398 CHAPTEE XXXI. 



Borax ...... 2'0 parts. 



Ferricyanide of potassium . . 2'5 



Water . . .200*0 



They remain in the solution until they are decoloured to 

 the right degree that is, until complete differentiation of 

 the nerves (half an hour to several hours), and are then 

 rinsed with water, dehydrated with alcohol, and mounted in 

 balsam. They may be previously stained, if desired, with 

 alum-carmine for the demonstration of nuclei. 



The results are most splendid. The blue-black nerves 

 stand out with admirable boldness on a golden ground. The 

 method is applicable to the study of peripheral nerves as 

 well as to nerve centres, and is likely to be of utility in 

 Vertebrate embryology. 



Nerve tissue is not the only tissue stained by the process, 

 which can be usefully applied to lymphatic glands and to 

 skin (see SCHTEFFEKDECKER, in Anat. Anz., ii, 1887, p. 680). 



The process is applicable to tissues that have been hardened in alcohol or 

 in any other way, provided that they be put into a solution of a chromic 

 salt until they become brown, before mordanting them in the copper solu- 

 tion. 



It is not necessary that the mordantage be done in bulk. MAX FLESCH 

 (Zeit. f. wiss. MiJc., iii, 1, 1886, p. 50) prefers (following LICHTHEIM) to 

 make the sections first, and, after mordanting, bring them on a spatula into 

 70 per cent, alcohol, and thence into the stain. 



For a method for regenerating the staining solution after use, see FANNY 

 BEELINEEBLAU, Zeit.f. wiss. Mile., 1886, p. 50, or previous editions. 



PANETH (ibid., 1887, p. 213) makes the stain with extract of logwood 

 instead of pure hsematoxylin. 



BEEGLIA (ibid., vii, 2, 1890, p. 236; see also Journ. Roy. Mic. Soc., 1890, 

 p. 817) stains with liquid extract of logwood or Pernambuco wood. 



For both of these see previous editions. 



GEEOTA (Intern. Monatsschr. Anat., xiii, 1896, pp. 138, 139 ; Zeit. f. 

 wiss. Mik., xiii, 3, 1896, p. 315) states that the reaction can be obtained 

 by using the copper after the stain, and that an alum-haematoxylin may be 

 used. He dissolves 6 grm. haematoxylin in 60 of absolute alcohol, and 

 adds 200 of 1 per cent, alum solution, lets the solution stand for ten days, 

 stains therein sections for four to twenty-four hours at 37 C., puts them 

 for 2 hours into the copper acetate at 37 C., and then differentiates. 



711. WEIGEET'S 1891 Method (Deutsche med. Wochenschr., 

 42, 1891, p. 1184; Zeit.f. wiss. Mik., viii, 3, 1891, p. 392). 



