16 ORIENTAL PLAGUE chap. 



(a) Methylene blue and eosine, and 



(b) Dilute alcoholic fuchsin. 



As to (a): a mixture is made according to Czinzinski's 

 formula. It is this : — 



Concentrated aqueous solution of methylene blue, Griibler, 50 cc. 

 Eosine (soluble in alcohol) . . . . 0*5 gram. 



Absolute alcohol . . . . 70 cc. 



Distilled water . . . . . 130 cc. 



This stain, if correctly made and properly used, is 

 far preferable to any double stain that I know ; it is 

 most useful for tissues (film specimens, as also sections 

 of hardened tissues) not only containing bacteria or fungi, 

 but for all histological and pathological purposes. Nuclei 

 of cells, certain granules and bacteria assume a deep- 

 blue colour ; cell substances, eosinophyle granules, red 

 blood corpuscles appear bright pink. 



Film specimens are fixed, as usual, in the flame, then 

 placed in absolute alcohol for about half a minute, dried, 

 and placed, film downwards, over the stain contained in a 

 watch-glass ; here they are heated, the watch-glass being 

 held by forceps high over a small flame till the dye shows 

 distinct steaming. Wash well in tap water, then in 

 distilled water, dry, and mount in balsam. The plague 

 bacilli appear deep blue (blue black) and distinctly 

 bipolarly stained, the red blood corpuscles are pink, the 

 nuclei of leucocytes and other cells more or less deep blue. 



Sections are placed first in absolute alcohol for several 

 minutes, are then kept in the cold stain for several (six to 

 twelve) hours, are then well washed in water, and passed 

 in the usual manner through absolute alcohol, xylol, and 

 finally mounted in balsam. In these sections the contrast 



