C0 2 -CONCENTRATION, LIGHT, AND TEMPERATURE 263 



Hence activity for S at temperature 29 C. is — 



Theoretically (1) X (4) X activity at 21 for 0-4 S 

 = 2-5 X 2-67 X 88-5 = 590-7 c.mm. 

 Observed value = 585-0 „ 



The agreement between the theoretical and the observed 

 results is again most remarkable. 



V. Three Variables : C0 2 -Concentration, Light, 

 and Temperature 



In this set of experiments all these three different factors 

 underwent variation ; the different combinations were : 



clt; CU; CO; CLT. 



(a) c = 3 ; / = 750 lux ;t = 2i° activity =50-4 c.mm. O 

 (&)C = 7-5;/= 750 „ t = 2i° „ = 83-4 „ 

 (c)C=7«5;L=i5oo „ * = 21 „ =163-8 „ 

 (i)C = 7-5;L=i5oo „ T=26-6° „ =245-4 „ 



From (a) and (b) the partial factor for C0 2 -concentration is : 



Activity at C0 2 -concentration 7 • 5 _ 83 • 4 



= 1-65 . (1) 



Activity at C0 2 -concentration 3-0 50-4 

 From (b) and (c) the partial factor for light is — 



Activity at 1500 lux _ 163 ■ 8 _ fi , . 



Activity at 750 lux " 83-4 



As regards the factor for temperature-variation, it has 

 been previously shown that the physiological zero varies 

 between 9 • 2 and 9 • 8. In the present case it is 9 • 6. 



A T_ T-9-6 

 A t t-g-6 



Hence the partial factor for temperature variation from 21 



to 26°-6— 



26-6 — 0-6 , . 

 ^— = 1.40 . . (3) 



21-0 — 9-6 ^ w/ 



From the above, the enhancement of activity from c, I, t, 

 to C, L, T, is — 



