246 



CHAP. XXVI. THE PHYSIOLOGICAL SCALE 



9°-8 

 activity =147 -9 



Specimen II. Physiological zero . 



(a) Temp. i7°-oC. ; T=iy- — 9-8=7-2 



K=20-5 



(b) Temp. 24°-2C. ; 1=24-2 — 9-8=14-4: activity =288 -4 



K=20-0 



In Table XXXIV. the first column gives the physiological 

 zero, also the average of coefficient K obtained by the 

 Differential Method. The second column gives the tem- 

 perature in centigrade ; the third column the temperature T 

 on the physiological scale ; the fourth column the activity 

 A ; the last column gives the coefficient K. 



Law of Photosynthesis for Variation of 

 Temperature 



It will be seen that the photosynthetic coefficient K, 

 whether determined by the differential or by the direct 

 method, is practically the same ; while the former method 

 gives only the average value, the latter gives it for every 

 point in the median range. The coefficient for the median 

 range is found to be a constant. 



The general law of photosynthesis under variation of tem- 

 perature is — 



— is a constant. 



Table XXXV. — Determination of Coefficient for Co 2 -Concentra- 

 tion from Measurements on the Physiological Scale 



