Ida. Is it not wonderful that the somnambulist will incur great dangers with complete sang-froid? They will walk over
——“Torrents roaring loud,
On the unsteadfast footing of a spear;”
or scale the gigantic precipice, the mere contemplation of which would fright their mind from its propriety, when awake. I remember to have read of a French Jew, who walked by chance across a dangerous pass over a brook, in the dark, without the slightest fear or harm. The next day, perceiving what danger he had incurred, he fell down dead.
Ev. It is equally curious that a concentration of nervous energy, which is here the result of unconsciousness, should also be produced by fear in some cases, which, in others, paralyses; but this is indeed a slight degree of heroism, or energy of despair. Thus we leap far higher, and run much faster, when danger threatens, than we could believe.
These are all very apt illustrations of somnambulism. I will check myself in quotations of more, as the phenomena may closely resemble each other.
But what is its philosophy, and how can I venture on its explanation, which involves the most intricate pathology of the nervous system? unless, with the self-complacency of quaint old Burton, I cut the Gordian knot by this affirmation,—“There is nothing offends but a concourse of bad humours, which trouble the phantasy. These vapours move the phantasy, the phantasy the appetite, which, moving the animal spirits, causeth the body to walk up and down, as if it were awake.”
Thus much I may expound to you, if I am again allowed to run up our scientific scale. The philosophy of the dream and of incubus refers to the activity of the brain with a passive body; for somnambulism, we require an active body, with an unconscious brain.
Now there are four sources of nervous influence:—the brain and cerebellum, within the skull; the marrow in the spinal canal; and the nervous bundles in the large cavities, termed ganglia.
It is on the independent or unconscious function of the marrow, chiefly, that those mysterious actions, which do not seem to be willed by a conscious mind, depend.