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 rain 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. 



