66 MICRO-ORGANISMS. 



dehydrate in Absolute Alcohol, clear in Cedar Oil and mount 

 in Balsam. 



Kuhne's Methods. 



The sections are transferred from Alcohol to Carbolic 

 Methylene Blue (p. 58), and allowed to remain in this for 

 half an hour (leprosy bacilli require longer 2 hours). 

 The sections are next rinsed in Water, and then placed in 

 Weak Acidulated Water until they are of a pale blue colour 

 (this must be done carefully or too much colour will be 

 removed) ; they are then rinsed in Lithia Water (p. 61), and 

 transferred to a basin of pure Water. The sections are taken 

 up one by one upon the point of a glass needle and dipped 

 into Absolute Alcohol in which some Methylene Blue has been 

 dissolved. They are then transferred to Methylene Blue 

 Aniline Oil to dehydrate, rinsed in Aniline and then placed 

 for about a couple of minutes into some ethereal oil of low 

 density, such as Terebene, to clear, then into Xylol, and 

 mounted in Balsam. 



The above method is one that will apply to the staining of 

 all micro-organisms, with the exception of the bacilli of 

 leprosy and mouse septicaemia ; these it stains insufficiently. 



In order to show satisfactorily the structure of the tissue, 

 Kuhne recommends the following plan : 



After staining in Carbolic Methylene Blue, the sections are 

 decolourised in a diluted solution of Chlorhydrin Blue 

 (p. 62), which requires from 10 to 60 minutes. The sections 

 are then passed through Alcohol, Aniline, Ethereal Oil, and 

 Xylol, and, in order to double-stain, the sections are taken 

 from the Xylol and placed in Safranine Aniline Oil, diluted 

 to about 4 or 5 times its bulk with Aniline. After remain- 

 ing in this from 2 to 10 minutes they are passed again through 

 Ethereal Oil and Xylol before mounting. 



