es into due consideration,
particularly the very gradual manner in which the disease commences,
and proceeds in its attacks; as well as the inability to ascribe its
origin to any more obvious cause, we are led to seek for it in some
slow morbid change in the structure of the medulla, or its investing
membranes, or theca, occasioned by simple inflammation, or rheumatic
or scrophulous affection.

It must be too obvious that the evidence adduced as to the nature of
the proximate and occasional causes of this disease, is by no means
conclusive. A reference to the test therefore which will be yielded by
an examination of some of the more prominent symptoms, especially as
to their agreement with the supposed proximate cause, is more
particularly demanded. Satisfied as to the importance of this part of
the present undertaking, no apology is offered for the extent to which
the examination is carried on.

If the palpitation and the attendant weakness of the limbs, &c. be
considered as to the order in which the several parts are attacked, it
is believed, that some confirmation will be obtained of the opinion
which has been just offered, respecting the cause, or at least the
seat, of that change which may be considered as the proximate cause of
this disease.

One of the arms, in all the cases which have been here mentioned, has
been the part in which these symptoms have been first noticed; the
legs, head, and trunk have then become gradually affected, and lastly,
the muscles of the mouth and fauces have yielded to the morbid
influence.

The arms, the parts first manifesting disordered action, of course
direct us, whilst searching for the cause of these changes, to the
brachial nerves. But finding the mischief extending to other parts,
not supplied with these, but with other nerves derived from nearly the
same part of the medulla spinalis, we are of course led to consider
that portion of the medulla spinalis itself, from which these nerves
are derived, as the part in which those changes have taken place,
which constitute the proximate cause of this disease.

From the subsequent affection of the lower extremities, and from the
failure of power in the muscles of the trunk, such a change in the
substance of the medulla spinalis may be inferred, as shall have
considerably interrupted, and interfered with, the extension of the
nervous influence to those parts, whose nerves are derived from any
portion of the medulla below the par