DIRECT AND INDIRECT METHODS OF DETERMINATION 213 



in the Eudiometer : this multiplied by the carbohydrate- 

 factor gives the calculated value of the carbohydrate 

 produced under light. The results obtained by these two 

 entirely different methods can then be compared. 



R 



n\o ' elo mo ' *lo ' it I voj w ' gfe e» ' ^° 1 



Fig. 53. Chemical Balance for determination of increase of 

 weight of Hydrilla after exposure to Light 

 Vessel v always kept on the Balance. 



Experimental details. — The following gives the experi- 

 mental details of the procedure adopted. Two vessels filled 

 with the same water containing the normal proportion of C0 2 



