TUBERCLE BACILLI IN TISSUES. 35 



DEMONSTRATION XIII. 



Sections of Tubercular Tissues — Leprosy Tissues — Cultures of 



Tubercle Bacillus from an Inoculated Animal — 



Cultures of Bacillus of Diphtheria. 



Tubercle Bacilli in Tissues. 

 Sections are furnished (in water), from acute miliary 

 Tuberculosis of lung, and also of Tuberculosis of lung 

 of cattle. 



1. Staining in fuchsin solutions. 



(a) Place the sections in carbol-fuchsin or in anilin 

 fuchsin for from 30 minutes to 24 hours, keeping the 

 stain covered in the incubator at 37°C. Better results 

 are obtained by leaving in stain for 24 hours. 



(6) Rinse the sections in water, and then transfer 

 for a few seconds to 33^% nitric acid. 



(c) Wash at once in 70% alcohol till no more red 

 stain comes away. If the section is still red, wash 

 again through the acid and then in the alcohol. 



(d) Rinse in water and place in Loeffler's methylene 

 blue for 1 minute. 



(e) Rinse again in water, dehydrate in absolute alco- 

 hol, clear in xylol and mount on slide in usual manner. 



Sections from paraffin blocks, received into water at 

 48"0, may be fixed on cover glasses and stained as cover 

 glass films in the following manner: 



Float a section on a cover-glass and repoving from 

 water, blot firmly and evenly with several layers of 



