250 REPORT OF THE INDIAN HEMP DRUGS COMMISSION, 1893-94. [CH. XII.
The determination of cause depends wholly upon history. The Commission
also consider it not improbable that there are no typical brain lesions peculiar
to hemp drug insanity, though definite lesions are doubtless present in chronic
cases, as they are in cases due to other causes.
In answering the question, therefore, on what the evidence rests that hemp
drugs may induce mental aberration, the Commission would offer the following
remarks: The evidence may be considered under two heads—(a) popular; (b)
scientific. The popular idea that the use of hemp drugs may induce insanity
can be traced back for many centuries, and the present day views on the sub-
ject are no doubt the outcome of old popular ideas which have been handed
down and become concrete. With non-medical witnesses the mere use of the
drug along with the fact of insanity, as the evidence shows, has as a rule been
accepted as cause and effect. Of the large number of medical witnesses who
have given evidence before the Commission, probably not a single one has ever
observed the inception of the habit and the use giving rise to mental aberration,
and been in a position to gauge the value of other contributory causes if present.
With practically no modern literature on the subject, with no special knowledge
apart from the popular idea, with a very slight or no clinical experience of insanity
in England, with the experience derived from perhaps having had half a dozen
insanes in the course of two years under observation as Civil Surgeons, officers
have been placed in charge of asylums, and have had to differentiate between cases
of hemp drug insanity and ordinary mania. The careful inquiry which has been
made by the Commission into all the alleged hemp drugs cases admitted in one
year into asylums in British India demonstrates conclusively that the usual mode
of differentiating between hemp drug insanity and ordinary mania was in the
highest degree uncertain, and therefore fallacious. Even after the inquiry which
has been conducted, it cannot be denied that in some of the cases at least the
connection between hemp drugs and insanity has not been conclusively estab-
lished. But taking these accepted cases as a whole, we have a number of
instances where the hemp drug habit has been so established in relation to the
insanity that, admitting (as we must admit) that hemp drugs as intoxicants
cause more or less of cerebral stimulation, it may be accepted as reasonably
proved, in the absence of evidence of other cause, that hemp drugs do cause
insanity.
The action of hemp resin, the active principle of all forms of the drug, when
taken internally, has formed the subject of accurate experimental observations,
and the physiological action of the drug on the human subject and animals is
fairly well known. When, however, the products of the destructive distillation
of the resin are inhaled, as in ganja smoking, the precise physiological effects
induced have not hitherto been, so far as the Commission are aware, as fully
studied. Dr. Russell's experiments (Bengal witness No. 105) already quoted are,
the Commission understand, the only ones instituted on man with any pretensions
to scientific accuracy. On the other hand, Assistant Surgeon Bocarro (Sind wit-
ness No. 20) and others refer from careful actual observations to the general
physiological effects induced by smoking ganja and charas. With the object
of elucidating the physiological effects of the products of the destructive distilla-
tion of hemp resin, Dr. D. D. Cunningham, F.R.S., Professor of Physiology,
Medical College, Calcutta, at the request of the Commission, kindly undertook a