372 APPLICATION OF METHODS OF BACTERIOLOGY 



the media that have been successfully used for its cultiva- 

 tion this substance is apparently an essential constituent. 



It was first isolated in culture by Bumm, who used for 

 this purpose coagulated human blood serum obtained from 

 the placenta. 



Wertheim improved the method of Bumm by using a 

 mixture of equal parts of sterile human blood serum and 

 ordinary sterilized nutrient agar-agar, the latter having 

 been liquefied and kept at 50 C. until after the mixture 

 was made, when it was allowed to cool and solidify. 



Other investigators have substituted for human blood 

 serum certain pathological fluids from the human body, 

 such as ascites-fluid, fluid from ovarian cysts, and serous 

 effusions from the pleura and from the joint-cavities. 



The method used by Pfeiffer for the cultivation of bac- 

 terium influenzse (see that method) is also said to have been 

 successfully employed. 



A simple medium that has given satisfactory results in 

 our hands is that devised by Vedder. It consists of ordi- 

 nary beef infusion agar (1.5 per cent, agar) to which 1 per 

 cent, of corn starch is added. The medium contains neither 

 sodium chloride nor peptone and has a reaction correspond- 

 ing to 0.2 to 0.5 per cent, acid to phenolphthalein. 



Wassermann 1 calls attention to the success he has had 

 in cultivating this organism upon a mixture of swine serum 

 and nitrose, the latter being a commercial product chemically 

 known as casein-sodium phosphate. 



The preparation of the medium and its composition are 

 as follows: 



In an Erlenmeyer flask mix 15 c.c. of swine serum, as 



1 Zeitschiift fur Hygiene und Infektionskrankheiten, Bd. xvii, p. 298. 



