326 On the Extract of Gunjah or Indian Hemp. 



This concentrated solution, still strongly spirituous, was 

 transferred to large Wedgewood-ware capsules, and evapora- 

 ted, at a heat not exceeding 150° Fahrenheit, on a large sand 

 bath with a gentle fire beneath five inches depth of sand, 

 so as to give a steady heat, until all the spirit was dissipated. 

 The resin now floated on the surface of a deep brown colour- 

 ed watery extract, about equal in bulk to it. With the hands 

 well wetted, so as to prevent adhesion, this resin may easily 

 be made into a thin roll, and introduced into a common bot- 

 tle, where it soon settles down into a compact mass, from 

 which any aqueous fluid may be poured off. When the bottle 

 is filled and well corked, it keeps well and retains its smell 

 and colour ; but if the air finds admittance, it becomes darker 

 coloured and its virtue is impaired. 



The aqueous part, when evaporated, yields a brown extract, 

 of about one-tenth of the weight of the resinous matter, 

 which seems not to be materially different from any similar 

 watery extract from an inert dried plant. This conclusion, 

 however, was drawn from its sensible properties only, as no 

 chemical or medical trial was made of it. The alcohol, dis- 

 tilled off from the solution, has a strong smell of the plant, 

 probably owing to the presence of essential oil. 



Badly prepared resinous extract, as made by the process 

 of Dr. O'Shaughnessy, some of which I have seen, is more 

 of a brown than a green colour, and according to a report 

 made to me from the Medical College Hospital, it must be 

 administered in six times the dose to produce the same effect 

 as that procured from the extract made by the method I have 

 indicated. Good resinous extract is soft and adhesive, of 

 a fine deep green, like the colour of the paint named sap- 

 green, when spread thin upon paper, but greenish black in 

 the mass. It has strongly the peculiar smell of the plant. 

 It is very soluble in alcohol, to which it communicates a fine 

 green tint of a shade rather deeper than a grass green. 



In regard to the yield of the plant in resin — Uncommonly 

 good, with many flowering heads, may yield 10 per cent., but 



