370 



PLANT RESPONSE 



we may study the immediate and after-effects of rise of 

 temperature, and of the various chemical reagents. 



Fig. 157. Photograph of Shoshungraph 



V, plant-vessel ; R, reservoir ; c, compensator, whose balancing height is 

 adjusted by rack and pinion, s ; K, key for manipulation of four-way 

 stop-cock ; P, recording pen, |with counterpoise M, manipulated by 

 wheel, w. The drum is rotated by the clock at uniform speed. 



