In sleep there is no struggle of the will; and he communes with his own
heart, which is beating so low; a condition that must be caused by a sense
of "something lost."
"Break," he says, still addressing his heart, but in metaphor;
"Break, thou deep vase of chilling tears,
That grief hath shaken into frost."
This must refer to the scientific fact, that water can be lowered in
temperature below the freezing point, without solidifying; but it expands
at once into ice if disturbed; and the suddenness of the expansion breaks
the containing vessel.
Clouds of undefined trouble, such as "dreams are made of," pass "below the
darken'd eyes," that is, figure themselves on the brain under the eyelids;
but on awaking, the will reasserts its power, and protests against the
folly of such mourning. He would therefore dismiss the phantom, Sorrow.