TECHXIC (BLOOD AND BLOOD-FORMIXG ORGANS). 229 



of a concentrated aqueous solution of methylene-blue. To this 5 vols. of 

 water, are added, and the whole allowed to stand for a few days, after 

 which the solution is filtered. This mixture stains in five minutes, and 

 the specimen is then washed with water, etc . The neutrophile granules 

 are colored green, the eosinophile granules red and the hemoglobin 

 yellow. 



Neutrophile and eosinophile granules may also be stained in 

 Ehrlich's neutrophile mixture : 



Orange G, saturated aqueous solution, . . 130 to 135 c.c. 

 Acid fuchsin, " " " . . 80 to 120 



Methyl-green, " " " . . 125 



Distilled water, 300 



Absolute alcohol, 200 



Glycerin, loo 



Mix the above quantities of orange G, acid fuchsin, water, and alco- 

 hol in a bottle and add slowly, while shaking the bottle, the methyl-green 

 and finally the glycerin. The cover-glass preparations should be fixed in 

 the ether and alcohol solution for about one hour, or fixed with dry heat 

 at a temperature of uoC. for from fifteen to thirty minutes. Float 

 the preparation on a small quantity of the stain for about fifteen minutes, 

 wash in water, dry and mount in balsam. The red blood-cells are stained 

 a reddish -brown color (brick-color), all nuclei a light blue-green, the 

 eosinophile granules a fuchsin-red, and the neutrophile granules a violet- 

 red. Griibler, of Leipzig, has prepared a dry powder, known as the 

 Ehrlich-Biondi-Heidenhain three-color mixture, which is prepared for 

 use by making a 0.4% solution in distilled water, to 100 c.c. of which 

 are added 7 c.c. of a 0.5% aqueous solution of acid fuchsin. 



Wright's Method of Staining Blood Films. This excellent and 

 rapid method is especially recommended. 



Stain. Make a one-half per cent, aqueous solution of sodium bicar- 

 bonate in an Erlenmeyer flask and add to it one per cent, of methylene- 

 blue. Steam for one hour in an Arnold steam sterilizer and allow 

 mixture to cool, and when it is cold pour in a large dish. To 100 c.c. 

 of this solution add about 500 c.c. of a one-tenth per cent, aqueous 

 solution of eosin (Griibler's yellowish eosin, soluble in water). The 

 quantity of the eosin solution can not be definitely given ; it is added 

 while constantly stirring until the solution becomes of purple color and 

 a yellowish scum with metallic luster forms on the surface and a finely 

 granular black precipitate appears in suspension. The precipitate is col- 

 lected on a filter and allowed to dry thoroughly. Make a saturated solu- 

 tion in pure methylic alcohol (0.3 gm. of precipitate to 100 c.c. of 

 methylic alcohol) and filter. To 80 c.c. of the filtrate 20 c.c. of meth- 

 ylic alcohol is added to complete the stain. 



Staining of Blood Films. Allow blood film to dry in the air and 

 pour as much of the stain on the cover-glass or slide as it will hold, 

 allowing it to remain in contact with the preparation for about one 

 minute ; then add, drop by drop, enough water to make the stain semi- 

 transparent, and a reddish tinge appears at the borders and a metallic 

 scum on the surface. This diluted stain remains on the preparation two 

 or three minutes. The preparation is now washed in distilled water 

 until the better parts have a yellowish or reddish color. Dry quickly 

 between filter-papers and mount on balsam. Red cells are orange or 



