110 PRIISrCIPLES OF VETERINARY SURGERY 



difficulty. Ziehl's carbol-fuchsin is the stain generally used 

 for tubercle bacilli and its formula is as follows : 



Fuchsin Powder i gm. 



Absolute Alcohol lo c.c. 



Carbolic Acid c. p 5 c.c. 



Distilled Water q. s lOO c.c. 



Filter clear. This solution will keep for years. The 

 technique of using it in staining is as follows : 



1. Spread a thin layer of the material on a cover-glass. 



2. Air-dry. 



3. Fix in a flame. 



4. Apply carbol-fuchsin to the cover-glass, and hold 

 over a flame until steam arises. 



5. Pour off the stain. 



6. Dip rapidly into a 10% solution of nitric acid. 



7. Wash freely in 95% alcohol until the specimen on the 

 cover-glass is colorless. 



8. Stain again with a watery solution of methylene-blue 

 for 3 minutes. 



9. Wash in water, dry with filter paper, and mount in 

 Canada balsam. 



10. Add a drop of cedar oil and examine under the one- 

 twelfth lens. 



By this method of staining, the tubercle bacilli, if pres- 

 ent, will appear as short red rods. All other bacteria and 

 tissue-cells will be stained blue. 



There are a few other bacteria that retain the carbol- 

 fuchsin stain after being treated with acid and alcohol, but 

 these are not met with in general work. They are the lep- 

 rosy, smegma, and Lustgarten bacilli. 



Grain's method of staining has the advantage that by its 

 use, certain bacteria are stained a violet color, and other 

 bacteria are not stained at all. Two solutions are necessary 

 in using this stain: (i) Lugol's solution and (2) aniline oil 

 gentian-violet. 



