CALCULATION OF DATA 



193 



ning of the measurement. Application of this correction changes the ex- 

 perimental values slightly. The numbers in the last column under the 

 experimental manometer were derived by multiplying by the constant, 

 an operation which converts (corrected) millimeters of manometer fluid 

 to microliters of oxygen at standard conditions. 



Fig. 14-1, Record of a manometric measurement of photosynthesis; 

 student data. 



Further computations can be made. We know the amount of oxygen 

 produced in thirty minutes by this lot of Chlorella cells. The average 

 rate of photosynthesis (in fJi\ 02/hr) is given by multiplication. We know 

 the volume of the cells and the amount of chlorophyll they contain, so 

 we can calculate the rate in any terms we choose. 



In some experiments it is possible to combine all the corrections and 

 computations in a single equation. Using the number of millimeters of 

 manometer fluid (corrected by thermobarometer reading) from Fig. 14-1, 

 we can compute the rate of photosynthesis in ^tl Oo/^tg chlorophyll X hr 

 by the following equation: 



