MICROSCOPIC STUDY AND STAINIXC, 12? 



all these, stains depend upon a combination of eosin and methylene- 

 blue, these elements staining not only as units, but acting together 

 in combination. One and the same solution, therefore, contains a* 

 least three elements which color the various structures of the 

 preparation selectively. 



JENNER'S METHOD. 32 This stain, because of its simplicity, is use- 

 ful for routine use. It is made up as follows : Equal parts of eosin 

 (Gruebler, "W. G. ") one and two-tenths per cent aqueous solution, 

 and methylene-blue (medicinal, Gruebler) one per cent aqueous 

 solution, are mixed and allowed to stand for twenty-four hours. 

 A coarse granular precipitate is formed which appears dark, with 

 a metallic luster on its surface. This is separated by filtration and 

 washed with distilled water until the filtrate appears almost clear. 



To make up the stain 0.5 gram of the dry precipitate is dissolved 

 in 100 c.c. of methyl alcohol. 



In using the stain, preparations are not fixed, but simply dried 

 in the air and immersed in the stain for one to two minutes. After 

 this, wash in distilled water and examine. 



WRIGHT'S MODIFICATION OF LEISHMAN'S METHOD. 33 A one per 

 cent solution of methylene-blue (Gruebler) in five-tenths per cent 

 solution of sodium bicarbonate in distilled water is steamed in a 

 sterilizer at 100 C. for one hour. After this has cooled, a one-tenth 

 per cent aqueous solution of eosin (Gruebler, W. G.) is added until 

 a metallic scum appears on the surface of the mixture. (About five 

 parts of eosin solution to one of methylene-blue is necessary.) The 

 precipitate which forms is collected by filtration, dried, and a 

 saturated solution then made in methyl alcohol. This is filtered 

 and diluted with one-quarter its bulk of methyl alcohol. 



To stain, cover the dried preparation with the stain for one to 

 one and one-half minutes. Dilute by dropping upon the stain dis- 

 tilled water from a pipette until a metallic film appears upon the 

 top. Leave this on for three to fifteen minutes. Wash in distilled 

 water. 



GIEMSA'S METHOD. S * The method of Giemsa is really a modifica- 

 tion of the Komanowsky method. It is widely applicable, being of 

 great value in the staining of the Spirochaste pallida, Vincent's 



32 Jenner, Lancet, i, 1889. 



33 Wright, Jour. Med. Kesearch, ii, 1902. 



, Cent. f. Bakt., I, xxxvii, 1904. 



