HISTOLOGICAL METHODS 



I. Loffler's Method. 



a. Float section in alcohol. 



b. Remove with section lifter to Loffler's methylene blue from five to thirty 



minutes. 



c. Decolorize in i percent solution of acetic acid for ten seconds. 



d. Dehydrate in absolute alcohol for a few minutes. 



e. Clear in xylol. 



f. Mount in balsam. 



II. Weigert's Method. 



a. Transfer section to alcohol. 



b. Place in lithium carmine five minutes. 



c. Then in acid alcohol fifteen seconds. 



d. Wash in water. 



e. Transfer to slide and dry with blotting paper. 



f. Apply Ehrlich's gentian violet for three minutes. 



g. Blot and place in Gram's solution for two minutes. 

 h. Wash and dehydrate in aniline oil. 



i. Wash with xylol. 



j. Dry, mount in balsam and examine. 



In Loffler's method all the tissues, especially the nuclei and the 

 bacteria, appear blue. 



In Weigert's method, if the bacteria stain by Gram's method, 

 the tissues appear pink, the bacteria a deep blue-black. This lat- 

 ter method is an admirable one. There are many other methods 

 of staining. Paraffine embedding methods may be employed, but 

 for these the student is referred to works solely devoted to technic. 

 The staining methods are the same for paraffine and in experienced 

 hands give better results. 



