622 



STUDIES ON RESPIRATION. XI 



Kd.te of COs production 

 122^ 



100 



60 mm. 



Fig. 1. Respiration of Poiicilliuni chrysogenum expressed as per cent of the 

 normal (at pH 7). The material was put in the test solution at the point marked 

 on the abscissa and the line at the left of this point represents the normal 

 respiration. Curve A represents the respiration in a solution having a pH of 7 

 (normal); Curve B in pH 1.10; Curve C in pH 1.95; Curve D in pH 2.65; and 

 Curve E in pH 8.80. The normal rate represents a change in the indicator tube 

 from pH 7.94 to 7.52 in from 2 to 3 minutes depending upon the amount of mate- 

 rial used. The probable error was less than 5 per cent of the mean, except at 

 the last point with pH 1.95 where it was 6.5 per cent of the mean. 



