XVIII. Where a comma would be used if the conjunction were expressed, some stronger point may be used if it be omitted.
Let us get an American revenue as we have got an American Empire. English privileges have made it all that it is; English privileges alone will make it all that it can be.
XIX. A comma is placed after a noun or a pronoun in the vocative case, if a mark of exclamation be not used, or be reserved till the first distinct pause in the sentence.
Yet I own, my lord, that yours is not an uncommon character.
I am, Sir, yours truly, John Smith.
O Italy, gather thy blood into thy heart!
O Thou, who in the heavens dost dwell!
Whether a comma or a mark of exclamation ought to be used after the vocative case, depends entirely on the degree of emphasis with which the words would be spoken. If, in speaking, a slight pause would be made, the comma, not the mark of exclamation, is the proper point.
XX. If a word be repeated in order to give it intensive force, a comma follows it each time that it occurs; but, in the case of an adjective repeated before a noun, not after the last expression of it.
It was work, work, work, from morning till night.