1901} MICROSCOPICAL JOURNAL. 249 
To fix by heat the simplest method is to draw the speci- 
men three times through an alcohol flame—holding the 
cover slip in a spring forceps. A more accurate method 
is to place it on a metal plate at 110° F. for 20 minutes, 
To fix by alcohol, place the slip in alcohol for from a half 
hour to twenty-four hours. The following mixture will 
also give excellent results: 
Forty-per-cent solution of formaldehyde m. v. Aqua 
destillat m xlv. alcohol gq. s. Immerse the specimen in 
this solution for five minutes. Then stain. 
A. Cover the slip with the eosin solution D (it is only 
necessary to flood the film side of the specimen). Let it 
remain from one-half to one minute and wash by run- 
ning water over the specimen until the water comes away 
~ clear. 
B. Flood slip with methylene blue solution C.. Let it 
remain about two minutes and wash as before. 
6. Dry either as the specimen was first dried, or in 
clean filter paper. 
7. Mount in a half drop of Canada balsam upon a slide, 
placing the film side down in the balsam. Examine with 
the oil immersion lens, dropping a half drop of cedar oil 
on the upper surface of the specimen. 
To use Ehrlich’s stain we proceed exactly as above ex- 
cepting we should write: 
5. Flood the slip with Ehrlich’s tri-acid stain. Let it 
remain from three to five minutes and wash. The wash- 
ing and drying should be done quickly, especially if or- 
dinary hydrant water is used. 
The first method of staining is equivalent to the use of 
Plehn’s solution which is a mixture of eosin and methy- 
lene blue. Staining by eosin and methylene blue causes 
the red corpuscles to appear red, the cytoplasm of some 
leucocytes very faintly blue, while all of the neuclei are 
stained blue. The granules of the eosinophiles stain de- 
cidedly red, and the neuclei are a pale blue. 
