THE MICROSCOPE AND MICROSCOPIC METHODS 5 1 



spread into a smear between two slides. The smears are then 

 dried and stained in the usual way. Instead of using albumen 

 to fix the sediment to the slide, it is convenient to save some 

 of the original sputum and mix it with the sediment for this 

 purpose. 



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

 glass preparations which may be prepared in the usual way from 

 material supposed to contain spores. 



(o) After drying the smear on the cover-glass, fix it with heat' 

 by passing through the flame three times. 



(b) Float the cover-glass face downward on the surface of 

 steaming hot carbol-fuchsin or aniline-water fuchsin for three to 

 five minutes. 



(c) Wash in 3 per cent hydrochloric acid alcohol one minute, 

 or less. 



(d) Wash in water. 



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

 minute. 



(/■) Wash. 



(g) Dry. 



(h) Balsam. 



The spores are intensely stained by the fuchsin. The stain 

 is removed Jrom'everything except the spores by the acid alcohol. 

 The methylene-blue solution stains the bodies of the bacteria, 

 the spores remaining brilliant red. There are various other 

 methods for staining spores, but this procedure usually gives 

 good results. The principle is the same as in staining the tubercle 

 bacillus, except that more pains are needed to impregnate spores 

 with the dye. 



When it fails, the cover-glass preparation may be treated by 

 Moeller's method previous to staining. After fixation, the prep- 

 aration is immersed in chloroform for 2 minutes, drained and 

 dried in the air. It is then immersed in 5 per cent chromiq 

 acid for 2 minutes, washed thoroughly in water, and stained 

 as above described. 



