STAINING BLOOD FILMS. 167 
very simple. The film is fixed by heat in the manner 
already described and the stain is poured on to it and 
allowed to act for five minutes. The film is then 
washed, dried with blotting paper and then by gentle 
heat, and mounted in balsam. 
Nuclei are stained green, red blood corpuscles orange, 
and eosinophile granulations bright red. The small 
eosinophile granulations which are present in the poly- 
morphonuclear cells (the neutrophile granulations of 
Ehrlich) are stained violet. The basophile granulations 
are unstained. 
This stain is not suitable for the parasite of malaria, 
nor for bacteria. 
2. Jenner's stain consists of a solution of a compound 
of eosin and methylene blue in methyl alcohol. It must 
be bought ready prepared. Nothing could be more 
simple than the way in which it is used; no preliminary 
fixation is necessary, the film being allowed to dry and 
flooded with the stain. After a period of from a minute 
and a half to three minutes the stain is washed off 
in distilled or vain water and the specimen dried and 
mounted. 
After the use of this stain nuclei are stained blue, red 
corpuscles red, eosinophile granules red, and basophile 
granules violet. A striking feature of this stain, and 
one which distinguishes it from other staining methods 
in which eosin and methylene blue are used is the 
intense way in which the fine eosinophile granules 
in the polymorphonuclear leucocytes take the eosin. 
Observers who have not been familiar with Jenner’s 
stain have mistaken these cells for the eosinophile 
leucocytes; this mistake could not arise after one of 
the latter cells had been seen for comparison, as its 
granules are so much larger and more prominent. 
