248 PRACTICAL HISTOLOGY [XXXI 



Before use 1 c.c. of (b) is added to each 9 c.c. of (a). 



(3) 5 p.c. aqueous chromogen solution. 



(4) Methyl-violet solution in 75 p.c. alcohol, saturated in 

 the warm, allowed to cool and decanted 100 c.c. Oxalic acid 

 5 p.c. 5 c.c. 



(5) A saturated solution of iodine in 5 p.c. potassium iodide. 



(6) Mixture of equal parts aniline oil and xylol. 

 The sections are placed : 



(a) in the potassium permanganate solution for about 10 

 minutes ; and washed in water ; 



(6) in the chromogen mixture for a hour to 4 hours ; 



(c) in the aqueous chromogen solution for a day or more. 

 (This stage may be omitted ; if it is, the stain is more restricted to 

 neuroglia, but is less complete.) They are then fixed to the 

 slide ; blotted ; 



(d) the methyl-violet mixture is poured over them and run 

 off; blotted; 



(e) the iodine solution is poured over them and run off; 

 blotted ; 



(/) they are washed well in aniline oil and xylol, then in 

 xylol, and mounted. 



Neuroglia stain. (Mallory.) 



Pieces of nervous tissue 2 to 5 mm. thick are placed for 4 or 

 more days in the following fluids in succession : 



(a) 10 p.c. formol ; 



(6) saturated aqueous picric acid ; 



(c) 5 p.c. ammonium bichromate in the warm, renewing the 

 fluid at the end of the first day. 



