arts which are affected, that the injury is rather in
the source of this influence than merely in the nerves of the parts;
by the situation of the parts whose actions are impaired, and the
order in which they become affected, that the proximate cause of the
disease is in the superior part of the medulla spinalis; and by the
absence of any injury to the senses and to the intellect, that the
morbid state does not extend to the encephalon.

Uncertainty existing as to the nature of the proximate cause of this
disease, its remote causes must necessarily be referred to with
indecision. Assuming however the state just mentioned as the proximate
cause, it may be concluded that this may be the result of injuries of
the medulla itself, or of the theca helping to form the canal in which
it is inclosed.

The great degree of mobility in that portion of the spine which is
formed by the superior cervical vertebrae, must render it, and the
contained parts, liable to injury from sudden distortions. Hence
therefore may proceed inflammation of quicker or of slower progress,
disease of the vertebrae, derangement of structure in the medulla, or
in its membranes, thickening or even ulceration of the theca, effusion
of fluids, &c.

But in no case which has been noticed, has the patient recollected
receiving any injury of this kind, or any fixed pain in early life in
these parts, which might have led to the opinion that the foundation
for this malady had been thus laid. On the subject indeed of remote
causes, no satisfactory accounts has yet been obtained from any of the
sufferers. Whilst one has attributed this affliction to indulgence in
spirituous liquors, and another to long lying on the damp ground; the
others have been unable to suggest any circumstance whatever, which,
in their opinion, could be considered as having given origin, or
disposed, to the calamity under which they suffered.

Cases illustrative of the nature and cause of this malady are very
rare. In the following case symptoms very similar are observable, so
far as affecting the lower extremities. That the medulla spinalis was
here affected, and in its lower part, is not to be doubted: but this,
unfortunately, was never ascertained by examination. It must be
however remarked, that this case differed from those which have been
given of this disease, in the suddenness with which the symptoms
appeared.

_A. B._ aged twenty-six years, during a course of mercury for a
vener