I.v.39 (422, 8) The raven himself is hoarse] Dr. Warburton reads,

--_The raven himself's_ not _hoarse_.

Yet I think the present words may stand. The messenger, says the
servant, had hardly breath _to make up his message_; to which the lady
answers mentally, that he may well want breath, such a message would add
hoarseness to the raven. That even the bird, whose harsh voice is
accustomed to predict calamities, could not _croak the entrance of_
Duncan but in a note of unwonted harshness.

I.v.42 (422, 2) mortal thoughts] This expression signifies not _the
thoughts of mortals_, but _murtherous, deadly_, or _destructive
designs_. So in act 5,

_Hold fast the_ mortal _sword_.

And in another place,

_With twenty_ mortal _murthers_.

I.v.47 (422, 3) nor keep peace between/The effect, and it!] The intent
of lady Macbeth evidently is to wish that no womanish tenderness, or
conscientious remorse, may hinder her purpose from proceeding to effect;
but neither this, nor indeed any other sense, is expressed by the
present reading, and therefore it cannot be doubted that Shakespeare
wrote differently, perhaps thus,

_That no compunctious visitings of nature