12 
method IVright has further simplified. lYright, in his directions for 'a 
preparing the stain, says to add 1 per cent methylene blue to a one- I 
half per cent solution of sodium bicarbonate and steam the mixture i 
in an Arnold steam sterilizer for one hour, which renders the methy- 
lene blue polychromatic. When cold he adds eosin until the color 
changes from blue to purple and a metallic scum forms on the sur- 
face and a black precipitate appears in suspension. The precipitate I 
is collected on a filter, dried, and dissolved in methyl alcohol. i| 
W right gives the following summary for using the stain : 
1. Make films of blood, spread thinly, and allow them to dry in the air. 
2. Cover the preparation with the alcoholic solution of the dye for one minute. 
3. Add to the alcoholic solution of the dye on the preparation sufficient water, 
drop by drop, until the mixture becomes semitranslucent and a yellowish metallic | 
scum forms on the surface. Allow this mixture to remain on the preparation for 
two or three minutes. 
4. Wash in water, preferably in distilled water, until the film has a yellowish 
or pinkish tint in its thinner or better spread portions. 
5. Dry between filter paper and mount in balsam. 
Goldhorn'’s stain {9 ). — Dry the film and fix in pure methyl alcohol » 
fifteen seconds, wash in running water, stain in 0. 1 per cent aqueous 
solution of eosin for thirty seconds, wash in running water, stain one 
minute in Goldhorn’s polychrome methjdene blue, wash in water, dry 
in air, mount in balsam. 
The polychrome methylene blue is made as follows : 
1. Dissolve 2 grams of methylene blue and 4 grams of lithium car- 
bonate in 300 c. c. of warm water. 
2. Heat in porcelain dish in a boiling water bath fifteen minutes. 
3. Pour into a glass-stoppered bottle and set aside for several days. 
4. Render only slightly alkaline by adding 4 to 5 percent acetic acid 
solution. 
With this stain we have obtained beautiful preparations showing 
the chromatin of the ring form of mstivo-autumnal malaria and the 
chromatin of the tertian parasite. W e have also well-stained prepa- 
rations of blood platelets. It is a good stain for the nuclei of animal 
parasites. It shows the chromatin of the segmenting bodies of 
malaria, the chromatin of the crescents, the eosinphilic and neutro- 
philic granules and nuclei of leucocytes. Mast cells and myelocytes 
are well stained. 
Jenner^s stain . — This stain is not so good for trypanosomes as the 
other two. Equal parts of 1 per cent aqueous solutions of eosin and 
methylene blue are mixed and set aside for twenty-four hours. Tlie 
mixture is filtered, the precipitate is washed with water and dried 
and then dissolved in methyl alcohol. In using this stain no previous 
fixing is necessary. After staining one to three minutes the speci- 
men is thoroughly washed until the corpuscles appear pink. Dry in 
the air and mount in balsam. 
The stain can be bought ready for use from dealers, or a powder ' 
