COAL-TAR PLASMA STAINS. 225 



light stain it will stain cytoplasm first, and thus works very 

 well with carmine or safranin as a nuclear stain, leaving the 

 chromatin of a perfectly pure red. I find it gives very good 

 differentiations of nerve tissue, and of cartilage (as has 

 already been pointed out by BAUMGAETEN and by JACOBY). 

 The older mode of using it (MAUEICE and SCHULGIN) was to 

 stain in bulk with it after borax-carmine, using a very dilute 

 alcoholic solution. BAUMGARTKN and JACOBY stain sections in 

 a 0'2 per cent, alcoholic solution. I have experimented 

 with safranin as the chromatin stain, and obtained some fair 

 results. But I do not think the combination can be recom- 

 mended. For if you stain first with the blue, the safranin 

 will extract it if allowed to act for more than a short time. 

 And if you stain first with the safranin, the blue will extract 

 it very quickly. 



312. Methyl Blue. Under this title are comprised some 

 other derivatives of the base rosanilin. They are " acid " 

 colours, being mostly salts of triphenylrosanilin- and tri- 

 pheiiyl-pararosanilin-trisulphonic acid. Here belong the dyes 

 sold as Methyl Blue, Cotton Blue, Water Blue (Wasserblau), 

 Methyl Water-Blue, China Blue (Chinablau), Soluble Blue. 



Amongst these Water Blue (Wasserblau) possesses some 

 useful properties. According to MITKOPHANOW (quoted from 

 Zeit. f. wiss Mik., v, 4, 1888, p. 513), used in concentrated 

 aqueous solution it gives a very good double stain with 

 safranin. It is very resistent to alcohol. Using the Wasser- 

 blau first, and then the safranin, I have had some interesting 

 results, and as the process is easy to carry out I think it may 

 be recommended. The Wasserblau must be used first, as if 

 used after the safranin it will destroy the stain in a short 

 time. With chrom-osmium material, twelve to twenty-four 

 hours in the blue, and four or five in the safranin, may not 

 be too much. My stains have not kept well. 



MANN (op. cit., xi, 4, 1894, p. 490) has used it in conjunction with eosin 

 for staining ganglion cells. For the somewhat complicated details of the 

 process, see the place quoted. 



313. Anilin Blue-black A preparation cited under this name has 

 been recommended by BEVAN LEWIS and others for nervous tissue. Unfor- 

 tunately these authors have not given the chemical description of the 



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