210
REPORT OF THE INDIAN HEMP DRUGS COMMISSION, 1893-94.
[APP.
encouraged the development of the sensory-motor disturbance rather than of sleep, that then
the involuntary rocking movements became most marked.
Besides the involuntary rocking movements described, other involuntary movements were
occasionally observed, which are hardly to be explained on the same hypothesis. These
other movements were of two kinds-fine tremor and spasmodic muscular actions. The tremor
involved the whole body and was of intermittent character, an attack of tremor lasting three
or four minutes with an indefinite period of complete freedom. Spasmodic muscular action was
very rarely observed, and usually occurred in the muscles of the head and fore part of the
body, the head being sometimes suddenly and forcibly moved to one or other side.
Difficulty in maintaining the body equilibrium on standing.—When
the rocking movements
had lasted a short time, the animals generally lay down in their habitual posture with their
legs under them. This position apparently enabled them to obtain some respite from the
involuntary movements: and in this position a considerable number fell asleep, the head gra-
dually falling forwards till the nose and the face came in contact with the ground. In those
cats not asleep a roll of the body from side to side was sometimes observed. Within a variable
period of time, half an hour to an hour or even more, from the development of this condition,
those cats which evinced no tendency to sleep, or were only drowsy, were frequently found, on
being disturbed and made to stand up, to have apparently some difficulty in maintaining the
equilibrium of the body in this position. The body swayed from side to side and backwards
and forwards upon the legs, as though too heavy for its supports and likely to fall over. It was
frequently difficult to induce animals in this condition to remain standing, but they were never
observed to fall. On being induced to walk, it was found that this movement was either
perfectly performed, the swaying of the body disappearing entirely, or that the action of the
drug had produced an apparent partial loss of motor power.
Apparent loss of motor power.—In this condition the animal walked with a slow, tottering
and uncertain gait, displaying shakiness and apparent weakness in its movements. It could
not be induced to run; nor yet, on the other hand, was the loss of motor power ever complete.
The weakness was generally most evident in the hind limbs, though it never amounted to
dragging of the limbs. The animal on walking would sway to one or other side, apparently
tending to fall over, and occasionally, on attempting to turn, come down on its hind quarters
and side. The fact that the hind limbs were more affected than the fore served sometimes to
produce a very curious gait; for on walking the hind quarters fell out of line with the rest of the
body, being as it were slued to one side. The peculiar appearance forcibly reminded me of the
characteristic gait of horses suffering from kumri, many cases of which I saw in Upper Burma
during 1887.
In a few instances the apparent loss of power was represented by a peculiar slow, crawling
gait; the animal moving slowly along with its legs doubled up underneath the body and
its belly close to the ground, as though to keep its centre of gravity low down. The loss
of motor power has been described as apparent, and it is submitted that this is the correct
description in the absence of more definite signs of loss of motor power. The phenomena
described may, in the absence of definite signs of muscular paralysis, be accounted for by an
interference with muscular movement, due to error of co-ordination induced by loss of muscular
sense. It frequently happened that in the condition described as one of " difficulty in
maintaining the body equilibrium on standing" no loss of motor power occurred.
Further,
that an effort of the will, as evinced in voluntary movement, was sufficient to restore the
mechanism to its normal state, the difficulty, however, appearing again when the temporary
excitement was withdrawn. The same observation was made with regard to the rocking move-
ments which were found to cease on excitement or voluntary movement. It is natural, then,
to endeavour to explain all these phenomena on the same hypothesis. The same observations
as were advanced in explanation of the "rocking movements" apply with even more force to the
state described as a " difficulty in maintaining the body equilibrium; " for somewhat similar
conditions occur in disease affecting the muscular sense in man. I would suggest that the
rocking movements and altered body equilibrium may be ascribed to the action of the drug
upon the spinal cord, but that when apparent loss of motor power occurs, then the gang-
lionic centres at the base of the brain are also affected. The appearances appear to encourage
the conception that the drug acts upon the central nervous structures and not upon the
peripheral nerve endings. Those animals which displayed the maximum amount of sensory-
motor disturbance evinced no tendency to sleep or loss of their usual instincts.
It has been already stated that the same cats were repeatedly utilised, and it thus came to
be observed that, as regards the action of the drug, certain cats had a constant idiosyncrasy;
that some cats under the influence of the drug were prone to sleep and others to the develop-
ment of the phenomena ascribed to the disturbance of the sensory-motor apparatus; that the
same dose relative to the body weight would in some animals induce disturbance of the sensory-
motor mechanism and in others a varying degree of narcotism. Apart, however, from individual
idiosyncrasy the quantity of the dose was found to play an important part also in determining
the character of the effects produced by the drug. For in certain animals who after certain
doses had been recognised as prone to develop sensory-motor disturbance, without marked sleep
or narcotism, an increased dose, if sufficiently large, could be relied on to produce sleep deep