In Act 1 Scene 5 Lady Macbeth makes a Soliloquy, then again in Act 5 Scene 1. What is the difference between the two?
When I read them I can see that something is definitly different. It seems more apparent that her mind is going in the second one, but what else is different?
You are absolutely right! Her mind is going. But Lady Macbeth also inadvertently implicates her husband and herself in several murders. As she talks in her sleep, she refers to the murders of Duncan (lines 29-35), Lady Macduff ( lines 36-39), and Banquo (lines 53-55). In order to understand the lines, read them as if Lady Macbeth were speaking to her husband, because that is what she's doing. She also reveals that her husband is afraid and she constantly boosts his confidence (lines 32-34, and 38-39). Probably the most quoted line from this soliloquy is "Out, damned spot!" (line 31). She imagines she sees Duncan's blood on her hands (from the night of his murder) and cannot wash it off. Of course the Doctor and Gentlewoman hear all this and (they're not stupid) know what's going on. My favorite quote from this scene is "All the perfumes of Arabia will not sweeten this little hand. Oh, oh, oh!" (lines 43-44). This is ironic considering that in Act I she was calling up spirits to fill her with evil. It would appear that Lady Macbeth is not as tough as she thought.
In the beginning of the play, Lady Macbeth is ruthless, ambitious and full of schemes. She plans the king's murder, she is able to put on a happy face when the king is in her home, even though she knows that he will be murdered that very night. Lady Macbeth has no conscience in the beginning of the play. She is capable of killing without remorse. The only evidence in the early part of the play that Lady Macbeth has any sensitivity or feelings is when she admits that she could not plunge the dagger into King Duncan's chest because while he slept, he looked like her father.
In Act V, Lady Macbeth becomes a victim of her conscience, which suddenly can no longer compartmentalize her actions. Therefore all justification for the murders that have been committed is gone and she is left with the raw reality that she has unleashed an evil force into the world, and now it consumes her.
In the end of the play, Lady Macbeth is ravaged with hallucinations that wash over her with waves of mental anguish, reminding her of how many lives have been lost.
She has put herself outside of the sensibilities of life, law, morality and order. Although she gains something from her deeds, she gives up far more. She is lost in an endless nightmare, unable to sleep. Tormented and unable to free herself. Its like she's locked in the scary fun house and can't get out.