OBS. 2.—­The interjection O is common to many languages, and is frequently uttered, in token of earnestness, before nouns or pronouns put absolute by direct address; as, “Arise, O Lord; O God, lift up thine hand.”—­Psalms, x, 12. “O ye of little faith!”—­Matt., vi, 30.  The Latin and Greek grammarians, therefore, made this interjection the sign of the vocative case; which case is the same as the nominative put absolute by address in English.  But this particle is no positive index of the vocative; because an independent address may be made without that sign, and the O may be used where there is no address:  as, “O scandalous want! O shameful omission!”—­“Pray, Sir, don’t be uneasy.”—­Burgh’s Speaker, p. 86.

OBS. 3.—­Some grammarians ascribe to two or three of our interjections the power of governing sometimes the nominative case, and sometimes the objective.  First, NIXON; in an exercise entitled, “NOMINATIVE GOVERNED BY AN INTERJECTION,” thus:  “The interjections O!  Oh! and Ah! require after them the nominative case of a substantive in the second person; as, ’O thou persecutor!’—­’O Alexander! thou hast slain thy friend.’ O is an interjection, governing the nominative case Alexander.”—­English Parser, Again, under the title, “OBJECTIVE CASE GOVERNED BY AN INTERJECTION,” he says:  “The interjections O!  Oh! and Ah! require after them the objective case of a substantive in the first or third person; as, ‘Oh me!’ ‘Oh the humiliations!’ Oh is an interjection, governing the objective case humiliations.”—­These two rules are in fact contradictory, while each of them absurdly suggests that O, oh, and ah, are used only with nouns.  So J. M. PUTNAM:  “Interjections sometimes govern an objective case; as, Ah me!  O the tender ties!  O the soft enmity!  O me miserable! O wretched prince!  O cruel reverse of fortune!  When an address is made, the interjection does not perform the office of government.”—­Putnam’s Gram., So KIRKHAM; who, under a rule quite different from these, extends the doctrine of government to all interjections:  “According to the genius of the English language, transitive verbs and prepositions require the objective case of a noun or pronoun after them; and this requisition is all that is meant by government, when we say that these parts of speech govern the objective case.  THE SAME PRINCIPLE APPLIES TO THE INTERJECTION.  ’Interjections require the objective case of a pronoun of the first person after them; but the nominative of a noun or pronoun of the second or third person; as, Ah me!  Oh thou!  O my country!’ To say, then, that interjections require particular cases after them, is synonymous with saying, that they