VII 

 CULTIVATION EXPERIMENTS 



1. TECHNIC 



THE technic described by Plotz, Olitsky, and Baehr (1915) in 

 their monograph on the etiology of typhus was minutely fol- 

 lowed. We had ascitic fluid from only one source for these 

 experiments; but this ascitic fluid was sterile, free from bile 

 and had a specific gravity of 1020. It did not inhibit the 

 growth of other bacteria. 

 The steps of the procedure were as follows: 



1. The agar in test tubes of the diameter specified by Plotz 

 was melted and cooled to 40 C. 



2. Thirty cubic centimeters of blood was drawn under 

 aseptic conditions and two and a half cubic centimeters was 

 added to each of three tubes, each containing twenty cubic 

 centimeters of 2.5 per cent glucose agar. 



3. Four cubic centimeters of ascitic fluid was added to each 

 of the tubes containing glucose agar and blood. 



4. As controls to the manipulative part of the procedure 

 four cubic centimeters of ascitic fluid was added to each of 

 three tubes of the same agar to which no blood had been added. 



5. The contents of the tubes, cultures, and controls were 

 mixed by pouring back and forth into sterile test tubes. 



6. The cultures and control tubes of agar were hardened in 

 a vessel of ice-water. 



7. Four cubic centimeters of plain agar were added to each 

 tube of hardened medium. 



2. CASES 



In addition to the anaerobic cultures as prepared, we made 

 from each case aerobic cultures by adding the blood to glucose 

 broth in flasks and by plating in plain agar and in glucose agar. 



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