SYSTEMATIC AND DESCRIPTIVE. 2QI 



The spores (Fig. 1 10) are not stained by the ordinary 

 methods. The cover-glass preparations must be raised 

 to a high temperature in the incubator, or treated with 

 sulphuric acid (p. 309), or passed about twelve times 

 through the flame of the Bunsen burner, or floated on hot 

 solution of the dye. 



FIG. in. SPORES OF BACILLUS ANTHRACIS, x 1200; stained with gentian 

 violet, after passing the cover-glass twelve times through the flame. 



To double-stain spore-bearing bacilli. Float the cover- 

 glasses for about twenty minutes on hot alcoholic solution 

 of fuchsine. Decolorise in weak hydrochloric acid, and 

 after-stain with methylene blue (Fig. 112). 



Tissue sections are best stained by the method of Gram, 



* *& 



OEEBSI 

 2 r d,_ ; ; 5 .... 



* % '! 



FIG. 1 12. --FROM A DOUBLE-STAINED PREPARATION OF BACILLUS 

 ANTHRACIS, x 1200. 



and after-stained with eosin, picrocarminate of ammonia, 

 or picro-lithium-carmine. 



A more rapid double stain is obtained by immersing the 

 sections in a watery solution of gentian-violet, rinsing in 

 alcohol, and then staining by the method of Orth (p. 61). 



Weigerfs Method. Place the sections for two to five 

 minutes in a I per cent, watery solution of gentian violet 



