rt. He was scarcely able to feed himself. He had
written hardly intelligibly for the last three years; and at present
could not write at all. His attendants observed, that of late the
trembling would sometimes begin in his sleep, and increase until it
awakened him: when he always was in a state of agitation and alarm.

On being asked if he walked under much apprehension of falling
forwards? he said he suffered much from it; and replied in the
affirmative to the question, whether he experienced any difficulty in
restraining himself from getting into a running pace? It being asked,
if whilst walking he felt much apprehension from the difficulty of
raising his feet, if he saw a rising pebble in his path? he avowed, in
a strong manner, his alarm on such occasions; and it was observed by
his wife, that she believed, that in walking across the room, he would
consider as a difficulty the having to step over a pin.

The preceding cases appear to belong to the same species: differing
from each other, perhaps, only in the length of time which the disease
had existed, and the stage at which it had arrived.

CHAP. II.

PATHOGNOMONIC SYMPTOMS EXAMINED--_TREMOR COACTUS_--_SCELOTYRBE
FESTINANS_.

It has been seen in the preceding history of the disease, and in the
accompanying cases, that certain affections, the tremulous agitations,
and the almost invincible propensity to run, when wishing only to
walk, each of which has been considered by nosologists as distinct
diseases, appear to be pathognomonic symptoms of this malady. To
determine in which of these points of view these affections ought to
be regarded, an examination into their nature, and an inquiry into the
opinions of preceding writers respecting them, seem necessary to be
attempted.

* * * * *

I. _Involuntary tremulous motion, with lessened voluntary muscular
power, in parts, not in action, and even supported._

It is necessary that the peculiar nature of this tremulous motion
should be ascertained, as well for the sake of giving to it its
proper designation, as for assisting in forming probable conjectures,
as to the nature of the malady, which it helps to characterise.
Tremors were distinguished by Juncker into Active, those proceeding
from sudden affection of the minds, as terror, anger, &c. and Passive,
dependant on debilitating causes, such as advanced age,