OBS. 16.—­The chief exceptions, or irregularities, in the formation of the possessive singular, are, I think, to be accounted mere poetic licenses; and seldom, if ever, to be allowed in prose.  Churchill, (closely copying Lowth,) speaks of them thus:  “In poetry the s is frequently omitted after proper names ending in s or x as, ‘The wrath of Peleus’ son.’ Pope. This is scarcely allowable in prose, though instances of it occur:  as, ‘Moses’ minister.’ Josh., i, 1. ’Phinehas’ wife.’ 1 Sam., iv, 19.  ‘Festus came into Felix’ room.’ Acts, xxiv, 27.  It was done in prose evidently to avoid the recurrence of a sibilant sound at the end of two following syllables; but this may as readily be obviated by using the preposition of, which is now commonly substituted for the possessive case in most instances.”—­Churchill’s New Gram., p. 215.  In Scott’s Bible, Philadelphia, 1814, the texts here quoted are all of them corrected, thus:  “Moses’s minister,”—­“Phinehas’s wife,”—­“Felix’s room.”  But the phrase, “for conscience sake,” (Rom., xiii, 5,) is there given without the apostrophe.  Alger prints it, “for conscience’ sake,” which is better; and though not regular, it is a common form for this particular expression.  Our common Bibles have this text:  “And the weaned child shall put his hand on the cockatrice’ den.”—­Isaiah, xi, 8.  Alger, seeing this to be wrong, wrote it, “on the cockatrice-den.”—­Pronouncing Bible. Dr. Scott, in his Reference Bible, makes this possessive regular, “on the cockatrice’s den.”  This is right.  The Vulgate has it, “in caverna reguli;” which, however, is not classic Latin.  After z also, the poets sometimes drop the s:  as,

   “Sad was the hour, and luckless was the day,
    When first from Shiraz’ walls I bent my way.”—­Collins.

OBS. 17.—­A recent critic, who, I think, has not yet learned to speak or write the possessive case of his own name properly, assumes that the foregoing occasional or poetical forms are the only true ones for the possessive singular of such words.  He says, “When the name does end with the sound of s or z, (no matter what letter represents the sound,) the possessive form is made by annexing only an apostrophe.”—­O.  B. Peirce’s Gram., p. 44.  Agreeably to this rule, he letters his work, “Peirce’ Grammar,” and condemns, as bad English, the following examples and all others like them:  “James Otis’s letters, General Gates’s command, General Knox’s appointment, Gov. Meigs’s promptness, Mr. Williams’s oration, The witness’s deposition.”—­Ib., p. 60.  It is obvious that this gentleman’s doctrine and criticism are as contrary to the common practice of all good authors, as they are to the common