THE MICROSCOPE AND' MICROSCOPIC METHODS 6 1 



(g) Wash in water. 

 (h) Alcohol. 

 (i) Xylol. 

 (j) Balsam. 



Nuclear stains, which may be used as contrast-stains for 

 sections : 



Delapield's Hematoxylin 



Hematoxylin crystals 4 grams. 



~ Alcohol 25 c.c. 



Ammonia alum 50 grams. 



Water : 400 c.c. 



Glycerin loo c.c. 



Methyl alcohol 100 c.c. 



Dissolve the hematoxylin in the alcohol, and the ammonia 

 alum in the water. Mix the two solutions. Let the mixture 

 stand four or five days uncovered; it should have become a deep 

 purple. Filter and add the glycerin and the methyl alcohol. 

 After it has become dark enough, filter again. Keep it a month 

 or longer before using; the solution improves with age. At the 

 time of using, filter and dilute with water as desired. 



Lithium-carmine (Orth) 



Carmine 2.5 grams. 



Saturated watery solution of lithium carbonate.. . . loo.o c.c. 



Add a few crystals of thymol. The carmine dissolves readily 

 in the lithium carbonate solution. Filter the stain at the time of 

 using. Sections are to be left in the stain five to twenty minutes. 



Sections stained in carmine are placed directly in acid alco- 

 hol ( I part hydrochloric acid, 100 parts 70 per cent alcohol) for 

 five to ten minutes. They acquire a brilliant scarlet color. 

 When used as a contrast-strain for tissues containing bacteria, 

 it is best to use it before staining the bacteria, which might be 

 decolorized by the acid alcohol. 



