VARIATIONS IN TYPHOID BACILLI 



315 



III. 3 cc. of each bacterial suspension plus 1 cc. of N/4 HCl 

 plus 1 cc. of N/4 NaOH. 



To 0.5 cc. of each of these mixtures graded serum dilutions 

 from 1 : 100 to 1 : 25,800 were added; also to a salt solution control. 



Results were as follows : 



+S = slight agglutination. 



In another experiment suspension I, II (without the addition 

 of 1 cc. of salt solution) and III (without the addition of 1 cc. 

 of N/4 NaOH solution) were made up. They were heated at 

 80°C. in a water bath for fifteen minutes, and then cooled in 

 cold water. To no. II, 1 cc. of salt solution and to no. Ill, 

 1 cc. of N/4 NaOH solution were added respectively. After 

 being shaken well, 0.5 cc. of each suspension was added to each 

 of the serum dilutions described above. 



The results were as f oUows : 



