Rate of CO2 production 

 A 7.3% 



220% 



75 150 mms. 



Fig. 1. Curves showing the rate of respiration of wheat seedlings (expressed as 

 per cent of the normal), in 1 per cent, 3.65 per cent, and 7.3 per cent ether (by 

 volume). The normal rate (which is taken as 100 per cent), represents a change 

 in pH value from 7.36 to 7.09 in a number of seconds varying with the age of the 

 material, usually between 30 and 60 seconds. The curve with 1 per cent ether 

 represents the mean of five typical experiments (probable error of the mean, less 

 than 10 per cent of the mean). The curve with 3.65 per cent ether represents 

 the mean of ten typical experiments (probable error of the mean, less than 5 

 per cent of the mean). The curve with 7.3 per cent ether represents the mean of 

 six experiments (probable error of the mean, less than 5 per cent of the mean, 

 except for two points, where the error is 10 per cent of the mean). 



159 



