390 OHAPTEK XXX. 



liquid. The sections are then brought into a mixture of 10 

 parts of anilin oil with 90 parts of 96 per cent, alcohol, and 

 are differentiated therein until colour is no longer given off 

 from them. They are got on to a slide, dried with filter- 

 paper, cleared with oil of cajeput, dried again with filter- 

 paper, treated with a few drops of benzin, and mounted in 

 benzin-colophonium . 



Prof. VAN GEHDCHTKN writes me that he prefers to take 

 paraffin sections, mounted on slides by the water method 

 ( 182), and stain them for five or six hours in Nissl's mixture 

 in a stove kept at .35 to 40 C. Differentiation is done as 

 above, and the sections are mounted in xylol-damar. 



In a later paper (op. cit., p. 781 ; Zeit. f. wlss. Mik., xiii, 

 2, 1896, p. 237) NISSL advises .that after covering the sections 

 with a drop of the benzin- colophoiiium they should be passed 

 through a flame. The benzin gases ignite, and must be 

 blown out immediately, and the operation repeated until the 

 medium no longer ignites. This is said to prevent diffusion 

 of the stain after mounting. 



Slight modification by TELJATNIK, Neurol. Centralb., xv, 1896, p. 1129 ; 

 Zeit.f. wiss. Mik., xiv, 1897, p. 79. 



SADOVSKY (C. R. Sue. Biol., iii, 1896, p. 353) stains sections 

 of formol material for a quarter of an hour to several hours 

 in 1 per cent, methylen blue (or for one to three minutes in 

 a concentrated solution of fuchsin in " 5 per cent, carbolic 

 acid water "), then treats them on the slide with 1 per cent, 

 acetic acid until the grey substance is clearly differentiated 

 from the white, dehydrates in absolute alcohol and passes 

 through xylol into balsam. The fuchsin gives the sharper 

 stain. 



GTOTHARD (op. cit.,v, 1898. p. 530; Zeit.f. wis*. Mik., xv, 

 4, 1899, p. 487) stains celloidin sections for twenty- four hours 

 in Umia's polychromatic methylen blue and differentiates in 

 a mixture of 5 parts of creosote, 4 of oil of cajeput, 5 of 

 xylol, and 16 of absolute alcohol. 



LORD (Journ. Meat. Sci.. Oct., 1898; Zeit. f. wiss. Mil-., xvi, 

 1899, p. 59) treats sections of fresh material frozen for a few 

 seconds before staining with a mixture of equal parts of 

 6 per cent, formol and saturated solution of picric acid. He 



