184 PLASMA STAINS WITH COAL-TAR DYES. 



Lewis wrote. See also HEIDENHAIN in Zeit. wiss. Mik., xx, 1903, p. 185, 

 and xxv, 1909, p. 407. 



330. Violet B (or Methyl Violet B) (S. MAYEK, Sitzb. L L Akad. 

 wiss. Wien, iii, Abth., February, 1882). Used in solutions of 1 grm. 

 of the colour to 300 grms. of 0-5 per cent, salt solution, and with 

 fresh tissues that have not been treated with any reagent whatever, 

 this colour gives a stain so selective of the elements of the vascular 

 system that favourable objects, such as serous membranes, appear 

 as if injected. The preparations do not keep well ; acetate of 

 potash is the least unsatisfactory medium for mounting them in, 

 or a mixture of equal parts of glycerin and saturated solution of 

 picrate of ammonia (Anat. Anz., 1892, p. 221). See also under 

 " Plasmafibrils." 



The allied dye, Crystal Violet, has been employed for staining 

 sections, e.g. by KROMAYER and others. BEND A (N enrol. Centralb., 

 xix, 1900, p. 792) stains in a mixture of 1 vol. saturated sol. of the 

 dye in 70 per cent, alcohol, 1 vol. 1 per cent. sol. of hydrochloric 

 acid in 70 per cent, alcohol, and 2 vols. of anilin water, the liquid 

 being warmed until vapour is given ofT, then cooled and the sections 

 dried with blotting-paper, treated one minute with 30 per cent, 

 acetic acid, dehydrated with alcohol and cleared with xylol. 



331. Kresyl Violet. An oxyazin dye, giving metachromatic stains. 

 HERXHEIMER (Arch. mik. Anat., liii, 1899, p. 519, and liv, p. 289) stains 

 sections of skin with Kresyl-echtviolett. Nuclei blue, plasma reddish. 

 Similarly TICK (Centralb. allg. Path., xiii, 1902, p. 987 ; Zeit. wiss. Mik., 

 xx, 1903, p. 223), staining for three or four minutes in a concentrated 

 aqueous solution, and differentiating in alcohol until the connective 

 tissue lias become colourless. Keratohyalin violet-red to salmon- 

 coloured. 



332. Saureviolett, see 316. 



333. Benzoazurin may be made to give either a diffuse or a nuclear 

 stain, according to MARTIN (see Zeit. wiss. Mik., vi, 1889, p. 193). 



334. RAWITZ' " Inversion " Plasma Stains.- -It has been discovered 

 by KAWITZ that by means of appropriate mordants certain basic anilins, 

 which by the usual methods of regressive staining are pure chromatin 

 stains, may be made to afford a pure plasma stain, thus giving an 



' inversion " of the usual stain. The stain, in my opinion, is a vile one. 

 For details see fourth edition, or RAWITZ (Sitzb. Gesnaturf. Freunde, 

 Berlin, 1894, p. 174 ; Zeit. wiss. Mik., xi, 1895, p. 503 ; and his Leitfaden 

 f. hist. Untersuchungen, Jena, 1895, p. 76). 



335. Artificial Alizarin (RAWITZ, Anat. Anz., xi, 10, 1895, p. 295). 

 A double stain by means of artificial Alizarin, or Alizarin -cyanin, 

 requiring the use of special mordants supplied by the colour manu- 

 facturers, and very complicated. See fifth edition. 



