74 PHARMA.CY 



and societies, schools of pharmacy and pharmaceutical asso- 

 ciations, with the collaboration of medical officers from the 

 army, navy and marine hospital service. The last edition 

 dates from January 1st, 1894 All matter occurring in the 

 "Pharmacopoeia " is said to be according to the U. S. P., or 

 official. That occurring in the " British Pharmacopoeia " ia 

 marked B. P. 



Official Preparations. 



L^Preparations Whose Solvent is Water. 



Decocturriy pi. Decoda, — Decoctions are solutions of crude 

 drugs in water, obtained by boiling. Unless specified 

 otherwise, their strength is 5 per cent., and the boiling is 

 conducted fifteen minutes. Decoctions tend to undergo 

 rapid decomposition, and are only suitable in case of those 

 drugs whose active principle is soluble in water. They are 

 unsuitable when the active principle of a drug is volatile, 

 decomposed by heat, or whea it contains much starch, which 

 would form an easily decomposable, thick mass. 



Drugs containing hard, woody substances, especially 

 albumin, which coagulates in boiling and remains in the 

 crude drug, are those especially adapted for this method. 



InfTisumy pi. Infusa. — Infusions are aqueous solutions of 

 drugs made by maceration in boiling water without the aid 

 of ebullition. Maceration is done for half an hour, and the 

 strength is 5 per cent., unless otherwise ordered. The same 

 disadvantages apply in the case of infusions as with decoc- 

 tions, in addition to the longer time required for their 

 preparation. Some drugs, as digitalis or ergot, which yield 

 their active principles to water and are more powerful when 

 freshly made, are suitable for this process. 



Liquor J pi. Liquores, — Solutions are preparations holding 

 active non-volatile principles in solution in water. They 

 have no uniform strength. 



