CHAPTER XXXVI. 549 



xviii, 1901, p. 222) makes the mordant with 20 parts of tannin in 

 80 of water, and 15 parts of 2-5 per cent, chromic acid added 

 gradually. This mordant will keep for months. 



Rossi (Arch, per le Sc. med., xxiv, 1900, p. 297 ; Zeit. wiss. Mik., 

 xviii, 1901, p. 226) takes for the mordant a solution' of 25 grms. of 

 tannic acid in 100 of caustic potash of 0-1 per cent., which will keep 

 indefinitely. The stain is Ziehl's carbol fuchsin, 289. Cover- 

 glasses are prepared with a drop of culture, dried, and treated with 

 1 drop of the mordant and at the same time 4 to 5 of the stain, 

 allowed to remain for fifteen to twenty minutes, washed, and 

 mounted. See also Centralb. Bakt., xxxiii, 1903, p. 572 (Zeit. wiss. 

 Mik., xix, 1903, p. 517). 



GEMELLI (Centralb.,. xxxiu, 1903, p. 316 ; Zeit. wiss. Mik., xix, 

 1903, p. 516) mordants for ten to twenty minutes in 0-025 per cent, 

 permanganate of potash, rinses and stains for fifteen to thirty 

 minutes in a mixture of 20 parts -75 per cent, aqueous solution of 

 calcium chloride and 1 part of 1 per cent, neutral red solution. 



A method of PITPIELD is described by KENDALL, Journ. app. Mic. , 

 v, 1902, p. 1836 (Journ. Roy. Mic. Soc., 1902, p. 502). The mordant 

 consists of 10 parts of 10 per cent, tannin solution, 5 parts of 

 saturated sublimate solution, 5 of saturated solution of alum, and 

 5 of carbol fuchsin. Mordant for a minute with heat, and stain 

 with a mixture of 2 parts saturated aqueous solution of gentian 

 violet with 10 of saturated solution of alum. 



VAN ERMENGEM (Journ., 1894, p. 405) fixes for a few minutes with 

 a mixture oi; 1 part 2 per cent, osmic acid, and 2 parts 10 to 25 per 

 cent, solution of tannin, washes, treats with 0-25 to 0-5 per cent, 

 solution of nitrate of silver, then for a few seconds with a mixture 

 of 5 parts gallic acid, 3 of tannin, 10 of acetate of soda, and 350 of 

 water, then puts back again into the silver for a short time, then 

 washes and mounts. 



See also STEPHENS, ibid., 1898, p. 685, and G-ORDON,i&i, 1899, p. 235, 

 and the methods of TRENKMANN (Centralb., vi, 1889,'p. 433 ; Zeit. wiss. 

 Mik., vii, 1890, p. 79) ; BROWN (Journ. Roy. Mic. Soc., 1893, p. 268) ; 

 JULIEN (ibid., 1894, p. 403) ; SCLAVO (Zeit. wiss. Mik., xiii, 1896, p. 96) ; 

 HESSERT (ibid., p. 96) ; MUIR (Journ. Roy. Mic. Soc., 1899, p. 235) ; 

 MCCRORIE (ibid., 1897, p. 251 ; he stains for two minutes in a mixture 

 of equal parts of concentrated solution of night-blue, 10 per cent, 

 solution of alum, and 10 per cent, solution of tannic acid) ; ZETTNOW 

 (ibid., 1899, pp. 662, 664); MORTON (ibid., 1900, p. 131); WELCKE 

 (ibid., p. 132) ; LEVADITT, C. R. Soc. Biol., lix, 1905, p. 326 (for Spiro- 

 chcete pallida, KAMON'S neuroflbril stain) ; MEIROWSKY, Munch, med. 

 Wochenschr., Ivii, 1910, No. 27 ; KALB, ibid., No. 26 (Zeit. wiss. Mik., 

 xxix, 1912, pp. 123, 124 ; both for Spirochcete). 



