REAGENTS. 



8oi 



Ziel's Carbol-fuchsin. — This solution is prepared by adding 

 15 c.c. of a concentrated alcoholic solution of fuchsin to 100 c.c. 

 of water containing 5 grams of carbolic acid. 



Aniune Dyes are usually employed in concentrated aqueous 

 solution, but owing to the difference in solubility of the dyes the 

 solutions vary in strength. Saturated solutions of eosin or gentian 

 violet may be prepared by dissolving i gram of the dye in 100 c.c. 



Fig. 321. Reagent bottle for sterile solutions. 



of water, while to make a saturated solution of methylene blue 

 requires 0.400 Gm. of the dye to 100 c.c. of water. Some investi- 

 gators prefer to replace the distilled water with aniline water, 

 which is prepared by adding about 3 grams of anilin oil to 100 

 c.c. of distilled water. 



Reagent Bottle for Sterile Solutions. — The solutions of 

 the aniline dyes as ordinarily prepared deteriorate more or less 

 rapidly and are usually made up fresh each time they are required 

 for use. These solutions, as well as other reagents that are prone 



51 



