TECHNIC (BLOOD AND BLOOD-FORMING 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 1 20 



Methyl-green, " " " . . 125 



Distilled water, 300 



Absolute alcohol, 200 



Glycerin, 100 



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 noC. 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 



