76 PHARMACY 



a small amount of alcohol, the remainder of the solvent 

 being white wine. They have no definite strength. 



IV. — Preparations Having as a Solvent Diluted 

 Acetic Acid. 



Acetum, 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. — Preparations Made by Solution and Evaporation. 



Extracfumf 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. 



Extractum Fluidum, pi. Extracta Fluida.— Fluid extracts 

 are permanent, concentrated medicinal solutions of uniform 

 strength. M.l of the fluid extract is equivalent to gr.l of 

 the crude drug. This result is obtained by percolation 

 (usually with alcohol) and partial evaporation. 



VI.— Preparations Made by Distillation or Occurring 

 Naturally, as Exudations from Trees. 



Oleo-Resina, pi. Oleo-Resince. — Oleo-Resins are officially 

 extracts obtained by percolation of the crude drug with 

 ether, and evaporation of the solvent. They have no uniform 

 strength. 



PuJvis, pi. Pvlveres. — 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 

 volatile, deliquescent or irritating are otherwise administered. 

 Powders are used to advantage in veterinary practice, since 

 they are often taken voluntarily on food. 



Trituration pi. Triturationes. — Triturates are combina- 



