PHABMACEUTIOAL PKEPARATIONS 75 



Distillation. — Is tlie vaporization of a liquid in a 

 retort or a still, by heat, and conduction of the vapor 

 through a cooled tube, where it is condensed and passes 

 into a receiver and is called the distillate. Distillation is 

 used to purify liquids or recover a volatile liquid from a 

 solid, solution or mixture. Where two liquids are mixed 

 that have different points of vaporization and are separated 

 in this way, the process is called rectification. 



Sublimation. — Distillation of a volatile solid. When 

 the product is in a solid form, it is called a sublimate, as 

 iodine, camphor, etc. ; when in flakes, it is called flowers, as 

 sulphur. 



Maceration. — A term used to denote the action of liquids 

 upon drugs at ordinary temperature. 



Digestion. — Same process, with heat raised to 40° C. 



Menstruum. — Any fluid substance used to dissolve a 

 solid body or extract its medicinal principles. 



Exdpient. — Any substance used to give a pill mass 

 proper consistency. 



Exsiccate. — The process of removing all moisture, even 

 the water of crystallization, from a crystal, by the use of heat. 



Desiccate. — To remove all excess of moisture. Heat not 

 usually employed in this process. 



Incineration. — The combustion of a substance for its 

 ashes. 



Beduction is employed to recover a metal in its purity, 

 when in a combined state. 



Pharmaceutical Preparations. 



The " United States Pharmacopoeia " is an authoritative 

 book, including the drugs of most value, with a description 

 of their properties, tests for their purity, and methods for 

 making their preparations. It is revised each decade by a 

 convention of representative delegates from medical schools 



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