QUESTIONS AND ANSWERS 305 



Emulsion is a milky fluid obtained by mixing an oil or resin with 

 water. The globules of oil or particles of insoluble resin are held 

 in suspension by some gummy substance, usually acacia. MUk is 

 a natural emulsion. 



What are stimulants? Name (a) a cardiac stimulant, (b) a hepatic 

 stimulant, (c) a cerebral stimulant, (d) a diffusible, or gen- 

 eral, stimulant. 

 A stimulant is an agent which increases functional activity. 

 (a) Camphor, (b) podophyllum, (c) opium, (d) alcohol. 



Name the ingredients, giving the proportion of each, found in each of 

 the following mixtures : the A. C. E. mixture, the E. C. 

 mixture. 



A. C. E. = Alcohol 1 part, chloroform 2 parts, and ether 3 parts. 



E.G. = Ether and chloroform, equal parts. 



What is meant by (a) chemical incompatibility, (b) physiologic in- 

 compatibility, (c) pharmaceutical incompatibility? Give 

 ap example of each. 



(a) Chemical incompatibility occurs when drugs are so mixed 

 that an unsuitable alteration in their chemical composition takes 

 place, e.g., calomel with nitrohydrochloric acid forms corrosive 

 sublimate. 



(b) Physiologic incompatibility consists in the union of drugs 

 possessing antagonistic physiological actions; — e.g., atropine and 

 pilocarpine. 



(c) Pharmaceutic incompatibility results in the production of 

 an unsightly mixture due to physical change ; e.g., resinous tinctures 

 and aqueous solutions cause the resins to separate. 



Howr do tinctures differ from spirits? Give examples. 



Tinctures are alcoholic solutions of non-volatile principles (ex- 

 cept Tr. iodine), made usually by maceration and percolation of 

 the crude drug. Examples, belladonna tincture, aconite tincture, 

 etc. 



Spirits are alcoholic solutions of volatile substances. Example, 

 spirits of camphor. 



Describe the preparation of a tincture. Name five official tinctures. 

 The majority of tinctures are made by percolation. This is 

 accomplished by packing the powdered drug in a suitable vessel and 

 depriving it of its soluble constituents by allowing a menstruum, or 

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