328 INORGANIC AGENTS 



Prunus Yirginiana. Wild Cherry. (U. S. P.) 



Synonym. — Ecorce de cerisier de Yirginie, Fr.; wild- 

 kirschenrinde, G. 



The bark of the wild cherry, indigenous in the United 

 States, contains a ferment (emulsin) which, in the presence 

 of water, acts on a glucoside (amygdalin, C20 Ho^ N On) con- 

 tjiiued in the bark, with the formation of hydrocyanic acid, 

 glucose and a volatile oil. A fluid extract, infusion and 

 syrup of prunus virginiana are official. The latter prepara- 

 tion is sometimes employed in cough mixtures for dogs, on 

 account of its sedative action. The entire value of the drug 

 depends upon the minute amount of prussic acid formed 

 in it. The official hydrocyanic acid is more reliable, but 

 syrupus pruni virginianse (U. S. P.) maybe used as a vehicle 

 for more efficient remedies. 



Petrolatum. (U. S. P.) 



(Three varieties.) 



1. — Petrolatum Liquidum. Liquid Petrolatum. (U. S. P.) 



Derivation. — A mixture of hydrocarbons, chiefly of the 

 marsh- gas series, obtained by distilling off the lighter and 

 more volatile portions from petroleum, and purifying the 

 residue when it has the desired consistence. 



Properties.— A colorless, or more or less yellowish, oily, 

 transparent liquid, without odor or taste ; or giving off, when 

 heated, a faint odor of petroleum. Spec. gr. about 0.875 — 

 0.945. Insoluble in water ; scarcely soluble in cold or hot 

 alcohol, or cold absolute alcohol ; but soluble in boiling 

 absolute alcohol, and readily soluble in ether, chloroform, 

 carbon disulphide, oil of turpentine, benzin, benzol, and 

 fixed and volatile oils. 



2. — Petrolatum Molle. Soft Petrolatum. (U. S. P.) 



Synonym. — Vaseline, cosmoline. 



Derivation, — A mixture of hydrocarbons, chiefly of the 



