74 PRACTICAL HISTOLOGY. 



in bacteriology, e.f/., for the tubercle bacillus, but largely for double- 

 staining of tissues, in contrast to red. It stains axis cylinders of 

 nerve fibres. (See Nervous System and Epithelial Cement.) 



Sections to be mounted in balsam are best clarified by cedar-oil. 



Better results are obtained by using a very dilute solution made 

 as follows (Garbini) : Add 10 drops of a saturated alcoholic 

 solution to 100 cc. of a solution of caustic potash (i in 10,000). 

 Leave the sections to stain (12-24 hours). Leave them in absolute 

 alcohol (6-8 hours), and then in oil of cloves (2-4 hours) xylol 

 xylol-balsam. 



Spiller's Purple. Use Spiller's purple No. i. Hub up 2 grams 

 in a glass mortar with 10 cc. of alcohol, and add 100 cc. of distilled 

 water. It is used as a double stain, and for staining the fibrin in 

 coagulated blood. The stain requires to be pretty deep, as it is 

 washed out by alcohol. If a section stained by it is to be mounted 

 in balsam, use cedar-oil to clarify it. 



(C.) Green Aniline Colours. Amongst these are iodine green, 

 methyl green (i per cent.), aniline green, and aldehyde green. 



Iodine-Green is used as a 5 per cent, filtered watery solution. 

 It stains nuclei and developing cartilage green, and makes a good 

 contrast stain. It is not very readily extracted by spirit, and does 

 not soon fade. 



Methyl-Green. This is a nuclear stain. Make a i per cent, 

 solution in distilled water, and add 25 cc. of absolute alcohol. 

 Belgian observers, more particularly Carnoy, use this for fresh tissues 

 in the following manner : 



Methyl-green ..... i gram. 

 Glacial acetic acid . . . I cc. 



Distilled water . . . . .100,, 



Add a few drops of this liquid to a watch-glassful of an indifferent 

 fluid, e.g.) normal saline. 



The others will be referred to in the text. 



(D.) Red Aniline Colours. They are very numerous. 



Rosaniline Acetate, Sulphate, and Hydrochlorate (Magenta). 

 The term fachsin is sometimes applied to the one, sometimes to 

 the other, but the acetate is more soluble in water. They give a 

 rather diffuse stain, but <fre useful for nuclear staining, elastic fibres, 

 and blood-corpuscles. 



Rub up a little (i gram) in a glass mortar with rectified spirit 

 (20 cc.). After solution add 20 cc. of distilled water. 



Magenta for Blood-Corpuscles. Dissolve .1 gram of magenta 

 in 5 cc. of rectified spirit and 15 cc. water, and add 20 cc. glycerine. 



Acid Fuchsin is a specific colouring-matter for the nervous 

 system. It was introduced by Weigert, but it has been largely 

 displaced by Weigert's haematoxylin copper stain. 



