[ 149 ] 



Staining tbe ZTnbcrcIe Bacillna in Sectioned' 



SHERIDAN Delepine {Med. Chron., 1896, v. 17) gives the 

 following notes from the Pathological Laboratory at Owen's 

 College : — The tubercle bacillus can easily be stained in 

 section by the methods recommended originally by Ehrlich and 

 by Ziehl. Many slight modifications in technical details have been 

 introduced by a large number of workers, but the essential step by 

 which the Bacillus tuberculosis can be differentiated from other 

 bacilli consists in tbe use of mineral acids, such as nitric or sul- 

 phuric acid. When bacilli have been well stained with methyl- 

 violet or with fuchsin, it is found that certain dilutions of sulphuric 

 acid and nitric acid will rapidly remove the stain from all the 

 known pathogenic bacilli, with the exception of the bacilli of 

 tuberculosis and" of leprosy, which are discoloured very much 

 more slowly. 



The use of nitric acid is, however, objectionable when one has 

 to deal with delicate tissues, and even sulphuric acid, diluted with 

 six parts of water, will cause a certain amount of distortion. For 

 this reason bacteriologists have long wished to find a method which 

 would be less brutal than those just alluded to. 



Not long before his death. Dr. Kiihne, of Wiesbaden, commu- 

 nicated to Dr. Borrel, of Montpelier, a method in which the use of 

 strong acids was done away with. Dr. Borrel, after using this 

 method in some researches in tuberculous lesion, has strongly 

 recommended it in the Annales de V Institute Pasteur (Vol. VII., 



P- 593)- 



In this method, after the sections have been stained in the 

 usual way by means of carbolised fuchsin, they are placed for a 

 short time in a solution of hydrochlorate of aniline, and after this 

 they are left in alcohol till quite decolourised, when it is found that 

 though the fuchsin has been removed from all the tissues, the 

 tubercle bacilli remain deeply stained. This method, therefore, 

 resembles very closely the Gram's method, with the difference that, 

 instead of Gram's iodine solution being used to fix the stain in the 

 bacilli, in this case it is Kiihne's hydrochlorate of aniline which is 



used. 



*From Pediatrics i July, 1896, p. 38. 



International Journal of Microscopy and Natural Science. 

 Third Series. Vol. VII. l 



