192 REPORT OF THE INDIAN HEMP DRUGS COMMISSION, 1893-94.          [APP.

REPORT BY BRIGADE-SURGEON-LIEUTENANT-COLONEL D. D. CUNNING-
HAM, F.R.S., C.I.E., ON THE NATURE OF THE EFFECTS ACCOMPANYING
THE CONTINUED TREATMENT OF ANIMALS WITH HEMP DRUGS AND
WITH DHATURA.

Three distinct experiments were conducted in the Biological Laboratory attached to the
Zoological Garden in Calcutta on the effects following the continued administration of hemp
drugs and of dhatura to monkeys.

In the first of them a monkey (Macacus rhesus) was subjected to frequent inhalations of the
smoke of ganja during a period of many months; in the second, two monkeys (M. cynomolgus)
were treated with almost daily doses of charas for more than two months; and in the third
a second specimen of M. rhesus was caused to inhale the smoke of the seeds and leaves of
dhatura periodically during a period of about six weeks.

I regret that no experiment on the effects following inhalation of smoke derived from a
mixture of ganja and dhatura was carried out. On learning that the Hemp Drugs Commission
were desirous that such an experiment should be tried, I gave instructions for its immediate
initiation, but as I was obliged to leave Calcutta almost immediately after doing so, my
orders were apparently forgotten, and, on my return to Calcutta in July, I ascertained that
no continuous administration of dhatura had been begun until the receipt of reiterated in-
structions from Europe reached the laboratory in the end of May, and that then dhatura alone
and not a mixture of dhatura and ganja was made use of.

Whilst regretting that the wishes of the Commission have not been fully complied with
in this respect, I do not feel sure that the results of the experiments, conducted as they have
been, are not really more instructive than they would have been had the mixed drugs been
made use of in the third, seeing that, in so far as isolated instances are capable of furnishing
grounds for inference, a comparison of the phenomena present in the first and third experi-
ments appears to indicate that, whilst prolonged, habitual inhalation of the smoke of ganja
alone fails to give rise to any appreciable morbid effects on the cerebral nervous centres, a com-
paratively brief exposure to the influence of habitual inhalation of the smoke of dhatura alone
is accompanied by conspicuous injury to them.

* Not reproduced.

In carrying out the experiments there was no difficulty in securing the administration of
charas so long, at all events, as the animals did not dislike the drug, as it can be mixed
with milk, and the mixture was for some time freely partaken of. In order, however, to secure
efficient inhalation of smoke of ganja or dhatura, it was
necessary to provide a special apparatus, the nature of
which is illustrated in the accompanying photograph.*

It consisted of a chamber which could be hermetically closed at all points, save where
a supply and a discharge tube were connected with its opposite extremities. The walls
of the chamber were composed of wood covered externally by a coating of zinc, and contained
two windows closed with plate glass, one in either of the lateral walls. At one end there
was a sliding door fitting accurately into a brass lined groove. The supply-tube entered
near the bottom of one of the terminal walls and the discharge one emerged towards the top
of the opposite one so as to secure an even diffusion of the smoke throughout the interior of
the chamber as far as possible. The supply-tube was connected distally with a large wash-
bottle, through which the smoke from a chillum of ignited ganja or dhatura passed, and
the discharge one with two large water-aspirators, which served to draw the smoke through
the entire apparatus.

The great difficulty was to secure that no leakage should take place at any of the numer-
ous joints which were present throughout the apparatus, but this was overcome by the liberal
application of cerate and clay, and it then worked most satisfactorily; the only trouble which
was encountered lying in the tendency which the portion of the supply-tube nearest the
wash-bottle had to become choked by resinous matter which had not been completely re-
moved from the smoke during its passage through the water.

The following notes indicate the details of procedure and results in the individual ex-
periments.

                                            EXPERIMENT I.

            On the effects of the systematic inhalation of the smoke of ganja.

Nature of the animal employed: Macacus rhesus weighing 16 lbs.

The first inhalation was administered on the 7th of November 1893 and the last on the
12th of July 1894, so that the experiment extended over more than eight months. During this