On the Extract of Gunjah or Indian Hemp. 325 



A coupling screw had been previously firmly attached to a 

 hole in the bottom of the cask, so as to be completely spirit- 

 tight. To this was screwed a coiled flexible metal-pipe 

 of half an inch bore, to act as a condensing and cooling 

 worm, and this was immersed in a vessel of water. The end 

 of the pipe terminated in a large carboy, the neck of which 

 was stopped, but not too closely. 



The pipe or nose of a twenty gallon still, charged with 

 rum, was then inserted into a hole, made to fit it, within 

 two inches of the top of the cask, and luted very tight. This 

 was necessary, as there was a considerable pressure of the 

 alcoholic vapour, particularly in the upper part of the cask. 



The contents of the still were then made to boil until the 

 spirituous part was exhausted, as ascertained by a stop-cock 

 in the top of the still. The water was then run out of the 

 still, a fresh charge of rum introduced, and the same pro- 

 cedure again repeated. 



Alcoholic vapour from the rum was thus caused to act on 

 the hemp, to condense among it, and to extract its resin 

 in the most advantageous manner. The solution issued 

 at first from the worm of a deep green colour, and of the con- 

 sistence of honey ; towards the end of the process it became 

 fluid and brown coloured. The passage of the spirit was 

 continued until no appreciable quantity of resin could be 

 detected in the liquid issuing from the worm. The re- 

 mainder of spirit in the exhausted hemp was expelled from 

 it as far as possible by the slow percolation of water down 

 through the cask. 



The resinous solution obtained was again put into the clean 

 still, and as much of the spirit was recovered by a slow 

 distillation as it was judged could be done without endanger- 

 ing the quality of the extract. The quantity recovered 

 was about one-half of that used, the rest being dissipated 

 through the fissures of the apparatus, retained in the resi- 

 duum, or purposely allowed to remain in the concentrated 

 alcoholic solution. 



