10 



STUDIES ON RESPIRATION. VHI 



Fig. 2 shows the manner in which the rate of CO2 production changes 

 under the influence of CaCl2 in the concentrations of 0.02, 0.05, 0.1, 

 0.25, 0.35, and 1.0 m. In 0.01, 0.02, and 0.1 m the rate is normal; in 

 0.05 M there is an increase in rate; in higher concentrations there is a 

 decrease in rate. These curves are selected from a number of similar 

 typical curves, and each represents one experiment. 



Rate of CC^ production 



100- 



50 



-O0.SM 



-aczn 



-• 1.0M 



^ 



S) min. 



Fig. 3. Curves showing the rate of respiration of Bacillus suhtilis (expressed as 

 per cent of the normal) in 0.2 m, 0.3 M, and 1.0 M KCl. The zero point on the 

 abscissa denotes the beginning of exposure to the salt solution; previous to this the 

 bacteria were in 0.75 per cent solution of dextrose in distilled water. The normal 

 rate (which is taken as 100 per cent) represents a change in pH value from 7.78 

 to 7.60 in a number of seconds depending upon the amount of bacterial susi>en- 

 sion, usually 30 seconds. Each curve represents a single typical experiment. 



