts within the throat remain in
the same position; and as long as these remain in the same position the
sound is that of the vowel under consideration. Let, however, a change take
place in the position of the organs of sound; let, for instance, the lips
be closed, or the tongue be applied to the front part of the mouth: in that
case the vowel sound is cut short. It undergoes a change. It terminates in
a sound that is different, according to the state of those organs whereof
the position has been changed. If, on the vowel in question, the lips be
closed, there then arises an imperfect sound of b or p. If on the other
hand, the tongue be applied to the front teeth, or to the forepart of the
palate, the sound is one (more or less imperfect) of t or d. This fact
illustrates the difference between the vowels and the consonants. It may be
verified by pronouncing the a in _fate_, ee in _feet_, oo in _book_, o in
_note_, &c.

It is a further condition in the formation of a vowel sound, that the
passage of the breath be uninterrupted. In the sound of the l' in _lo_
(isolated from its vowel) the sound is as continuous as it is with the a in
_fate_. Between, however, the consonant l and the vowel a there is this
diff