254 BOTANICAL MICROTECHNIQUE. 



For staining sections which would be injured by warming, 

 the methylene blue may be allowed to act for a longer 

 time. The staining fluid is then washed off with water, and 

 the preparation is transferred to balsam, either by being first 

 allowed to dry ( 23), or by the use of aniline between water 

 and xylol ( 24). Many Bacteria, such as the anthrax Ba- 

 cillus, endure treatment with alcohol very well, and may 

 therefore be transferred to balsam in the ordinary way. 



2. Ziel's Carbol-fuchsin. 



468. Ziel's solution of carbol-fuchsin is prepared by rub- 

 bing up one gram of fuchsin with 100 ccm. of a %% aqueous 

 solution of carbolic acid, with the gradual addition of 10 

 ccm. of alcohol. It is very stable. 



With cover-glass preparations, it is allowed to act only 

 about a minute. Under some circumstances its action may 

 be hastened by warming. The preparations may be washed 

 in water and mounted, after drying, in Canada balsam. But 

 strongly stained objects will endure longer washing with 

 alcohol, and may be transferred to xylol, and then to 

 Canada balsam. 



Carbol-fuchsin seems less adapted to use with sections. 



3. Ehrlich's Aniline-water Solutions. 



469. These solutions are prepared by adding 1 1 ccm. of a 

 concentrated alcoholic solution of fuchsin, gentian violet, or 

 methyl violet to 100 ccm. of aniline-water. Turbidity arises 

 at first in this mixture, which prevents its immediate use. 

 But it may be used for staining in 24 hours, after previous 

 filtering. It remains fit for use but a few weeks. 



It is sufficient to let these solutions act for a minute, 

 while heated, on cover-glass preparations. The dye is then 

 washed off with water, and the preparation is dried and 

 mounted in balsam. 



Better staining of the Bacteria contained in sections is 

 obtained by Gram's method, described in the next paragraph. 



