78 PHABMACY 



a small amount of alcohol, the remainder of the solvent 

 being white wine. Thej have no definite strength. 



IV. — Pbepabations Having as a Solvent Diluted 

 Acetic Acid. 



Aceturrii pi. Aceta. — Vinegars are solutions of the active 

 principles of drugs in acetic acid prepared by maceration 

 and percolation. They are not of uniform strength. 



V. — Pbepabations Made bt Solution and Evapoeation. 



Extractum, pi. Extracta. — Extracts are concentrated 

 preparations of the crude drug. Ordinarily alcoholic solu- 

 tions of the crude drug are obtained by maceration and 

 percolation, and then evaporated to a pasty mass. They 

 are usually stronger, weight for weight, than the crude drug, 

 but are not of uniform strength. 



Fluidextractum, pi. Fluidextracta. — Fluidextracts are 

 permanent, concentrated medicinal solutions of uniform 

 strength. 1 cc. of the fluidextract is equivalent to 1 gm. of 

 the crude drug. This result is obtained by percolation 

 (usually with alcohol) and partial evaporation.* 



VI. — Pbepabations Made by Distillation ob Occubeing 

 Naturally, as Exudations peom Tbees. 



Oleo-Besina, pi. Oleo-Besince. — Oleo-Kesins are officially 

 extracts obtained by percolation of the crude drug with 

 ether, and evaporation of the solvent. They have no uni- 

 form strength. 



Pulvis, pi. Pulveres. — Powders are preparations of finely 

 pulverized drugs. Sugar of milk is frequently added, on 

 account of its hardness, to aid in pulverization and as a 

 diluent. Comparatively tasteless, non-irritating and often 

 insoluble drugs are given in this form. Drugs that are vo- 

 latile, deliquescent or irritating are otherwise administered. 

 Powders are used to advantage in veterinary practice, since 

 they are often taken voluntarily on food. 



Trituratio, pi. Triturationes. — Triturates are combina- 



* The last (eighth) edition of the U. S. Pharmacopaeia directs that 

 many of the fluidcxtracts be assayed so that they will contain a definite 

 prescribed amount of the active principle. 



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