GERTRUDE                Alas, how is’t with you,

That you do bend your eye on vacancy

And with th’incorporal air do hold discourse?

Forth at your eyes your spirits wildly peep,

And as the sleeping soldiers in th’alarm

Your bedded hair like life in excrements

Start up and stand on end. O gentle son,

Upon the heat and flame of thy distemper

Sprinkle cool patience. Whereon do you look? (3.4.112-120)

Gertrude’s terrified, really properly terrified now, terrified for her son, who seems now, irrefutably, to have gone mad. (Or, if she CAN see the Ghost, as some productions, daringly, decide, then this is a big, big moment in her deciding where her loyalties lie.) Alas, how is’t with you—never mind me, how are YOU? What’s going on, that you do bend your eye on vacancy—stare at nothing, at empty space—and with the in’incorporal air do hold discourse? Why are you apparently having a conversation with—nothing, with AIR? Forth at your eyes your spirits wildly peep—you’re looking properly mad now, staring, your eyes darting around, rolling even. And—an extraordinary simile—as the sleeping soldiers in th’alarm your bedded hair like life in excrements start up and stand on end. If your hair were an army camp, then it’s as if there’s been an attack in the middle of the night, soldiers leaping upright from their beds in shock, all at once. (Excrements at this date refers to anything extruded by the body, including hair and nails.) Hamlet’s every bit as terrified as he was on the battlements, staring, hair standing up. (Another opportunity for David Garrick to employ his famous mechanical wig, hair standing on end at the touch of a button.)* O gentle son, upon the heat and flame of thy distemper sprinkle cool patience. Calm down, let’s just lower the temperature here, please, breathe, slow. (But the mismatch between heat and flame and the delicate suggestion of sprinkle is telling; Gertrude fears that Hamlet really has lost it, that he’s now seriously unbalanced, and that he’s beyond help.) But whereon do you look? What are you staring at??

*the wig is well attested, although probably less dramatic than the modern imagination might supply, more likely a raising of the wig’s back portion than a finger-in-socket effect; it was apparently controlled by a button in his pocket). There are images—as linked here—of Garrick as Hamlet first seeing the Ghost; he was known for his ‘recoil’, the starting back, arms outstretched, a ‘point’ which was much imitated by other actors in the role for decades afterwards.