XV. DOUBLE STAINING OF SECTIONS WITH HE- 

 MATOXYLIN AND PICRIC ACID OR EOSIN. 



(Only for structure staining, or for staining sectiona containing 

 actinomjces or the zoogloea masses of the micrococcus ascoformans 

 found in the so-called "scirrhous cord" of the horse). 



1. Section from alcohol to Friedlander's hematoxy- 

 lini solution, from a half -hour to twenty-four hours, ac- 

 cording to the strength of the solution. 



(It is perhaps best to add to a watch-glass of water or of alum 

 solution (1:250) a sufficient quantity of Friedlander's hematoxylin so- 

 lution to give the mixture a good red-wine color. In this mixture sec- 

 tions are stained, from one to two hours). 



2. Decolorize in 96 per cent, alcohol, and if the sec- 

 tion remains too intensely stained, wash alternately in 1 

 per cent, hydrochloric acid alcohol, and water (or alcohol) 

 V tU the section becomes a delicate bluish-red color. 



If a single hematoxylin stain only is desired the section is now 

 dehydrated in alcohol, cleared in oil, and mounted in balsam. If, 

 however, a double stain is desired, proceed as follows: 



3. DOUBLE STALNLNG WITH PICRIC ACID. 



(a) Transfer the decolorized hematoxylin section to 

 a concentrated alcoholic (96 per cent.) solution of pic- 

 ric acid for a half minute; oil from two to five minutes; 

 balsam; or, 



(b) Transfer the decolorized hematoxylin section 

 from alcohol to a watch-glass containing oil of cloves, to 

 which from 10 to 15 drops of a concentrated alcoholic so- 

 lution of picric acid has been added, five to six minutes; 

 balsam. 



4. DOUBLE STAINING WITH EOSIN. 



(a) Transfer the decolorized hematoxylin section to 

 a watery solution of eosin,^ one minute; dehydrate in 96 

 per cent, alcohol; oU; balsam; or 



(b) Transfer the decolorized hematoxylin section 

 from alcohol to a watch-glass containing oil of cloves, to 

 which eight to ten drops of a concentrated alcoholic solu- 

 tion of eosin has been added ; balsam. 



IFRIEDLANDBR'S HEMATOXYLIN SOLUTION. 

 Hematoxylin. 



Alum aa 2 parte 



Alcohol 



Glycerin 



Aq. dest aa -.100 parts 



2 Add to a watch-glass of water a few drops of a cone. ale. so- 

 lution of eosin until a distinct eosin-redi color is obtained; or mix 

 1 part of cone. ale. eosin solution with 100 parts of water. 



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