DETERMINATION OF COEFFICIENT 



39 



the ratio of the increase in photosynthetic activity to the 

 increment of light which induces it. If A L be the activity 



for intensity of light L, and A/ that for intensity / ; then 



the coefficient 



K = 



A/ 



(2) 



L - / 

 The unit of light, it should be remembered, is ioo lux. 



The following are the determinations made for the spring- 

 and winter-specimens : 



Spring-specimens : 



I. Activity for 300 lux = 77-1 c.mm. per hour 

 1000 ,, -=265-6 

 Increase in activity = 188-5 

 Increase in intensity of light = 700 lux 



v l88> 5 r 



K = =26-0 



10-3 



II. (a) Activity for 300 lux = 62-4 



750 .. =173-4 



T7 . 173-4 — 62-4 



K = /J ^ -= 24-7 



7'5-3 



(b) Activity for 500 lux = no-2 



1000 „ =234-8 



234-8 — II0-2 



K = 



24-9 



10-5 



III. Activity for 500 lux = 125-6 



1000 ,, =240-0 



-^ 240-0 — 125-6 



10-5 



22-9 



Winter-specimens : 



IV. Activity for 450 lux = 29-5 

 1125 „ =102-0 



K 



102-0 



29-5 _ 



11-25 - 4*5 



= io-8 



