290 YETEEINAEY TOXICOLOGY 



The extraction of the poisons of this group depends upon 

 the fact that they are all soluble in an excess of ?ilcohol, 

 to which a dilute acid (sulphuric or tartaric) is added in 

 quantity sufficient to impart a distinct acidity. Acidification 

 is necessary, because some alkaloids are very sparingly 

 soluble in alcohol, but give salts which are more easily 

 dissolved — e.g., morphine. Since the organic acid salts of 

 the alkaloids are more soluble in alcohol than the mineral 

 acid salts, the use of tartaric acid is on the whole preferable 

 to that of sulphuric. When the material is acid, no further 

 addition is necessary. 



A convenient amount of the material in as fine a state of 

 division as possible is mixed with a large amount of 

 alcohol. If 8 ounces of material is to be extracted, one 

 uses about 400 c.c. of alcohol. The reaction to litmus is 

 observed, and if not acid, sufficient tartaric acid is added 

 to secure a distinctly acid reaction. In almost all cases 

 the alcoholic mixture may be warmed nearly to boiling 

 on a water-bath. Physostigmine, apomorphine, and taxine 

 solutions should not be warmed, and in that case the mass 

 should be allowed to stand twenty-four hours. 



When cold, the material is filtered. The alcoholic filtrate 

 contains any of the above specified poisons, and large 

 quantities of such organic substances as fats, oils, carbo- 

 hydrates, the simpler proteins, and bases derived from the 

 decomposition of animal albumins. The residue may con- 

 tain such toxines as ricine, and is rejected, since separate 

 special search for these needs to be made. 



The clear yellow to dark brown filtrate is now concen- 

 trated. This is best done by boiling in a vacuum, whereby 

 the alcohol may be rapidly removed at a temperature of 

 30° to 40° C. A very thick, dark-coloured watery residue, 

 amounting to about 10 to 20 c.c, and generally containing 

 fat, remains. 



The gradual addition of alcohol to this residue usually 

 brings about a precipitation of impurities, such as dex- 

 trine and carbohydrates. This is removed by filtration, 

 and the clear alcoholic solution again evaporated in a 



