Mr. A. Christison on Cannabis indica. 483 
panied by its operculum, can be considered as complete, and 
every figure of the species wanting this important part must be 
equally imperfect ; therefore it is much to be regretted that in 
several expensive modern works on Conchology, their artists and 
authors have neglected to figure the operculum of the. species 
they have drawn; and especially as many of the specimens 
figured in Mr. Reeve’s work, for example, have been taken from 
specimens in the Museum, or Mr. Cuming’s collection, which had 
their operculum affixed on the shells, the absence of the oper- 
culum renders the excellent and characteristic figures contained 
in that work much less valuable than they otherwise would have 
been. I may add, the opercula were formerly supposed to be con- 
fined to the Gasteropodous Mollusca. They are well developed 
in the heteropodous genera Atlanta and Oxygyrus, the one being 
annular and the other spiral; and in the genus Limacina (or 
Spirialis) among the Pteropodous Mollusca. Some have sup- 
posed that the fossil Cephalopodous family Ammonites are pro- 
vided with one, as an operculum-like body is often found in the 
cavity of these shells. 
XLIV.—On Cannabis indica, Indian Hemp. By ALEXANDER 
Curistison, F.B.S.E , Member of the Royal Medical Society *. 
Tue object of the present communication is to give some account of 
the Indian Hemp, a substance which has been long used in the Indian 
and Persian empires as a medicinal and intoxicating agent, but which 
was unknown to Europeans, except through the reports of travellers, 
until of late years. It was first brought into prominent notice by 
Dr. O’Shaughnessy of Calcutta in the year 1839. 
It would be beyond the scope of this paper to enter minutely into 
the early history of the plant, but it may be observed that the nar- 
cotic properties of Cannabis indica were unknown to the Greek phy- 
sicians. In the year 600 the Hindoos were in the habit of employing 
it, since which time it has been in constant use as a means of allaying 
pain, and more particularly as an intoxicating drug, among the inha- 
bitants of the East. Hemp would seem to have been known at a still 
earlier period to the Chinese ; in a communication to the Académie 
des Sciences in the early part of this year by M. Stanislas Julien, ex- 
tracts are given from a Chinese work. showing that so far back as 
A.D, 220, a Chinese physician named Howshoa produced insensibility 
in his patients by means of a preparation of hemp, and that opera- 
tions were then performed without pain to the patients. The veracity 
of this statement may however safely be questioned. 
Until the year 1839 the properties of Hemp were never investigated 
in this country, but the essay of Dr. O’Shaughnessy published at that 
time attracted attention to the subject, and many experiments with 
* Read before the Botanical Society of Edinburgh, April 11, 1850, 
ol* 
