S1AINING IN TISSUES. 293 



STAINING IN TISSUES. Though always present in 

 the diseased tissues, considerable trouble is usually ex- 

 perienced in demonstrating the bacteria by staining 

 methods. The difficulty lies in the fact that the bacilli 

 are very easily decolorized, and in tissues stained by 

 the ordinary processes are robbed of their color even by 

 the alcohol with which the tissue is rinsed out and de- 

 hydrated. If we will remember not to employ concen- 

 trated stainings, and not to expose the sections to the 

 stainings for too long a time, but little treatment with 

 decolorizing agents is necessary, and very satisfactory 

 preparations will be obtained. A number of good 

 methods have been suggested for staining the glanders 

 bacilli in tissues, and if what has been said will be borne 

 in mind no difficulty should be experienced. 



Two satisfactory methods that we have used for this 

 purpose, though perhaps no better than some of the 

 others, are as follows : 



(a) Transfer the sections from alcohol to distilled 

 water. This lessens the violence with which the stain- 

 ing subsequently takes hold of the tissues, by diminish- 

 ing the activity of the diffusion that would occur if 

 they were placed from alcohol into watery solutions of 

 the dyes. Transfer from distilled water to the slide, 

 absorb all water with blotting-paper, and stain with 

 two or three drops of 



Carbolic fuchsin 10 c.c. 



Distilled water ....... 100 c.c. 



for thirty minutes ; absorb all superfluous staining with 

 blotting-paper, and wash the section three times with 

 0.3 per cent, acetic acid, not allowing the acid to act for 

 more than ten seconds each time. Remove all acid from 

 the section by carefully washing in distilled water ; ab- 



