176 Animal Micrology 



tain granules of leucocytes and for red blood corpuscles, giving to 

 the latter a very characteristic coppery-red tinge. Some workers 

 prefer to dissolve it in water or in some cases in the clearer. 



41. Erythrosin. An eosin ; properties and manipulation, much 

 the same as ordinary eosin (see 40). 



42. Fuchsin, Acid (Rubin S, Acid Majenta, Majenta S).- 



Acid fuchsin 0.5 grain 



Distilled water 100.0 c.c. 



This is an excellent anilin stain for cytoplasm ic structures. It 

 is also used in some instances as a specific stain for nerve tissue. 

 Acid fuchsin should not be confounded with basic fuchsin which 

 is a nuclear stain. It too is used in aqueous solution. When 

 fuchsin alone is mentioned by writers, without specifying whether 

 it is acid or basic, the basic fuchsin is ordinarily meant. 



43. Fuchsin (Acid) and Picric Acid (Van Gieson's stain ).- 



Acid fuchsin, 1 per cent, aqueous solution . . 10 c.c. 

 Picric acid, saturated aqueous solution ... 90 c.c. 



This stain is frequently used in conjunction with hematoxylin 

 in the study of fibrous or of nerve tissue. Small bits of tissue 

 should be fixed in corrosive sublimate or its mixtures. Sections 

 are slightly overstained with hematoxylin, rinsed in water, and 

 then stained 5 minutes in the picro-fuchsin mixture. To avoid 

 extracting too much of the yellow color in dehydrating and clear- 

 ing, the alcohols and clearer should each have a few crystals of 

 picric acid added to them. The result should be: nuclei and 

 epithelia brown ; white fibrous connective tissue red ; elastic tissue 

 and muscle yellow. 



44. Gentian Violet. This is one of the best of the nuclear 

 anilin stains. It is best made up in anilin water and weak 

 alcohol (see 29). 



Gentian violet 1 gram 



Anilin water 80 c.c. 



Alcohol, 95 per cent 20 c.c. 



The stain works well with thin sections. It is also widely 

 used in the study of bacteria. For differentiation, Gram's 

 method is used. 



