48 . MANUAL OF BACTERIOLOGY 



that the solution may not be completely saturated. The purpose of the above 

 procedures is to modify the methylene-blue so that other staining elements are 

 developed in it (polychromism) . The modified methylene-blue solution is 

 then combined with eosin. For further details see Wright. Journal of Medical 

 Research. Vol. VII., 1902. 



Beside the various modifications of the Romanowsky stain given above, a, 

 number have been recommended, all of them having this in common that the 

 nuclear stain depends upon the modification of methylene-blue due to the 

 action of dilute alkali. Giemsa has put on the market a ready prepared stain 

 which is essentially a modified Romanowsky. The trade name for the prep- 

 aration is "Asur I. (pur.)". "Asur II" is a mixture of Asur I with equal 

 parts of methylene-blue. 



Staining of Spores. — The method is applicable to cover- 

 glass preparations which may be prepared in the usual way 

 from material containing spores. 



(ff) After drying the smear on the cover-glass, and fixation 

 with heat by passing through the flame three times, use aniline- 

 water fuchsin or carbol-fuchsin as a stain. 



(6) Heat until the preparation begins to boil; remove for a 

 minute; heat again, and again remove; repeat this process six 

 times. 



(c) Wash in dilute alcohol (Novy) or in a weak solution of 

 acetic or hydrochloric acid for a few seconds to a minute. 

 Some spores are quickly decolorized by i per cent, acetic acid; 

 others may keep the stain when subjected to 3 per cent, 

 hydrochloric acid alcohol for a minute. 



{d) Wash in water. 



(e) Stain with watery solution of methylene-blue half a 

 minute. 



(/) Wash. 



ig) Dry. 



Qi) Balsam. 



The spores are intensely stained by the fuchsin. The stain 

 is removed from everything except the spores by the acid. 

 The methylene-blue solution stains the bodies of the bacteria 

 the spores remaining brilliant red. There are various other 



