ive motions of the body; and the unimpaired state
of the intellects; constitute such a degree of accordance as, although
it may not mark an identity of disease, serves at least to show that
nearly the same parts were the seat of the disease in both instances.
Thus we attain something like confirmation of the supposed proximate
cause, and of one of the assumed occasional causes.

Whilst conjecturing as to the cause of this disease, the following
collected observations on the effects of injury to the medulla
spinalis, by Sir Everard Home, become particularly deserving of
attention. It thence appears, that none of the characteristic symptoms
of this malady are produced by compression, laceration, or complete
division of the medulla spinalis.

"Pressure upon the medulla spinalis of the neck, by coagulated blood,
produced paralytic affections of the arms and legs; all the functions
of the internal organs were carried on for thirty-five days, but the
urine and stools passed involuntarily[12].

[Footnote 12: A coagulum of blood, the thickness of a
crown-piece, was found lying upon the external surface of the
dura-matral covering of the medulla spinalis, extending from
the fourth vertebra colli to the second vertebra dorsi. The
medulla spinalis itself was uninjured.]

"Blood extravasated in the central part of the medulla, in the neck,
was attended with paralytic affection of the legs, but not of the
arms[13].

[Footnote 13: The sixth and seventh vertebra colli were
dislocated, the medulla spinalis, externally, was uninjured;
but in the centre of its substance, just at that part, there
was a coagulum of blood nearly two inches in length.]

"In a case where the substance of the medulla was lacerated in the
neck, there was a paralysis in all the parts below the laceration, the
lining of the oesophagus was so sensible, that solids could not be
swallowed, on account of the pain they occasioned[14].

[Footnote 14: The seventh vertebra colli was fractured, and
the medulla spinalis passing through it, was lacerated and
compressed.]

"When the medulla of the back was completely divided, there was
momentary loss of sight, loss of memory for fifteen minutes, and
permanent insensibility in all the lower parts of the body. The skin
above the division of the spinal marrow perspired, that below did not.
The wounded spinal marrow appeared to be extremely sensible[15]."
_Philosophical