Should the approach of this wild river break,
And stand unshaken yours."
Your Leeds correspondent would read:
"I do profess
That for your highness' good I ever labour'd
More than mine own.—That, am I, have, and will be,
Though all the world should crack their duty to you
And throw it from their soul," &c.
For his arguments I must refer to his note (p. 111. antè), merely observing that I cannot conceive how any alteration in the punctuation of the King's speech could connect it with this! Making That emphatic helps nothing, as there is no antecedent to which it can refer; and if "we can by no means part with have," we must interpolate been after it to make it any way intelligible, to the marring of the verse.
With regard to the substitution of lack for crack in my former note, it should be recollected that I then said "I do not insist upon this." We might, however, substitute slack, if change should be deemed necessary, and it would be still nearer in form to the suspected word.