70 OTHER ANILIN STAINS. 



out for a short time in acidulated alcohol, and then in pure alcohol (followed 

 presumably by clearing and mounting in balsam). Schiefferdecker, whose 

 account is here quoted, says that the results, as regards nuclear figures, are 

 even finer than with safranin. The method is applicable to objects fixed in 

 " Flemming." 



A useful stain for fresh tissues is also obtained by using dilute acetic acid 

 in the manner recommended above (by EHELICH) for Dahlia, 103. 



Amyloid matter appears red in preparations stained with methyl violet. 

 This appears to be an optical effect, see the curious experiments of CAPPARELLI, 

 in Archivio per le scienze mediche, iii, No. 21, p. 1. 



107a. Fuchsin may also be used in GEASEE'S way (last ). 

 See also 104. 



B. Plasmatic stains (stains not affecting nuclei). (This group 

 is put in small type because although the colours of which 

 it consists are stated to be pure plasma stains, they will 

 probably not be found in practice so generally useful, espe- 

 cially for double staining, as many diffuse stains, such as 

 eosin or picric acid.) 



108. Bleu Lumiere is stated to be a plasma stain not affecting nuclei. 

 I have not been able to make out whether it is identical with Parma blue, 

 which is one of the numerous toluidin blues. If it is, Frey recommends a 

 solution in water of 1 : 1000, in which tissues stain in a few minutes, and 

 may be mounted either in glycerin or balsam. " Lichtblau " is possibly a 

 synonym of this colour. The principal use of such a colour is for making 

 double stains. 



109. Bleu de Lyon (Bleu de Nuit, Grunstichblau). I quote this 

 colour here, although I am not sure to what extent it is a pure plasmatic 

 stain. It is said to be very useful for double staining with carmine. 



110. Indulin (Nigrosin, Bengalin, Anilin Blue-black, Blackley 

 blue, Artificial Indigo). (Introduced by Calberla, see Morph. Jahrb., 

 iii, 1877, p. 627). Indulin dissolves into a dark-blue solution in warm 

 water or in dilute alcohol. For staining, the concentrated aqueous solution 

 should be diluted with six volumes of water. Sections will stain in the 

 dilute solution in five to twenty minutes ; they may be washed in water or 

 in alcohol, and examined either in glycerin or oil of cloves. 



The peculiarity of this stain is that it never stains nuclei ; the remaining 

 cell-contents and intercellular substance are stained blue. In its general 

 effects it resembles quinolcin blue, and is exactly the opposite of methyl 

 green. The stroma of tendinous tissue, for instance, stains of a fine blue, 

 the connective tissue that surrounds the bundle, hardly at all, and the 

 tendon-corpuscles of Ranvier remaining perfectly colourless stand out as 

 white stellate figures on a blue ground. 



111. Quinolein Blue (Cyanin, Chinolinblau ; v. Ranvier, Traite, 



