aspersion, session, passion, mission, compulsion_: and that of _zh_,
after a vowel; as in _evasion, elision, confusion_.

In the verb _assure_, and each of its derivatives, also in the nouns
_pressure_ and _fissure_, with their derivatives, we hear, according to
Walker, the sound of _sh_ for each _s_, or twice in each word; but,
according to the orthoepy of Worcester, that sound is heard only in the
accented syllable of each word, and the vowel in each unaccented syllable
is _obscure_.

_S_ is silent or mute in the words, _isle, island, aisle, demesne, corps_,
and _viscount_.

XX. OF THE LETTER T.

The general sound of the consonant _T_, is heard in _time, letter, set_.
_T_, immediately after the accent, takes the sound of _tch_, before _u_,
and generally also before _eou_; as in _nature, feature, virtue, righteous,
courteous_: when _s_ or _x_ precedes, it takes this sound before _ia_ or
_io_; as in _fustian, bastion, mixtion_. But the general or most usual
sound of _t_ after the accent, when followed by _i_ and an other vowel, is
that of _sh_; as in _creation, patient, cautious_.

In English, _t_ is seldom, if ever, silent or powerless. In _depot_,
however, a word borrowed from the French, we do not sound it; and in
_chestnut_, which is a compound of our own, it is much oftener written than
heard. In _often_ and _soften_, some think it silent; but it seems rather
to take here the sound of _f_. In _chasten, hasten, fasten, castle, nestle,
whistle, apostle, epistle, bustle_, and similar words, with their sundry
derivatives, the _t_ is said by some to be mute; but here it seems to take
the sound of _s_; for, according to the best authorities, this sound is
beard twice in such words. _Th_, written in Greek by the character called
_Theta_, ([Greek: th] or O capital, [Greek: th] or [Greek: th] small,)
represents an elementary sound; or, rather, two distinct elementary sounds,
for which the Anglo-Saxons had different characters, supposed by Dr.
Bosworth to have been applied with accurate discrimination of "the _hard_
or _sharp_ sound of _th_," from "the _soft_ or _flat_ sound."--(See
_Bosworth's Compendious Anglo-Saxon Dictionary_, p. 268.) The English _th_
is either sharp, as in _thing, ethical, thinketh_; or flat, as in _this,
whither, thither_.

"_Th initial_ is sharp; as in _thought_: except in _than, that, the, thee,
their, them, then, thence, there, these, they, thine, this, thither, those,
thou, thus, thy_, and