1887.] P. Bruhl— On the Resin of Cannabis indica. 22 5 



2. A description of the commoner Uredines occurring in the neigh- 

 bourhood of Simla (Western Himalayas). By A. Barclay. M. B. Bengal 

 Medical Service. 



These papers will be published in full in the Journal Part II. 



3. On the Besi?i of Cannabis indica. — By P. Bruhl, Esq : Bajshahye 

 College. 



First Paper. 

 Preliminary Experiments. 



Resins, bitter principles, and colouring matters form those groups 

 of naturally occurring compounds the knowledge of which is yet in a 

 rather rudimentary and therefore unsatisfactory state. Chemists have 

 not yet discovered the key to the secret of the constitution of most 

 of those compounds ; and as long as this key is not found, an investiga- 

 tion of them must be destitute of that attraction which attaches itself 

 to experiments on those groups of compounds which can be made the 

 subject of a well-planned series of experiments. For there being com- 

 paratively little to guide the experimenter in his researches, the latter 

 must be of a more or less tentative character, and the time and labour 

 spent in such researches are not uufrequently disproportionate to the 

 results obtained. As, however, resins as well as bitter principles and 

 colouring matter are of considerable interest to the student of vegetable 

 physiology, a thorough investigation of these somewhat heterogeneous 

 groups of compounds is highly desirable ; and India, as a tropical 

 country, might be expected to offer a fair field to the investigator. 



Among the Indian resins about which comparatively little is known 

 to the chemist, the resin of Cannabis indica deserves to be specially 

 mentioned. When we remember the peculiar intoxicating effects of 

 ganja and the valuable medicinal properties of the extract and tincture 

 of Cannabis indica, we should feel rather astonished at the scantiness 

 of the information one can obtain from books and periodicals with 

 reference to the ingredients and active principles of ganja, churrus, 

 and bhang, if it were not for the high price of these substances, which 

 makes a full investigation of them a rather expensive business. 



The following is an account, interspersed with a few historical 

 notes, of a number of qualitative experiments chiefly undertaken with 

 the object of obtaining some data which might come of use in a more 

 extensive series of experiments on Cannabis indica. 



Preparation. — A method of preparing the resin from ganja has 

 been devised by T. and H. Smith. The subject was also taken up by 

 G. Martins, who in the year 1855 wrote a dissertation entitled : * Studien 

 iiber den Hanf.' He prepared the resin from the Extractum Cannabis 



