344 PRACTICAL HISTOLOGY. [xxx. 



taining some alcohol and a few drops of a saturated solution of lithium 

 carbonate (6-10 hours). They are then "differentiated" in per cent, solu- 

 tion of permanganate of potash (10-15 seconds), and subsequently in the 

 following mixture : 



Oxalic acid . . . I gram. 



Potassic sulphite , . i ,, 



Distilled water . . 200 cc. 



When the grey and white matter are differentiated, the sections maybe stained 

 in carmine, safranin. or alum -carmine, and mounted in balsam. 



Stages of Pal's Method. 



(1.) Harden in Miiller's fluid. 



(2.) Cut sections and stain in Weigert's hsematoxylin (24-48 hours). 



(3.) Wash in water to which 1-2 per cent, lithium carbonate is added. Thi 

 sections must be deep blue. 



(4.) Differentiate the sections in 0.25 per cent, potassic permanganate solu- 

 tion (20-30 sees. ) till grey matter becomes yellow. 



(5.) Transfer to oxalic acid solution (few sees.). 



(6.) Wash in water, and dehydrate in alcohol, xylol, balsam. 



This method can be done rapidly. Only the nerve-fibres are stained ; the 

 intervening parts may be stained subsequently with picro-carmine. 



21. Vessale's Modification of Weigert's Method. l 



(1.) Harden in Miiller's fluid and afterwards in alcohol. 

 (2.) Stain celloidiu sections (3-5 mins.) in I per cent, hfematoxylin 

 dissolved in warm water. Allow it to cool. The sections 

 become black. 

 (3. ) Place in saturated filtered solution of neutral copper acetate (3-5 



mins.) and then lave in water. 

 (4.) Differentiate in a solution 



Borax ... 2 grams. 



Potassic ferridcyanide . 2.5 ,, 



Water , . . 300 cc. 



Ganglion-cells, glia-cells, and degenerated parts soon become decolorised, 

 only the medullated fibres remain dark-violet. 



(5.) Wash thoroughly in water. They may be stained with alum- 

 carmine as a contrast stain. 



(6 ) Absolute alcohol. Xylol-carbolic acid (3 : i), remove surplus with 

 bibulous paper. Balsam. 



22. Kulschitzky's Method for Medullated Fibres. 2 



(1.) Harden in Miiller's or Erlicki's fluid (1-2 mins.), then wash in 



water (1-2 days). Alcohol. Make sections in celloidin. 

 (2.) Stain (1-3 hours) in his acid haernatoxylin (p. 342). 

 (3.) Differentiate (2-3 hours) in 



Sat. sol. lithium carb. . . 100 cc. 



Ferridcyanide of potash ( i per cent.) 10 ,, 

 (4. ) Wash thoroughly in water. Balsam. 



23. Golgi's Silver Methods 3 (a. ) Slow Method. Small parts of the cord or 



1 Zeit. wiss. Mikros., vii. p. 517, and Archiv. itol. de Biol. t xv. p. 158, 

 1891. 



2 Annt. Anzeig., iv. p. 519, 1890. 



3 Sulla, fina anatomia degli organi centrali del sistema iiervoso, Milano, 1886. 



