THE MICROSCOPE AND MICROSCOPIC METHODS 41 



Aniline-water staining solutions do not keep well, and need to 

 be freshly prepared about every two weeks. The applications 

 of the aniline-water stains will be given under separate headings7 

 In general, however, they are employed where a stain of unusual 

 power is required. 



Carbol-fuchsin. The intensity of staining may also be in- 

 creased by the presence of carbolic acid. The most common 

 example of this is carbol-fuchsin. 



Saturated alcoholic solution of fuchsin 10 c.c. 



5 per cent aqueous solution carbolic acid 100 c.c. 



This solution keeps for some months. It is employed especi- 

 ally where very intense action is required, as in staining spores, 

 flagella, and acid-proof bacteria. 



Loffler's Methylene Blue. A very useful solution, which 

 keeps well, isLoffler's alkaline methylene blue: 



Saturated alcoholic solution of methylene blue. . 30 c.c. 

 1-10,000 aqueous solution of potassium hydroxide 100 c.c. 



This solution stains more intensely than simple methylene blue, 

 and also gives rise to useful differential staining in smears and 

 even in sections of tissue. 



Nocht-Romanowsky Stain. This requires two solutions, one 

 of ripened alkaline methylene blue, the other of eosin. 



Solution i. 



Methylene blue i . o gram. 



Sodium carbonate 0.5 gram. 



Distilled water 100.0 grams. 



Heat at 60 C. for two days until solution shows a slight purplish 

 color. 



Solution 2. 



Eosin, yellowish, water soluble i .o gram. 



Distilled water 100.0 c.c. 



In staining, a few drops of each of these solutions are mixed with 

 about 10 c.c. of distilled water in an Esmarch dish, and the smear, 



