22 PRACTICAL BACTERIOLOGY 



2. Place some Ehrlich's anilin water fuchsin or gentian violet 

 (Ziehl's carbol fuchsin can also be used) in a watch glass or porcelain 

 evaporating dish, float the cover-glass on the surface, material side 

 downwards (if it sinks it does not matter), heat the stain until vapour 

 arises, and set aside one minute to work. 



3. Withdraw the cover-glass with the small forceps, and wash off 

 excess stain with water. 



4. Lay the cover-glass, preparation side upwards, in a watch glass 

 containing 3 per cent. HC1. alcohol (see . 70) for one minute, and 

 move to and fro, when it is decolorized. 



5. Wash with water, and dry. 



6. Stain the cover-glass with a few drops of weak alcohol or watery 

 solution of methylene blue or malachite green for fuchsin stains, and 

 Bismarck brown for the violet stain, being careful not to stain long 

 enough to obliterate any stained Tubercle bacilli. 



7. Wash in water, and dry. 



8. Pass through the Bunsen flame. ' If passed many times through 

 the flame the stained bacteria do not fade so readily. Unna employs 

 this method for Leprosy bacilli.' 



9. Mount in xylol balsam. 



XV. LOFFLEITS METHOD OF STAINING GLANDERS 

 BACILLI IN COVER-GLASS SPECIMENS. 



1. Make a smear preparation from a young nodule, air dry, and 

 fix. 



2. Stain in Loffler's methylene blue solution (see 54) five 

 minutes. 



3. Place the preparation one second in a 1 per cent, solution of 

 acetic acid in water, which is rendered a Rhine wine colour by the 

 addition of a few drops of a watery solution of trapaolin OO. 



4. Wash quickly with distilled water. 



5. Dry, and mount in xylol balsam. 



' The addition of' the trapaolin OO acts as follows: The cell 

 plasma is entirety, and the nuclei partially decolorized 

 while the bacilli retain their colour? 



XVI. METHOD OF STAINING COCCI AND GONOCOCCI 

 IN COVER-GLASS SPECIMENS. 



1. Prepare the cover-glass specimen in the ordinary manner, air dry, 

 and fix. 



2. Flood the specimen with concentrated watery solution of methy- 

 lene blue. 



