72 PHARMACEUTICAL BACTERIOLOGY. 



i. Aniline Water. 



Aniline, 2 c.c. 



Distilled Water, 98 c.c. 



Shake frequently, and finally filter several times through filter paper. 

 It should be perfectly clear. This preparation deteriorates rapidly. Make 

 up small amounts and keep in a dark place. It becomes .worthless, even 

 when observing all precautions, in a few weeks. 



2. Carbolic Acid- Solution. 



Carbolic Acid, 20 c.c. 



Distilled Water, 100 c.c. 



Filter. This mordant is rarely used by itself. 



C. Stains. We give here the more important stains, approximately in 

 the order of preferred use. 



i. Loeffler's Methylene Blue. 



Stock Solution (saturated) Methylene Blue, 30 c.c. 



i : 10,000 Sol. KHO in Dist. Water, 100 c.c. 



Mix, shake, filter. This stain is much used as a general bacterial stain 

 and in the examination of blood, pus, etc. 



2. Aniline Gentian-Violet. 



Aniline Water, 75 c.c. 



Stock Solution Gentian-Violet, 25 c.c. 



Mix, shake, filter. This is an excellent bacterial stain. 



3. Carbol-Fuchsin. 



Stock Solution of Basic Fuchsin, 10 c.c. 



5 per cent. Sol. Carbolic Acid, 100 c.c. 



Mix, shake, filter. This is one of the most useful stains with the so-called 

 acid-proof microbes. It is also a spore stain, and is the most commonly em- 

 ployed stain used in contrast or double staining. It is a comparatively slow 

 stain, but is permanent. 



4. Gram's Stain. 



Gram's stain is used for diagnostic purposes, and is perhaps the best 

 known stain in the entire field of bacteriological technic. Its value depends 

 upon the fact that certain microbes, when stained and afterward treated 



