= 3 i°C. 

 = 33-5 mm. 

 = 752-3 mm. 



= 0-014 c.c. 

 = 0-00144 g rm - 



236 CHAP. XXV. PHOTOSYNTHETIC STORAGE OF SOLAR ENERGY 



Energy stored in carbohydrate products. 



Constant of the Bubbler = 0-0014 c c 



Temperature during the 



experiment 

 Tension of aqueous vapour 

 Barometric pressure 



The volume of oxygen evolved 



under radiation per minute 

 Weight of 1 c.c. of oxygen N.T.P. 

 The carbohydrate-factor for oxygen == o • 8906 

 Weight of carbohydrate formed per minute 



_ o-oi4 x 273 X (752-3-33-5) X 0-00144 X 0-8906 



(273 + 31) X760 

 = 0-00001512 grm. 

 The heat of combustion per gramme of carbohydrate 



= 3-9 X io 3 cal. 

 Hence energy stored per minute =0-0000152 X 3-9 X io 3 



= 0-0595 cal. 



t-.cc • Energy stored 0-0595 _ , 



Efficiency = = =H : — r = ^-^ = 5-76 per cent. 



Energy absorbed 1-032 



The results of three other experiments are given in the 

 following table : 



Table XXXIII. — Photosynthetic Efficiency of Leaves of Hydrilla 



