276 BACTERIOLOGY. 



more than ten seconds each time. Remove all acid 

 from the section by carefully washing in distilled water ; 

 absorb all water by gentle pressure with blotting-paper, 

 and finally, at very moderate heat, or with a small bel- 

 lows (Kiihne), dry the section completely on the slide. 



When dried clear up in xylol, and mount in xylol 

 balsam. 



(6) The other method is as follows : 



Transfer sections from alcohol to distilled water; 

 from water to the dilute fuchsin solution, and gently 

 warm (about 50° C.) for fifteen to twenty minutes. 

 • Transfer section from the staining solution to the slide, 

 absorb, all superfluous staining with blotting-paper, and 

 then treat them with 1 per cent, acetic acid from one- 

 half to three-quarters of a minute. Remove all trace 

 of acid with distilled water, absorb all water by gentle 

 pressure with blotting-paper, and then treat the sec- 

 tions with absolute alcohol by allowing it to flow over 

 them drop by drop. For small sections three or four 

 drops are sufficient. Under no circumstances should 

 the alcohol be allowed to act for more than one- 

 quarter of a minute. Clear up in xylol and mount in 

 xylol balsam. 



In method 6 the tissues are better preserved than in 

 a, where they were dried. 



Very good preparations are also obtained by the use 

 of Loffler's alkaline methylene-blue, if care be taken 

 not to stain for too long a time or to decolorize with 

 alcohol too energetically. 



No method of contrast-stain for this organism in tis- 

 sues has been devised. 



In properly stained tissues the bacilli will be found 

 most numerous in the centre of the nodules, becoming 



