1899] MICROSCOPICAL JOURNAL. 3 



tory course, however, it is impossible to try them all and 

 consequently those are described which seem to be the 

 best adapted for general use. 



In addition to the ordinary staining solutions and meth- 

 ods there are special processes for certain species such, for 

 example, as the tubercle bacillus, and still others for, 

 staining certain parts of many bacteria, such as the flagella 

 on motile forms, the spores in spore bearing organisms, 

 and the capsule on certain other species. There is a 

 large number of these special methods which are to be tak- 

 en up in connection with the study of the bacteria requir- 

 ing them. 



Formulce for Staining Solutions. — Methylene-blue, gen- 

 tian-violet, methyl-violet, andfuchsin are the dyes used. 

 lceffler's alkaline methylene-blue. 

 Concentrate alcoholic solution, methylene-blue. . .30 cc. 



Caustic potash 1 per cent solution 1 cc. 



Distilled water lOOcc. 



CARBOL FUCHSIN (ZIEHL's SOLUTION). 



Fuchsin (dry) 1 gram. 



Alcohol (absolute) 10 c c. 



Carbolic acid, 5 per cent solution 100 c c. 



Dissolve the fuchsin in the alcohol, after which add the 

 carbolic acid solution. Instead of using the dry fuchsin 

 and alcohol, 10 c. c. of a saturated alcoholic solution of 

 fuchsin may be used. 



Aqueous Solutions. — The aqueous solutions of methyl- 

 violet, gentian-violet, fuchsin, and the other aniline dyes 

 are prepared by adding 1 c. c. of the saturated alcoholic 

 solution of the desired dye to 20 c. c. of distilled water 

 This will impart a decided color to the liquid so that a 

 pipette full will be barely transparent. 



The true aqueous solutions are made by dissolving the 

 dyes in water, but these are weak and not so effective as 

 those prepared from the alcoholic solutions. These solu- 

 tions deteriorate in a short time. The carbol fuchsin and 



