§ 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 difference: with a, the passage of the breath is uninterrupted; with l, the tongue is applied to the palate, breaking or arresting the passage of the breath. § 108. The primary division of our articulate sounds is into vowels and consonants. The latter are again divided into liquids (l, m, n, r) and mutes (p, b, f, v, t, d, k, g, s, z, &c.). § 109. _Sharp and flat._--Take the sounds of p, f, t, k, s. Isolate them from their vowels, and pronounce them. The sound is the sound of a whisper. Let b, v, d, g, z, be similarly treated. The sound is no whisper, but one at the natural tone of our voice. Now p, f, t, k, s (with some others that will be brought forward anon) are _sharp_, whilst b, v, &c., are _flat_. Instead of _sharp_, some say _hard_, and instead of _flat_, some say _soft_. The terms _sonant_ and _surd_ are, in a scientific point of view, the least exceptionable. They have, however, the disadvantage of being pedantic. The _tenues_ of the classics (as far as they go) are sharp, the _mediæ_ flat. § 110. _Continuous and explosive._--Isolate the sounds of b, p, t, d, k, g. Pronounce them. You have no power of prolonging the sounds, or of resting upon them. They escape with the breath, and they escape at once. It is not so with f, v, sh, zh. Here the breath is transmitted by degrees, and the sound can be drawn out and prolonged for an indefinite space of time. Now b, p, t, &c., are explosive, f, v, &c., continuous. § 111. Concerning the vowels, we may predicate a) that they are all continuous, b) that they are all flat. Concerning the liquids, we may predicate a) that they are all continuous, b) that they are all flat.