1887.] P. Briihl— On the Besin of Cannabis indica. 231 



line reaction, was evaporated and ignited in a platinum crucible, when 

 a residue was left. This was dissolved in dilute hydrochloric acid and 

 a drop of this solution was mixed with a drop of platinic chloride on a 

 glass slide, when the characteristic octahedra and three-rayed groups 

 of potassic platinichloride made their appearance under the microscope 

 Hydrochloric acid causes a turbidity in the alkaline solution of the 

 chloro- derivative ; the precipitate proves itself amorphous under the 

 microscope. Precipitates are formed, when aqueous solutions of calcic 

 chloride, magnesic chloride, cupric chloride, silver nitrate, ferric chloride, 

 platinic chloride are added to the aqueous or dilute alcoholic solution of 

 the potassium compound of the chloro- derivative. All these precipitates 

 are soluble in alcohol and are therefore not formed, when alcoholic 

 solutions of the above-mentioned salts are added to an alcoholic solution 

 of the potassium compound. As result of the preceding investigation it 

 may therefore be stated that the resin of Cannabis indica is acted upon 

 by Chlorine, a chloro -derivative being produced, which has decidedly acid 

 properties, forming with most metals amorphous compounds insoluble in 

 water, but soluble in alcohol. 



Bromine also acts on the resin. When alcoholic solutions of the 

 resin and of bromine are mixed and the resulting mixture is poured into 

 water, a sulphur yellow precipitate comes down, which by the aid of 

 the microscope is seen to be granular-amorphous. It dissolves in 

 alcohol, ether, ethyl acetate, and benzene to form yellow or orange- 

 yellow solutions. In the solid state it forms an orange-yellow resinoid 

 substance, hardly soluble in an aqueous solution of caustic potash. 

 When rubbed up with cupric oxide and tested before the blow-pipe, it 

 gives the bromine-reaction. Hence bromine acts on the resin with the 

 formation of a bromo- derivative. 



Action of caustic alkalis. A number of experiments were also 

 performed with a view to study the action on the resin of potassic and 

 sodic hydroxides in aqueous and alcoholic solutions as well as in the 

 solid state, and at different temperatures. The want of sufficient ma- 

 terials, however, have prevented me hitherto from arriving at definite 

 results. 



t The following paper on the subject will contain an account of 

 qualitative and quantitative experiments concerning the products of the 

 action of halogens on the resin as well as the products of the dry distil- 

 lation of the resin per se and with potassic and sodic hydroxides, whilst 

 the constituents of the essential oil of Cannabis indica as well as the 

 colouring matter of ganja will occupy my attention, as soon as time 

 and circumstances permit. 



