Staining • 155 



Gram-negative Gram-positive 



Bacillus proteus vulgaris; Staphylococcus pyogenes albus; 



Bacillus pyocyaneus; Staphylococcus pyogenes aureus; 



Bacillus rhinoscleromatis; Streptococcus pyogenes. 



Bacillus suipestifer; 

 Bacillus suisepticus; 

 Bacillus typhosus (whole group); 

 Diplococcus intracellularis meningitidis; 

 Micrococcus catarrhalis; 

 Micrococcus gonorrhoeae (Neisser) 

 Micrococcus melitensis; 

 Spirillum cholera; asiaticse; 

 Spirillum cholerse gallinarum; 

 Spirillum cholerse nostras; 

 Spirillum metschnikovi; 

 Spirillum tyrogenum; 

 Spirochaete duttoni; 

 Spirochaete obermeieri; 

 Spirochaete refringens; 

 Treponema pallidum; 

 Treponema pertenue. 



Eosin and Methylene-blue (Mallory) make a beautiful contrast 

 tissue stain for routine work, and also demonstrate the presence 

 of most bacteria. The success of the method seems to depend largely 

 upon the quality of the reagents used and a careful study of their 

 effects. Hardening in Zenker's fluid is highly recommended as a 

 preliminary. The details as given by Mallory are as follows: 



1. Stain paraffin sections in a s to lo per cent, aqueous solution of eosin 



from five to twenty minutes or longer; 



2. Wash in water to get rid of the excess of eosin; 



3. Stain in Unna's alkaline methylene-blue solution (methylene-blue i, car- 



bonate of potassium i, water loo), diluted i : lo with water, from one- 

 half to one hour, or use a stronger solution and stain for a few minutes 

 only; 



4. Wash in water. 



5. Differentiate and dehydrate in 95 per cent, alcohol, followed by absolute 



alcohol until the pink color returns in the section; 



6. Clear with xylol; 



7. Mount in xylol balsam. 



The nuclei and micro-organisms will be colored blue, the cyto- 

 plasm, etc., red. 



Zieler* recommends for the staining of the typhoid, glanders and 

 other difficultly stainable bacteria, the following method of demon- 

 stration in the tissues : 



1. Fix and harden in Miiller-formol solution. 

 ParafBn imbedding. 



(Orcein D o.i 



2. Staining overnight in ■{ Officinal sulphuric acid 2 . 



[ 70 per cent, alcohol 100 . 



3. Washing in 70 per cent, alcohol for a short time to remove the excess of 



orcein. 



4. Washing in water. 



5. Staining in polychrome methylene-blue ten minutes to two hours. 



6. Washing in distilled water. 



7. Thorough dififerentiation in glycerin-ether i : 2-5 water until the tissues 



become pale blue. 



* "Centralbl. f. allg. Path. u. path. Anat." Bd. xiv, No. 14, p. 561. 



