hock equal to that of electricity, and
induced him to exclaim, "Why do you wish to shoot me in the eyes?" These
are exceptions; as a general rule, the eye during somnambulism is
insensible, and the pupil will not contract, though the most vivid flash
of light be directed upon it. It also should be observed that although
somnambulists will light a candle, it does not follow that they are
guided by its light, or that they really see any thing by it. Their
movements may still be purely automatic. This curious circumstance is
finely illustrated by Shakspeare, who describes the Lady Macbeth walking
in her sleep with a lighted taper in her hand:

"_Gentlewoman._--Lo, yon, here she comes: This is her very guise,
and upon my life, fast asleep.

_Doctor._--How came she by that light?

_Gentlewoman._--Why, it stood by her. She has light by her
continually--'tis her command.

_Doctor._--You see her eyes are open--

_Gentlewoman._--Ay--but their sense is shut."

It is related of Negretti, a sleep-walker, that he would sometimes carry
about with him a candle as if to give him light in his employment; but,
on a bottle being substituted, he took it and carried it, fancying that
it was a candle. Castelli, another somnambulist, was found by Dr. Soames
translating Italian into French, and looking out the words in his
dictionary. His candle being purposely extinguished, he immediately
began groping about, as if in the dark, and although other candles were
in the room, he did not resume his occupation until he had relighted his
candle at the fire. In this case we may observe that he could not see,
excepting with the candle he had himself lighted, and he was insensible
to every other, excepting that on which his attention was fixed.

How are these curious anomalies to be explained? There is, it appears to
us, a striking analogy between the actions as they are performed by the
blind and those executed by somnambulists, who are insensible to light;
the exaltation of the sense of touch, in blindness, is so great, that
some physiologists have conceived the existence of a _sixth_ sense--the
muscular sense--which communicates the impression before the actual
contact of objects. This muscular sense is supposed by Dr. Fowler to
adjust the voice, the eye, and the ear, to the distances at which sounds
are to be heard, and objects seen. It may, perhaps, be described as a
peculiar exaltation of the sense of fee