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 

 Spinalis) 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 

 Christison, F.B.S.E , Member of the lloyal Medical Society*. 



The 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 Academic 

 des Sciences in the early part of this year by M. Stanislas J ulien, 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, 



31* 



