1888.] MICKOSCOPICAL JOUENAL. 47 



ANILIN DYES. 



The following list of anilin colors, though not by any means an extensive 

 one, includes all that I have found really useful in histological w^ork. It is to 

 be regretted that many biologists appear to have lost sight of the true object 

 of histological research in their zeal to discover new staining fluids and pro- 

 cesses, and the number of these now recommended is somewhat appalling. 

 Endeavors to advance any art or science are indeed always praisewortlw, and 

 deserve every encouragement ; but I must confess that it seems to me the 

 science of histology is retarded in its progress by first one and then another 

 ' rushing into print' with descriptions of new processes which have no points 

 of superiority whatever over many existing methods, and are, in fact, much 

 inferior to others. 



It will be seen that several of the colors enumerated are soluble both in 

 water and alcohol ; as a general rule the aqueous stain is the most useful. 

 Eosin is not an anilin dye ; but it is convenient to describe its properties along 

 with the anilins. 



Soluble in water. Soluble hi alcohol. 



China blue — rosanilin. China blue — gentian-violet. 



Bismarck brown. Malachite green. 



Malachite green. Iodine green. 



Safranine. Anilin blue-black. 



Magenta. . Rosein. 



Anilin blue-black. Pure opal blue. 



Methyl-anilin. Eosin. 



China bhte., in a ixo aqueous solution, is a useful stain for tissues injected 

 with carmine, with which it contrasts more strongly and pleasantly than log- 

 wood. Dr. Heneage Gibbes has found it suitable for stomach and spinal- 

 cord. 



Bismarck broxvn. — This is a useful color for gland tissue, and may be used 

 in combination with eosin, rosein, or anilin blue in double-staining. 



jMalachite green. — A fine rich color, and useful in combination with car- 

 mine in double-staining vegetable sections. 



Safranine. — I have found this color useful for staining nuclei in vegetable 

 sections. A i% solution is a useful strength, and the sections must be well 

 washed after staining; clear in oil of cloves, and mount in balsam. 



Magenta. — A ^^% solution is useful for staining fresh tissues. 



Anilin blue-black. — Of all stains this is, perhaps, one of the best for brain 

 and spinal pord. Dissolve a little of the color in water, and add sufhcient 

 strong methvlated spirit to make a yV,°o solution. Mount the preparations in 

 Canada balsam. 



Methyl-anilin. — The peculiarity of this stain is that, in contact with cer- 

 tain tissues, it decomposes into two shades of violet, red and blue; the latter 

 acts upon the nuclei, while the former colors the formed material. In amy- 

 loid degeneration the red violet acts upon the diseased parts, while the blue 

 violet colors the unaffected tissues. Mount the sections either in potassic 

 acetate or in glycerin. 



Iodine green. — This is one of the most useful of the anilin colors, especially 

 in double-staining. It has been recommended for almost every kind of tissue, 

 and to enumerate the different ways in which it has been employed would be 

 no little task. I shall refer to this color, and other anilin dyes, under the head 

 of double-staining. 



Rosein. — A useful color in multiple-staining. I have found this stain su- 

 perior to all others for staining vegetable tissues which have been treated with 



