56 GENERAL BACTERIOLOGY LESSON 



(8) Stain pneumonic sputum kept in carbolic acid ly 

 Weigerfs method, counterstaining with cosine. 



(a) Prepare thin films, as previously described, and after 

 having passed them three times through the flame, wash 

 them in the alcohol-ether mixture (vide p. 48). 



(b) Dry the films, and again pass them through the flame. 



(c) Stain them with aniline gentian-violet for fifteen to 

 thirty minutes. 



(d) Wash them in *6 per cent saline solution. 



(e) Place them in Weigert's iodine solution (iodine 1, 

 pot. iod. 2, water 100) for two to three minutes. 



(/) Dry thoroughly with filter-paper, and pour a weak 

 alcoholic solution of eosine over the cover-glass, and allow 

 this to act for thirty seconds or less. 



(g) Quickly wash in *6 per cent saline solution. 



(h) Dry again with filter-paper, and decolourise with the 

 anilme-xylol solution till the specimen is pink. 



(i) Wash with xylol arid mount in xylol balsam. 

 Examine with -^ in- oil immersion. 



If the sputum has not been kept in carbolic acid, 

 prepare thin films of the fresh viscid sputum, and after 

 passing the dry films three times through the flame, at once 

 proceed to stain \vith the aniline gentian-violet, and continue 

 as above. 



Diphtheria 



(1) Inoculate a serum agar-agar tube (streak), and 

 a gelatine tube (streak) from an agar-agar culture. Keep 



