call the physiology of this very curious
affection.

There can be no doubt that somnambulism
is hereditary. Horstius mentions three
brothers, who were affected with it at the
same period; and Dr. Willis knew a whole
family subject to it. It is considered by all
medical men as a peculiar form of disease.
It seldom manifests itself before the age of
six, and scarcely ever continues beyond the
sixtieth year. It depends physically upon
the susceptibility or delicacy of the nervous
system; and on this account females are more
liable to it than males; and in youth it manifests
itself more frequently than in mature
age. It is caused mentally by any violent
and profound emotion; as well as by excessive
study, and over-fatiguing the intellectual
faculties. Some persons walk periodically in
their sleep; the fit returns at stated intervals—
perhaps two or three times only in the month.
It has been also observed—although we by no
means vouch for the fact—by an eminent
German physician, that some persons walk at
the full, others at the new moon, but especially
at its changes. One German authority—
Burdach—goes the comical length of asserting
that the propensity of somnambulists to walk
on the roofs of houses is owing to the
attraction of the moon, and that they have a
peculiar pleasure in contemplating the moon, even
in the day time. Whatever may be the cause
of the affection, somnambulism undoubtedly
assumes different degrees of intensity. The
first degree evinces itself by the movements
we have referred to, and by sleep-talking.
This stage is said to be marked by an
impossibility of opening the eyes, which are as if
glued together. There are many curious
circumstances to be observed concerning
sleep-talking. The intonation of the voice
differs from the waking state, and persons for
the most part express themselves with unusual
facility.

We were acquainted with a young lady
accustomed to sit up in bed and recite poetry
in her sleep, whose mother assured us that she
sometimes took cognisance of circumstances
which she could not, in any way, account for.
On one occasion they had been to a ball; and,
after the daughter was in bed and asleep, her
mother went quietly into her room, and taking
away her dress and gloves deposited them in
another room. Presently, as usual, the fair
somnambule began talking in her sleep; her
mother entered, as usual, into conversation
with her; and, at length, asked, " But what
have you done with your new ball-dress?"
"Why, you know," replied she, " you have
laid it on the couch in the drawing-room."
"Yes," continued the mother, " but your
gloves—what have you done with them?"
"You know well enough," she answered, in
an angry tone, " you have locked them up in
your jewel-box." Both answers were correct;
and it may be here observed that somnambulists,
if equivocated with in conversation,
or in any way played upon, will express
themselves annoyed, and betray angry feelings.
The truthfulness of sleep-talking may, we
apprehend, always be relied on. In this state
there is no attempt at evasion; no ingenuity
exercised to disguise anything. The master-
mind of Shakespeare—which seems to have
divined the secrets of Nature, and illustrated
scientific principles before they were discovered
by philosophers—recognised this fact,
in making lago thus rouse the jealousy of Othello:

"There are a kind of men so loose of soul
   That in their sleep will mutter their affairs ,—
   One of this kind is Cassio.
   In sleep I heard him say, ' Sweet Desdemona,
   Let us be wary.'"

Hitherto Othello had borne up manfully
against the cruel insinuations of lago—but
this sleep-revelation "denoted a foregone
conclusion," and carried with it irresistible
conviction. Upon the same principle, Lord
Byron founded the story of " Parisina." Not
long ago a robbery was committed in Scotland,
which was discovered by one of the guilty
parties being overheard muttering some facts
connected with it in his sleep. Mental anxiety
will, almost at any age, give rise to sleep-
talking. The ideas of children during sleep
are often very vivid; nor is there anything
more common than to hear them utter
exclamations of distress, connected, particularly,
with any fears that may, unwisely, have been
impressed on the waking mind. The case of
a little girl came lately under our notice, who
exhibited the most alarming symptoms during
sleep; sobbing and imploring help, under
the imagination that she was being pursued
by an evil spirit; in consequence of a foolish,
fanatical person having frightened her with
threats of this description, while the child,
before going to bed, was saying her prayers.
Very much convulsed inwardly, she was with
difficulty awakened, and for some time
afterwards remained in a state of agitation
bordering on delirium. Assuredly parents cannot
be too careful in endeavouring to make very
young children go to bed with composed and
happy minds, otherwise they know not what
hideous phantom may draw aside the curtain
of their sleep; and, by terrifying the imagination,
produce fits, that may be incurable in
after-life. We believe it quite possible that
epilepsy, itself, may be so produced.

In schools sleep-talking is very common;
anxious pupils, in their sleep, will frequently
repeat a lesson they cannot remember when
awake. The son of the eminent linguist and
commentator, Doctor Adam Clarke, tells us
that his father overheard him, in his sleep,
repeat a Greek verb which he was endeavouring
to learn, and which, the following morning,
he was unable to remember. This is a curious
fact—he knew his lesson in his sleep, but did
not do so when he was awake; the faculty of
memory, however, in a state of somnambulism