EXAMINATION OF BACTERIA WITH THE MICROSCOPE. 3 1 



(e) Wash in water, and examine either in water directly or after 

 drying and mounting in Canada balsam. A modification of this 

 method, sometimes called the Gram-Giinther method, differs 

 from the preceding by using a 3 per cent, solution of hydro- 

 chloric acid in alcohol for ten seconds to hasten decolorization, 

 washing in pure alcohol before and after the acid alcohol. 

 Decolorization is more intense than by the Gram method; 

 the diphtheria bacillus, which is stained by Gram's method, is 

 decolorized by the Gram-Gunther (Kruse). 



Bacteria that are stained by Gram's method: 



Staphylococcus pyogenes aureus, 



Streptococcus pyogenes, 



Micrococcus lanceolatus (of pneumonia), 



Micrococcus tetragenus, 



Bacillus of diphtheria. 



Bacillus of tuberculosis. 



Bacillus of leprosy. 



Bacillus of anthrax, 



Bacillus of tetanus. 



Bacillus aerogenes capsulatus, 



Ray fungus of actinomycosis. 



List of bacteria that are not stained by Gram's method: 



Gonococcus, 



Diplococcus intracellularis meningitidis. 



Micrococcus melitensis. 



Bacillus of chancroids (Ducrey), 



Bacillus of dysentery (Shiga), 



Bacillus of typhoid fever. 



Bacillus coli communis, 



Bacillus pyocyaneus, 



Bacillus of influenza. 



Bacillus of bubonic plague. 



Bacillus of glanders (bacillus mallei). 



