Methods for Staining. 



It has long been known that when properly hardened 

 tissues are subjected to the action of coloring matters, cer- 

 tain elements of the tissues, even certain* parts of the cells, 

 show greater affinity for the stain than otffers. This selec- 

 tive action noticed in so many stains, warrants the place 

 they hold in histological technic. Of the great number in 

 use, a few of the most trustworthy, and such as can be 

 most easily made and used, are here given. 



HJEMATOXYLIN SOLUTIONS. 

 Boehmer's Solution. 



This solution is one of the best in use, and is made 

 after the following formula: 



Hsematoxylin crystals * . . .1 grm.) , T 

 Absolute alcohol . . . 10 c. c.j ' 



Potash alum , . . . . . 10 grms .) 1 TT 

 Distilled water '..' . 200 ; c. c.\ . S< 



The crystals of hsematoxylin are dissolved in the abso- 

 lute alcohol, and kept in a well-stoppered bottle for 24 

 hours (solution I). 



The alum is dissolved in warm distilled water, aud al- 

 lowed to cool, keeping it free from dust (solution II). Add 

 solution one to solution two, stir, and keep in an open dish 

 for about a week ; filter, and the solution is ready for use. 



The tissues must be stained in section ; the steps are 

 as follows : 



The tissues may be hardened in Miiller's fluid, alcohol, 

 mercuric chloride, picric acid, nitric acid, etc., are 



