272 Mr. Warington on the Action of Animal Charcoal. 



nux vomica, which had been made on a cold solution and 

 simply filtering it through the charcoal ; it was now digested 

 with the aid of heat, and the whole of its bitter flavour quickly 

 disappeared. The statement of Duflos and Hirsch, on this 

 point, is not therefore entirely correct. 



To try the extent to which this abstracting power proceeds, 

 2 grains of disulphate of quina were dissolved in 2 ounces 

 of distilled water, and animal charcoal gradually added in 

 small quantities to the warm solution until the whole of its 

 bitter flavour was removed; it was found that VI grains of the 

 charcoal had been required to effect this. 



It becomes a matter of surprise that this power of animal 

 charcoal has, as far as I am aware, never been observed be- 

 fore, notwithstanding the frequent and extensive employment 

 which is made of this agent in the preparation of the vegetable 

 alkalies, their salts, and a great variety of other substances of 

 an organic nature, for which it is directed to be used for the 

 purposes of discoloration in all our chemical works and phar- 

 macopoeias. Numerous analyses of organic substances, in 

 which it has been employed, will also be open to error on the 

 same grounds. 



Before leaving this branch of the subject, I should refer to 

 a paper, and 1 believe the only one that bears particularly on 

 any of thq previous statements, by Dr. Louis Hopffi in the 

 17th volume of the Journal de Pharmacie, p. 172, " On the 

 property of Charcoal in destroying the bitter flavour of many 

 bodies;" in which he gives a series of comparative trials with 

 wood and animal charcoal at a temperature between 78° and 

 86° Fahr. on solutions of a specified strength, of the extracts 

 of bitter herbs, woods, roots, barks, leaves, flowers and fruits. 



I annex a few examples from this paper of substances which 

 have formed the subject of experiment in the present commu- 

 nication, as I believe that the great discrepancies which will 

 be noticed arise from the charcoal employed by Dr. Hopff' 

 not having been well prepared. 



In a note the author says that the bitter of nux vomica dis- 



