In the present work we have extended these experiments by the use of the plate count in an effort to throw more light on the mechbanism of the salt action. Since our previous experiments have shown that the salt effect is magnified on the acid side of the region of optimum growth (Sherman and Holm, 1922), we have used in the present work media adjusted to a reaction of pH . All of the counts here reported represent the average of triplicate plates on extract-pepton agar incubated for three days at 33°C. Further details of the experiments are given in the appendix.
