BLOOD. 



Wright. This is a modification of the method used by Jenner. 

 The method is based upon the fixing and solvent powers of me- 

 thylic alcohol. The essential pigments of the stain are polychrome 

 methylene blue and Griibler's yellow eosin. 



(a) Cover the blood film on the slide or cover glass with as much 

 of the stain as it will hold. Allow this to remain undisturbed for 

 about one minute. By this time the film is fixed upon the slide. 



(b) Now add water, drop by drop, until the surface of the stain 

 assumes a greenish metallic tinge. Allow the stain to remain on the 

 cover slip for two minutes longer. 



(c) Wash in tap water for two minutes or until the smear has 

 acquired a yellowish-pink hue. The water serves to differentiate 

 the stain and wash out the excess of blue. 



(d) Dry the specimen carefully with filter paper and mount in 

 Canada balsam. 



4. Iodine Reaction. The reaction which iodine gives with 

 the finely granular oxyphile cells or polynuclear neutrophiles, is 

 known as iodophilia. The following solution is employed: 



Iodine i gm. 



Potassium iodide 3 " 



Water 100 c.c. 



Gum Arabic 50 gm. 



Place a drop of this mixture upon a slide. Take a fresh blood 

 film on a cover slip and press it, film down, upon this mixture. 

 Squeeze out from under the cover slip the excess of the mixture, 

 so that the remaining film is sufficiently thin to avoid obscuring the 

 corpuscles through too deep a color of the mounting medium. 



In normal blood, all the cells will be tinged a bright yellow: 

 the reds, uniformly; the whites, with a more refractile nucleus. 

 In certain pathological conditions, with this treatment of the blood, 

 reddish-brown granules appear in the cytoplasm of the polynuclear 

 neutrophiles as well as granular masses of a similar tinge outside of 

 the cells. 



[65] 



