S.
S has a hissing sound, as sibilation, sister.
A single s seldom ends any word, except in the third person of verbs, as loves, grows; and the plurals of nouns, as trees, bushes, distresses; the pronouns this, his, ours, yours, us; the adverb thus; and words derived from Latin, as rebus, surplus; the close being always either in se, as house, horse, or in ss, as grass, dress, bliss, less, anciently grasse, dresse.
S, single at the end of words, has a grosser sound, like that of z, as trees, eyes, except this, thus, us, rebus, surplus.
It sounds like z before ion, if a vowel goes before it, as intrusion; and like s, if it follows a consonant, as conversion.
It sounds like z before e mute, as refuse, and before y final, as rosy; and in those words, bosom, desire, wisdom, prison, prisoner, present, present, damsel, casement.
It is the peculiar quality of s, that it may be sounded before all consonants, except x and z, in which s is comprised, x being only ks, and z a hard or gross s. This s is therefore termed by grammarians suæ potestatis litera; the reason of which the learned Dr. Clarke erroneously supposed to be, that in some words it might be doubled at pleasure. Thus we find in several languages.
Σβεννυμι, scatter, sdegno, sdrucciolo, sfavellare, σφιγξ, sgombrare, sgranare, shake, slumber, smell, snipe, space, splendour, spring, squeeze, shrew, step, strength, stramen, stripe, sventura, swell.
S is mute in isle, island, demesne, viscount.