23 



Note III. The longer a film is washed the more 

 blue comes out of the red cells which eventually 

 become pink, but at the same time the red chromatin 

 stain of the nuclei of parasites, etc., is also partly 

 dissolved. Blue may be extracted more readily by 

 using dilute spirit. A film that has been washed too 

 much or insufficiently stained can easily be restained 

 (first dissolving off cedar wood oil with xylol). 



2. Leishmarfs Stain. Is the precipitate resulting 

 from the action of a watery solution of alkalised 

 methylene blue on a watery solution of eosin. The 

 precipitate is filtered off, washed and dried. It is then 

 dissolved in pure methyl alcohol. 



(Leishman's stain in ' soloids ' 0-015 grammes, 

 methyl alcohol 10 c.c. ; or the solution may be 

 bought ready made, but its keeping properties are 

 doubtful.) 



To Stain. (a) Without fixing, with a pipette, 

 cover the film with the solution for one minute. 



(b) Add about twice the quantity of water and 

 mix carefully on the slide (with the pipette). Allow 

 to stain five to ten minutes or for hours. 

 (c) Wash in water. 



3. Giemsa Stain.- From the alkalised solution of 

 methylene blue, Giemsa prepares in a pure condition 

 some of the derivatives, e.g., methylene azure (Azur I). 

 An impure form of this, consisting of methylene azure 

 and methylene blue in equal parts, he calls Azur II, 

 and in fact it is this body that he uses in his stain, as the 

 presence of methylene blue is necessary in order to 

 stain the cell body. Further, he mixes with this an 

 impure substance, Azur II-Eosin which is the 

 precipitate got by the action of eosin on alkalised 

 methylene blue and which, therefore, consists of 

 Azur I-Eosin, methylene blue-Eosin,with some methy- 



