STAINS. 



These may be divided into Nuclear, Plasmatic, or 

 Specific, according to their power of staining the nuclei, the 

 whole tissue, or certain elements of the tissue only. 



Nuclear Stains. Hsematoxylin, Carmine and Cochineal, 

 Methylene Blue, Methyl Green, Safranine, Vesuvine (Bis- 

 marck Brown), Gentian Violet, Hoffmann's Blue (acidified), 

 and Fuchsine. 



Plasmatic Stains. Picric Acid, Benzopurpurine, Eosine, 

 Erythrosine, Orange, and Acid Fuchsine. 



Specific Stains. Osmic Acid, Chloride of Gold, Nitrate 

 of Silver, Nigrosine, Acid Fuchsine, Congo Eed, Dahlia 

 Violet, Methyl Violet, Iodine, Eose Bengale, Safranine, and 

 Victoria Blue. 



Stains and methods for Micro-Organisms are treated 

 separately. 



NUCLEAR STAINING. 



There is no colouring matter which is a nuclear stain only. 

 All of them have more or less effect upon the ground sub- 

 stance also. The value, therefore, of any dye as a nuclear 

 stain depends upon the comparative affinity which it has for 

 nuclei and ground substance respectively. 



Direct Nuclear Stains are those in which the nuclei are 

 dyed so rapidly, compared with the rest of the tissue, that no 

 particular treatment is necessary to differentiate them. 



Indirect Nuclear Stains are those in which the whole 

 tissue is deeply stained, and the nuclei are differentiated by 

 subsequent removal of the colour from the ground substance. 



