54 



by allowing the raw drug to macerate in water. Usually 

 a hot infusion is made by pouring boiling water over the 

 material and allowing it to cool gradually. 



3. Percolation — a method of extraction in which the solvent 



(menstruum) gravitates through the powdered material. 

 The solution passing through is called the percolate. 



When the solvent is alcohol rather than water, the 

 resulting solution is called a tincture. Tinctures may be 

 made by maceration, and by percolation. The percolate, 

 concentrated so that one cubic centimeter is equivalent 

 to one gram of the dried drug, is known as afluidextract. 

 When a percolate is evaporated to a solid or semi-solid, 

 the resulting product is called an extract. 



4. Distillation — a process of evaporation followed by condensa- 



tion. Volatile oils are collected in this way. 



5. Special methods, used in purifying the active principles. The 



chemical and physical nature of the compound deter- 

 mines the method applied. 



In conclusion I wish to acknowledge thanks to my father, 

 Charles Bausor, for many suggestions in the preparation of this 

 paper. 



Columbia University 

 New York City 



