METHOD OF STAINING SPECIMENS. 35 



XV. Capsule Stain of Hiss. 

 Use the following, heated until it steams : 

 Sat. alcoholic solution of | ,- 



gentian violet or fuchsin j 

 Distilled water .... 95 c.c. 

 Wash in 20 per cent, solution of cupric sulphate crystals. 



XVI. Capsule Stain of Welch. 



(1) Pour glacial acetic acid on film. After a few seconds 

 replace with anilin-water gentian violet without washing in 

 water. (2) Remove all acid by several additions of stain, and 

 allow it to act for three to four minutes. (3) Wash and ex- 

 amine in salt solution 0.8-2.0 per cent. 



CHAPTER Y. 



GENERAL METHOD OF STAINING SPECIMENS. 



Cover-Glass Preparations. The material is evenly spread in 

 as thin a layer as possible upon a cover-glass ; then, to spread 

 it still more finely, a second cover-glass is pressed down upon 

 the first and the two slid apart. This also secures two speci- 

 mens. Before they can be stained they must be perfectly dry, 

 otherwise deformities will arise in the structure. 



Drying the Specimen. The cover-glass can be set aside to dry, 

 or held in the fingers over the Bunsen burner (the fingers prevent- 

 ing too great a degree of heat). Since most of the specimens 

 contain a certain amount of albumenoid material, it is best in 

 all cases to "fix" it, i. e., to coagulate the albumen. This is 

 accomplished by passing the cover-glass (after the specimen is 

 dry) three times through the flame of the burner, about three 

 seconds being consumed in doing so, the glass being held in a 

 small forceps, smeared side up. 



The best forceps for grasping cover-glasses is a bent one, bent 

 again upward, near the ends. (Fig. 11.) It prevents the flame 

 or ^taining-fluid from reaching the fingers. 



