EFFECT OF INCREASING STRENGTHS OF MALIC ACID 120. 



It is clear that malic acid serves as a perfect substitute for 

 C0 2 in photosynthesis in acid specimens. I have, in fact, 

 tried the effects of C0 2 and of malic acid alternately on the 



Fig. 36. Photosynthetic Curves under Increasing Concentration 

 of C0 2 (upper curve) and of Malic Acid Solution (lower 

 curve) 



The upper abscissa represents CO a -concentration in mg. per 

 100 c.c. ; the dotted lower shows n parts of malic acid in 

 10,000 parts of water. 



same plant, and have found that the previous action of malic 

 acid produced no prejudicial effect on the normal photo- 

 synthetic action with carbon dioxide. Care should, how- 

 ever, be taken to avoid an excessively strong dose of malic 

 acid, which has'a toxic effect. 



