APPENDIX TO THE HISTOLOGICAL SECTION. 115 



are required. The best temperature is 20 to 25 C., then rinse in 

 distilled water and transfer to a solution of nitrate of silver, 0*5 to 

 0'7 p - c- , for 24 hours to several days. The rapid process is best for 

 young structures, before the meyline sheath has developed. (S. R. 

 Cajal recommends the addition of formic acid, 1 to 2 drops to 300 cc of 

 the silver solution, when dealing with cerebellum and cerebral cortex 

 which are nearly fully grown.) 



Double impregnation method (S. R. Cajal). After the treatment 

 already mentioned, blot off the silver solution ; the pieces of tissue 

 are placed in bichromate of potassium 6 or 7 g , water 100 cc , osmic 

 acid IP- C -. 30 to 35 cc or less. In this they remain for two days. 

 Blot off the surface fluid, and return to the silver solution for 

 24 hours. 



33. Gold chloride. (Ranvier's boiled gold. Traite technique, page 826.) 

 Gold chloride 1 P- C - solution in distilled water 4 parts, formic acid 1 part ; 

 boil and cool. Place small pieces of tissue in this for 20 minutes 

 or longer. Wash and transfer to formic acid diluted with four 

 volumes of water, and keep in the dark for 24 hours. Dissociate 

 in glycerin. Good for end plates in muscle. 



Lemon juice method. Ranvier, I.e., page 813. Place the tissue in 

 freshly expressed juice (filter through flannel). Transfer to 1 P- C -, 

 5 to 10 minutes, until it has become transparent. Transfer to 1 P- C - 

 gold chloride for 20 minutes, then wash in distilled water ; reduce 

 in 50 cc distilled water with 2 drops of acetic acid, in the dark, for 

 24 hours. 



Tartaric acid method. Stain the tissue in 1 P- C - gold chloride until 

 it is penetrated, one-half to two hours, for cornea, rinse in water ; 

 reduce in nearly saturated solution of tartaric acid kept at 50 C. 

 (embedding bath) until a greyish violet colour is produced : 20 minutes 

 to one hour. 



34. Moppupgro's method for isolating muscle fibres. Virchow 

 Archiv., Vol. 10, p. 540. 



1. Fix in salicylic acid 2'5^- c - in alcohol, renew several times, after 

 a week replace by 



2. Concentrated solution of salicylic acid in ivater, which should 

 gradually replace the alcoholic solution. After all the alcohol has been 

 removed, then 



3. Envelope the pieces in cotton wool, boil in the aq. solution for 

 an hour in a water bath, and let the tissue remain in the cooled fluid 

 for two iveeks. 



