RESISTANCE OF STREPTOCOCCI 79 



justing the temperature to 0.5 reaction, with phenolphthalein as 

 the indicator. From 10 to 15 c. c. of the blood agar were poured 

 into each Petri dish. 



FINDINGS 



The results of our experiments have been placed in Tables 

 1 and 2. Table 1 shows the effects of various germicides in re- 

 ducing the number of streptococci or entirely destroying them 

 after periods of exposure varying from one-fourth minute to one 

 hour. Table 2 indicates the shortest time in which all strep- 

 tococci of a given culture were killed by various germicides as 

 well as a list of those germicides which failed to kill all the strep- 

 tococci at the end of one hour. 



The letters "h" and "v" in the column under "Types of Strep- 

 tococci" refer to "hemolyticus" and "viridans" respectively. The 

 plus and minus signs in the column under "G" refer to the pre- 

 sence or absence of growth in the broth tubes. The figures in 

 the column under "No." refer to the number of bacteria living in a 

 given volume (as explained in the discussion of the technic), after 

 the disinfectant had been j^ermitted to act for a given length of 

 time, as represented in Table 1. The number of bacteria was de- 

 termined by the number of colonies that developed on the blood- 

 agar plates. In order that the figures may be made comparable, 

 thev have been reduced to a basis of a control of 1,000 colonies. 



