BLOOD EXAMINATION. 79 



point, where the temperature averages between 110" and 

 120°C, and are allowed to remain for 2 hours. 



A more rapid method of fixation is to place the films for 

 1 minute in a solution made by taking 1 part of forma- 

 lin, 9 parts water and 90 parts of alcohol. This method 

 produces almost as satisfactory results as are obtained 

 by heat fixation. 



Staining of the Films, (a) For general purposes 

 Ehrlich's triple stain is perhaps the best. It stains the 

 red corpuscles orange, the eosinophile granules red, 

 the neutrophile granules violet, nuclei of red corpuscles 

 (when present) greenish black, nuclei of leucocytes 

 greenish blue, the nuclei of the lymphocytes being, as 

 a rule, stained less deeply than the others. In using 

 this stain care must be taken not to shake it up. The 

 stain is best withdrawn on a glass rod and the films 

 covered for 6 to 8 minutes, then carefully washed in 

 water, dried and mounted in Canada balsam. 



(6) Eosin and Loefiler's methylene blue. 



Place the films in eosin 2 minutes, then wash and 

 dry. Place in methylene blue for ^ to 1 minute, wash 

 dry and mount in Canada balsam. 



The red corpuscles and eosinophile granules are 

 stained red, nuclei blue, malarial parasites blue. 



(c) Ehrlich's eosin-haematoxylin stain. 



The films are placed in this stain for 24 hours, ex- 

 posed to light, and are then washed, dried and mounted. 



The red corpuscles and eosinophile granules are 

 stained red, nuclei of red discs and lymphocytes, black, 

 nuclei of other white cells, bluish black. 



