xm STAINING OF CAPSULE OF PNEUMOCOCCUS 55 



(c) Allow the agar-agar to set, and keep the tubes at 

 38-5 C. 



Compare them from day to day for gas formation. 



(5) Inoculate three milk tubes with the same Varieties, 

 and keep them at 38 '5 C. 



Examine them from day to day for coagulation. 

 Curdling may be rapid or delayed or even absent. 



(6) Typhoid Spleen (vide also p. 135). 



Stain sections of typhoid spleen with Loffler's methylene- 

 blue or in Czinzinski's fluid, in the usual manner. 



Examine with a low and high power, and -% in. 

 oil immersion. 



(7) To stain the capsule of the Pneumococcus prepare the 

 following solution : 



Concentrated alcoholic solution of 



gentian-violet . . . 5 cc. 



Distilled water . . . . 10 cc. 



Glacial acetic acid . . . 1 cc. 



(a) In this solution stain films, prepared from pneumonic 

 sputum, for twenty-four hours. 



(b) Then wash in acetic acid (1 per cent) for one or two 



minutes. 



(c) Wash in water. 



(d) Dry between blotting-paper. 



(e) Mount in xylol balsam. 



Examine with - in. oil immersion. 



