-156— 



hours, are then washed in Weigert's differentiating fluid ; 



Borax, ......... 2 grms. 



Potassium ferricyanide, 2.5 grnis. 



Distilled water, 100 c. c. 



The sections remain in the differentiating fluid until 

 the gray matter has a brownish-yellow, and the white a 

 bluish-black color. . Sections are then washed in tap 

 water for several hours, dehydrated in alcohol, and cleared 

 in the following clearing fluid (Weigert's) : — 



Carbolic acid crystals ... 1 part. 

 Xylol 3 parts. 



The sections may then be mounted in balsam. 

 This method has been variousl}' modified ; two such 

 modifications are here given. 



Pal's Method. 



Prepare and cut sections as for Weigert's stain. Stain 

 in Weigert's hsematoxylin solution, after staining wash the 

 sections in water to which a trace of lithium carbonate has 

 been added. The sections are then placed in a \^Jo aqueous 

 solution of permanganate of potash in which they remain 

 20 to 30 seconds, are then rinsed in distilled water, and 

 differentiated in the, following solution: — 



Oxalic acid 1 grm. 



Potassium sulphite (Kj S03) . . 1 grm. 



Distilled water . . . . 200 c. c. 



Tliey remain in this solution for -^ to 1 minute, or until 

 the gray matter has assumed a yellowish color, are then 

 washed in water, dehydrated, cleared in Weigert's clearing 

 fluid, and mounted in balsam. 



Benda's Method. 



Beudii's moditicaHoii is usiiall\^ followed in tliis laboratory. 

 Harden tissues in Miiller's fluid. 



Embed in celloidin. 



; 



Sections are placed for 12 to 21 hours in the following solution 

 Liquor ferri ter snlphatis . ' 1 part. 



Distilled water .... 2 parts. 



