s. 219. _Evolution of sounds._--Let there be a language where there is no such a sound as that of _z_, but where there is the sound of _s_. The sound of _z_ may be evolved under (amongst others) the following conditions. 1. Let there be a number of words ending in the flat mutes; as _slab_, _stag_, _stud_, &c. 2. Let a certain form (the plural number or the genitive case) be formed by the addition of _is_ or _es_; as _slabis_, _stages_, _studes_, &c. 3. Let the tendency that words have to contract eject the intermediate vowel, _e_ or _i_, so that the _s_ of the inflexion (a _sharp_ mute) and the _b_, _d_, _g_, &c. of the original word (_flat_ mutes) be brought into juxta-position, _slabs_, _studs_, _stags_. There is then an incompatible termination, and one of two changes must take place; either _b_, _d_, or _g_ must become _p_, _t_, or _k_ (_slaps_, _staks_, _stuts_); or _s_ must become _z_ (_stagz_, _studz_, _slabz_). In this latter case _z_ is evolved. Again, Let there be a language wherein there are no such sounds as _sh_, _ch_ (_tsh_), or _j_ (_dzh_); but where there are the sounds of _s_, _t_, _d_, and _y_. Let a change affect the unstable combinations _sy_, _ty_, _dy_. From this will arise the evolved sounds of _sh_, _ch_, and _j_. The phenomena of evolution help to determine the pronunciation of dead languages. s. 220. _On the value of a sufficient system of sounds._--In certain imaginable cases, a language may be materially affected by the paucity of its elementary articulate sounds. In a given language let there be the absence of the sound _z_, the other conditions being those noted in the case of the words _stag_, _slab_, _stud_, &c. Let the intermediate vowel be ejected. Then, instead of the _s_ being changed into an evolved _z_, let the other alternative take place; so that the words become _staks_, _slaps_, _stuts_. In this latter case we have an alteration of the original word, brought about by the insufficiency of the system of articulate sounds. s. 221. _Double consonants rare._--It cannot be too clearly understood that in words like _pitted_, _stabbing_, _massy_, &c. there is no real reduplication of the sounds of _t_, _b_, and _s_, respectively. Between the words _pitted_ (as with the small-pox) and _pitied_ (as being an object of pity) there is a difference in {155} spelling only. In speech the words are identical. _The reduplication of the consonant is in English, and the generality of languages, a conventional mode of expressing upon paper the shortness (dependence) of the vowel that precedes._