Wiish in the ammonium sulphate of iron solution until the 



black clouds cease to be given off; the section should 



now have a bluish-gray color. 



I 



Eiuse in distilled water. 



4 



Dehydrate. 



I 



Clear in oil of bergamot. 



v 

 Pass through xylol. 



V 



Mount in balsam. 



In sections stained in iron-lack-hsetnatoxylin, the 

 details of the nuclear structure, as also the accessory 

 nucleus, are very clearly brought out. 



Weigert's Haematoxylin Solution. 



This is used for staining the central nervous system. 

 The tissues need to be hardened in Miiller's fluid, are then 

 transferred without washing into alcohol, and embedded 

 in celloidin. Thecelloidin block is placed in the following 

 solution for 24 to 48 hours : 



Acetate of copper (saturated aqueous solution) ) 1 



Distilled water . . j- equal pa 



The block is then washed in 70% alcohol for 24 hours, 

 and may then be sectioned. (If desired the sections may 

 first be cut, and then placed in the above solution of acetate 

 of copper for 24 hours, and washed for several hours in 70% 

 alcohol.) Sections are now stained in Weigert's hsema- 

 toxylin solution. 



Haematoxylin crystals, 1 grm. 



Absolute alcohol, . . . . . . 10 c. c. 



Lithium carbonate, 1.2 grms. 



Distilled water, 100 c. c. 



The hsematoxylin crystals are dissolved in the abso- 

 lute alcohol, the lithium carbonate in the water; mix the 

 two solutions. The sections remain in the stain 12 to 24 



