LIST OF KEAGENTS 421 



PRUSSIAN-BLUE INJECTION FLUID. 



Preparation. To a solution of ferric chloride add a few drops 

 of hydrochloric acid and sufficient potassium ferrocyanide 

 to cause complete precipitation. Shake before use. 



PLASTER OF PARIS INJECTION. 



Preparation. Eub up fine plaster of Paris with water, in a 

 mortar, to the consistency of thin cream. Colour to the 

 required tint with carmine injection fluid or with French 

 blue. Strain through fine muslin. 



Use. For injecting blood-vessels, etc., of rabbits and other 

 large animals. It must be used immediately after pre- 

 paration. (See Introduction.) 



GELATINE INJECTION. 



Preparation. Soak gelatine in water till thoroughly soft. Pour 

 off the superfluous water : melt and stir into it carmine 

 injection fluid, or other insoluble colouring substance, 

 and a few drops of carbolic acid ; or if preferred the 

 gelatine may be soaked in camphor-water, and carbolic 

 acid is then unnecessary. Stir till almost cold. The in- 

 jection is solid when cold. 



Use. For injection of specimens of which it is proposed to 

 make sections. It is to be melted, and kept well stirred 

 during injection. If the specimen is large or difficult to 

 inject, the whole operation must be performed in a vessel 

 of water as hot as the hand can bear it. 



WHITE-OF-EGG INJECTION. 



Preparation. Eub up fresh white of egg with carmine injec- 

 tion, or other colouring fluid which will not cause coagula- 

 tion of the albumen. 



Tj S6m ;p or injecting specimens of which sections are to be cut. 

 It is used fresh, and the specimen is then placed in alcohol, 

 or corrosive sublimate, or in hot water. 



GUM INJECTION. 



Preparation. Make a thick mucilage of gum-arabic and cold 



water. 

 Use. Inject cold, previously colouring as desired. Plunge the 



specimen into alcohol, and the injection will solidify. 



