On the Extract of Gunjah or Indian Hemp. 32J 



indifferent parcels not much more than half of this. An 

 average yield, from upwards of thirty pounds of extract which 

 I have made, may be from six to seven pounds of extract 

 from a bazaar maund of hemp ; to exhaust which quantity, 

 about forty gallons of rum of a strength above London proof, 

 were required. 



The process I have mentioned is a tedious though a good 

 one. With a maund and a half of hemp, one week was 

 occupied in distilling rum through the cask ; two days in 

 distilling the alcoholic fluid ; and four, in the subsequent 

 evaporation in capsules. A quicker procedure, unless by 

 a vacuum apparatus, would give a product of inferior quality. 



In the process given, the hemp is never exposed to a heat 

 even approaching the boiling point of water. In Dr. O^Shaugh- 

 nessy^s process, as detailed in the Bengal Pharmacopoeia, 

 either from oversight or neglect of the now well understood 

 principle of organic pharmacy, to make all extracts, especially 

 when the substance is possessed of great activity, at as low a 

 heat as possible, it is directed that the hemp shall be boiled 

 thrice, for half an hour each time, in u strong spirit/ 5 The 

 process as originally conducted by him in the Medical College 

 was still more objectionable in this respect, as the boiling was 

 made in a Papin's digester, under augmented heat and pres- 

 sure. Hence may have originated the bad quality of the 

 extract first sent to London, and the consequent prejudice 

 against it on the part of many medical men. The extract 

 made according to the directions given in the Bengal Phar- 

 macopoeia, will not only be much inferior in quality to that 

 made by this other process, but more than four times the 

 quantity of spirit will be expended in making it. 



That such a prejudice against this preparation does exist, in 

 Edinburgh at least, is distinctly stated in a letter received 

 from a scientific correspondent there — " This medicine was 

 brought into some disrepute, I believe, with medical men 

 here, in consequence of Dr. O'Shaughnessy's description being 



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