Comparative Studies on Respiration

1. In relatively low concentrations of NaCl, KCl, and CaCl(2) the rate of respiration of Bacillus subtilis remains fairly constant for a period of several hours, while in the higher concentrations, there is a gradual decrease in the rate. 2. NaCl and KCl increase the rate of respiration of Bacillus subtilis somewhat at concentrations of 0.15 M and 0.2 M respectively; in sufficiently high concentrations they decrease the rate. CaCl(2) increases the rate of respiration of Bacillus subtilis at a concentration of 0.05 M and decreases the rate at somewhat higher concentrations. 3. The effects of salts upon respiration show a well marked antagonism between NaCl and CaCl(2), and between KCl and CaCl(2). The antagonism between NaCl and KCl is slight and the antagonism curve shows two maxima.