224 CLINICAL BACTERIOLOGY AND HEMATOLOGY 



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 polymorphonuclear cells 

 (the neutrophile granulations of Ehrlich) are stained a purplish or 

 coppery colour. 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 by waving the film to and fro in distilled or rain water for a 

 few seconds, and the specimen dried by blotting it between two 

 pieces of clean blotting or filter paper, allowed to get quite dry, 

 and mounted in balsam or cedar-oil, 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. The 

 descriptions of the leucocytes and abnormal red forms, which are 

 appended, are all based on the appearances seen in films stained 

 by this method, from which also Plates VII. and VIII. were drawn. 



Jenner's stain is suitable for a study of the parasite of malaria, 

 which it stains blue. It may be used for the detection of bacteria. 



Leishman's stain is similar in some respects to Jenner's, and is 

 used as follows : The film is flooded with the stain, which is allowed 

 to act for two minutes ; two or three drops of distilled water are 

 then added, and the process allowed to continue for two or three 

 minutes longer. It is then washed, dried, and mounted as above. 

 The colours of films stained by this method differ from those in 



• It has been objected that Jenner's method does not always give good 

 results, and that the above is an insufficient account of the process. Provided 

 that the stain is good (Grubler's can always be relied on, and will keep for 

 several months after being opened, if kept well corked), the method described 

 will always succeed if well-spread films are used. This is essential. But even 

 with bad films (and very bad ones are sent me at times) the results are always 

 sufficiently good to allow a differential leucocyte count to be made. 



