LIST OF REAGENTS. 467 



VII. INJECTION FLUIDS. 



CARMINE INJECTION FLUID. 



Preparation. — Eub up carmine in water : add ammonia drop 

 by drop till the carmine is dissolved : .filter : evaporate at 

 a gentle heat, stirring constantly to get rid of the 

 ammonia. Bub up the residue with camphor water. 



Use. — For injecting small animals and parts of animals. It 

 must be well shaken before use. 



PEUSSIAN-BLUE INJECTION FLUID. 



Preparation. — To a weak solution of ferric chloride add a few 

 drops of hydrochloric acid, and then pour in enough of a 

 stronger solution of potassium ferrocyauide to cause com- 

 plete precipitation. The fluid should be deep blue, but 

 transparent, and the precipitate too fine to be seen with 

 the naked eye. 



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, &c., of rabbits and other 

 large animals. It must be used immediately after prepa- 

 ration. (See Introduction, p. xxi.) 



GELATIN INJECTION. 



Preparation. — Soak gelatin in water till thoroughly soft. 

 Pour off the superfluous water : melt, and stir into it car- 

 mine injection fluid, or other insoluble colouring sub- 

 stance, and a few drops of carbolic acid ; or if preferred 

 the gelatin may be soaked in camphor water, and carbolic 

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

 jection is sohd when cold. 



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

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



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