THE MICROSCOPE AND MICROSCOPIC METHODS 43 



Solution A. — To a i per cent solution of medicinally pure 

 methylene blue in distilled water add 0.5 per cent sodium car- 

 bonate and heat at 65° C. for 12 hours, then allow it to stand 10 

 days at room temperature. , 



Solution B. — Eosin extra B. A. (Griibler) o.i per cent solution 

 in distilled water. 



Mix Solutions A and B in equal amounts and allow to stand 

 six to twelve hours, stirring at intervals. Filter and wash the 

 precipitate thoroughly. Collect, dry and powder it. 0.15 gram 

 is dissolved in 100 c.c. of pure methyl alcohol to form the staining 

 solution. It keeps perfectly for at least five months. To stain, 

 cover the dried but unfixed film of blood with the staining solu- 

 tion. After 30 to 60 seconds add about an equal amount of 

 distilled water. Allow this mixture to act for five minutes. 

 Wash in distilled water for about one minute, examining the 

 specimen mounted in water under the microscope. Blot, dry 

 thoroughly, mount in balsam, or preserve the specimen as an 

 unmounted film. 



Numerous imitations or modifications of Leishman's stain 

 have been described. 



Giemsa's Stain. — This stain contains certain of the essential 

 constituents of polychrome methylene blue and eosin, the whole 

 being dissolved in a mixture of glycerin and methyl alcohol. 

 Giemsa's Azur I is the substance methylene azure and his Azur 

 II is this substance mixed with an equal amount of methylene 

 blue. His Azur Il-eosin is the compound precipitated when 

 aqueous solutions of Azur II and eosin are mixed. The Giemsa 

 ■solution is made according to the following formula: 



Azur Il-eosin 3.0 grams. 



Azur II 0.8 gram. 



Glycerin 250.0 grams. 



Methyl alcohol 250.0 grams. 



.Dissolve the powdered dyes in the glycerin at 60° C; then add 

 the methyl alcohol previously heated to the same temperature. 

 After mixing, let it stand 24 hours at room temperature, and 



