Now in certain languages the _true_ aspirates are of common occurrence, _i.e._, sounds like the _t_ in _nuthook_, the _ph_ in _haphazard_, &c., are as frequent as the sounds of _p_, _b_, _s_, &c. In the spelling of these sounds by means of the English we are hampered by the circumstance of _th_ and _ph_ being already used in a different sense. * * * * * {157} CHAPTER IV. EUPHONY; THE PERMUTATION AND THE TRANSITION OF LETTERS. s. 224. 1. Let there be two syllables, of which the one ends in _m_, and the other begins with _r_, as we have in the syllables _num-_ and _-rus_ of the Latin word _numerus_. 2. Let an ejection of the intervening letters bring these two syllables into immediate contact, _numrus_. The _m_ and _r_ form an unstable combination. To remedy this there is a tendency (mark, not an absolute necessity) to insert an intervening sound. In English, the form which the Latin word _numerus_ takes is _num_b_er_; in Spanish, _nom_b_re_. The _b_ makes no part of the original word, but has been inserted for the sake of euphony; or, to speak more properly, by a euphonic process. The word euphony is derived from [Greek: eu] (_well_), and [Greek: phone] (_f[^o]nae_, a voice). The province of euphony has not been very accurately determined. s. 225. In the word _number_, _nombre_, the letter inserted was _b_; and for _b_ being the particular letter employed, there is a reason derived from the _system_ of articulate sounds. 1. That the letter inserted should be a consonant is evident. The _vowel_ _e_ (in _num_e_rus_) had been previously ejected. 2. That it should be a mute is evident. A liquid would have given the unstable or unpronounceable combinations _mnr_, _mlr_, _mrr_, _mmr_. 3. That it should be a consonant, either of series _b_ or of series _s_, was natural; it being series _b_ and series _s_ with which _m_ and _r_ are respectively connected. 4. That it should be a consonant of series _b_, rather than one of series _s_, we collect from the fact that _msr_ (_numsrus_) or _mzr_ (_numzrus_) give inharmonious, and, consequently, unstable combinations. {158} 5. That of the _b_ series, it should be _b_ or _v_ (flat) rather than _p_ or _f_ (sharp), we infer from the fact of _m_ and _r_ both being flat. 6. Of _v_ and _b_, the latter alone gives a stable combination, so that we have the Spanish form _nom_b_re_, and not _nom_v_re_. In this we have an illustration of the use of attending to the nature and connections of articulate sounds in general. s. 226. The affinity of _m_ for the series _b_, of _n_ for the series _t_, gives occasion to further euphonic changes. The combinations _mt_, _md_, _mth_, _mdh_, are unstable. The syllables _emt_, _emd_, are liable to one of two modifications. Either _p_ or _b_ will be inserted, and so make them _empt_ (as in _tempt_), _embd_ (as in _Embden_), or else the _m_ will become _n_, forming the syllable _ent_, _end_, _enth_, _endh_.