102 POISONOUS PROTEINS 



of water and 1 c.c. of glycerine, allowed to 

 evaporate spontaneously on clean blotting pa- 

 per, leaves no foreign odor when the last trace 

 of the alcohol has disappeared. This is a IT. S. 

 P. test and shows the absence of more than a 

 trace of fusel oil. 



6. A mixture of 10 c.c. of the alcohol and 0.2 

 c.c. of two per cent KOH solution is evapo- 

 rated to 1 c.c. and then treated with an excess 

 of dilute (1:4) sulphuric acid. This should not 

 develop the odor of fusel oil. 



7. 10 c.c. of the alcohol is evaporated to 2 

 c.c. and this is shaken with an equal volume of 

 sulphuric acid. The development of a reddish 

 color shows the presence of amylic alcohol. 



8. When 20 c.c. of the alcohol is shaken in a 

 clean glass stoppered bottle with 1 c.c. of silver 

 nitrate, test solution, the mixture should not 

 become more than faintly opalescent or acquire 

 more than a faint brownish tint when exposed 

 to diffuse daylight for six hours. This is a 

 U. S. P. test for organic impurities, amylic al- 

 cohol, aldehyde, etc. The imported alcohols are 

 not up to standard at all times by this test. 



9. Into a test tube which has been rinsed with 

 the alcohol, pour 5 c.c. of sulphuric acid, then 

 layer the acid with an equal amount of the alco- 

 hol. The appearance of a red zone after stand- 



