LIST OF REAGENTS. 497 



SOFT PARAFFIN. 



Melting-point about 40 C. 



Use. To smear the sides of the block that is being cut, so as 

 to ensure the sections cohering by their edges into a con- 

 tinuous ribbon. 



VI. CEMENT FOR FIXING DOWN SECTIONS 

 CUT IN PARAFFIN. 



GLYCERIN AND ALBUMEN (Mayer's Albumen). 



Preparation. Mix equal volumes of fresh white of egg and 

 glycerin. Keep a piece of camphor in the bottle. 



Use. For fixing sections in order upon the slide. For full 

 directions see Introduction, p. xxxiii, and p. 465, where 

 directions for staining sections on the slide are also given. 



VII. INJECTION FLUIDS. 



CARMINE INJECTION FLUID. 



Preparation. Rub 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. 

 Rub up the residue with camphor water. 



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

 must be well shaken before use. 



PRUSSIAN 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 ferrocyanide 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. 



