226 CHAPTER XVI. 



colour used by them, so that it is not possible to ascertain whether they 

 mean the Blue-black B of the oxyazo series, or the Anilin black of 

 LIGHTFOOT, also known under the names of Wigranilin and Woir Colin. 

 Dr. GBUBLER writes me that the anilin blue-black of his list is the oxyazo 

 colour blue-black B or AZOSCHWARZ, and that he believes that Nigranilin 

 and Noir Colin are no longer manufactured. 



314. Carmine Blue (Bleu Carmin Aqueux, prepared by Meister, 

 Lucius and Briinig, at H6chst-a-M.). JANSSENS (La Cellule, ix, 1, 1893, 

 p. 9) has shown that this colour possesses a special affinity for the parts of 

 cytoplasm that are undergoing cuticular differentiation. He uses it in 

 alcoholic solution acidified. The stain will bear mounting in balsam. 



315. Violet B (or Methyl violet B) (S. MAYER, Sitzb. d. I: fr. Altad. 



d. wiss. Wien, iii Abth., February, 1882). This colour is a methyl violet 

 prepared by Bindschedler and Busch of Bale, and by the Aktienfabrik fiir 

 Anilinfarben at Berlin. Used in solutions of 1 grm. of the colour to 300 

 grins, of 0'5 per cent, salt solution, and with fresh tissiies 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). 



316. Saureviolett, see 301. 



317. Benzoazurin may be made to give either a diffuse or a nucleai 

 stain, according to MARTIN (see Journ. Roy. Mic. Soc., 1890, p. Hi). 



318. Baumgarten's Fuchsin and Methylen Blue (Zeif. f. wiss. 

 Mi'k., i, 1884, p. 415). Stain sections (of chromic objects) for twenty-four 

 hours in a stain made by adding 8 to 10 drops of concentrated alcoholic 

 solution of fuchsin to a watch-glassful of water. Rinse with alcohol, and 

 stain for four or five minutes in concentrated aqueous solution of methy- 

 len blue, wash out with alcohol for five to ten minutes, and clear with 

 clove oil. Nuclei red, tissues blue, by substitution. 



319. R A \VITZ' "Inversion" Plasma Stains. It lias been discovered 

 by RAWITZ 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 one not affecting 

 chromatin at all, thus giving an " inversion " of the usual stain. The 

 stain, in my opinion, is a vile one. For details of the process sec lust 

 edition, or K \\vrrz (Sitzb. Gcs. natitrf. Freutide, Berlin, 18!>4, p. 17 I ; 

 Zeit. f. wiss. Mile., xi, 4. 1895, p. 503; and his L>'! ((\nlcn f. Itisf. Unter- 

 suchungen, Jena, 1895, p. 76). 



