426 APPENDIX. 



c. Transfer to 80 per cent, alcohol ^-i hour. 

 ci. Cut sections ; knife and tissue wet with 80 per cent, alcohol. 

 The later method of Weigert directs the preparation of the fol- 

 lowing staining solutions : 



^ / Lithium carbonate (1.2 gm. : 100 c.c. HaO) 7 c.c. 



I Distilled water 100 c.c. 



TJ f Haematoxylin, crystals i gm. 



\ Absolute alcohol 10 c.c. 



e. Stain sections for 12 to 24 hours in mixture composed of 9 

 volumes of A -\- i volume of B. 



f. Wash thoroughly in distilled water. 



g. Transfer to 90 per cent. 15 minutes. 

 h. Transfer to 95 per cent. 15 minutes. 



i. Transfer to anilin oil-xylol (anilin oil 2 vol. -j- xylol i vol.) 5 

 minutes. 



j. Transfer to pure xylol 5 minutes. 



k. Mount in balsam. 



The exact degree of color must be determined by experience and 

 the individual taste of the worker ; the Weigert method in any of 

 its forms is a stain particularly for the medullated nerve-fibres, the 

 cellular elements being better displayed by carmine or other haema- 

 toxylin dyes. 



Cox-Golgi method for displaying the nerve-cells of the central 

 nervous system possesses the advantages of simplicity and relative 

 certainty over the older silver impregnation methods of Golgi. 

 Small pieces of nervous tissue, not over from two to three centi- 

 metres cube, are placed in a mixture composed of- 

 Solution of potassium bichromate (5 per cent. ) 20 c.c. 



Solution of corrosive sublimate (5 per cent. ) 20 c.c. 



Solution of potassium chromate (5 per cent.) ....... 16 c.c. 



Distilled water 44 c.c. 



and allowed to remain until ready for cutting, the fluid being changed 

 after the first, third, and seventh days, and subsequently each week 

 for a month, if necessary. When ready for sectioning, the tissue is 

 transferred directly to 95 per cent, alcohol for two hours and then 

 embedded in celloidin by successive treatment with alcohol-ether, 

 thin and thick celloidin solutions. After cutting, the sections are 

 cleared in a mixture of 



Xylol 3 parts, 



Phenol i part, 



and mounted in balsam ; cover with cover-glass. 



