Relative quantity of hydrogen-ion absorbed 
[ 128 ] 
PERMEABILITY 
By WALTER STILES 
CHAPTER XII {continued) 
QUANTITATIVE RELATIONS IN THE PENETRATION OF 
DISSOLVED SUBSTANCES INTO PLANT CELLS (< continued) 
Influence of temperature on the rate of absorption. The effect of 
temperature on the rate of absorption was examined by Stiles and 
Jprgensen (1915 b) for the case of the absorption of hydrochloric acid. 
Fig. 15. Curves to illustrate the absorption of hydrogen-ion by potato tuber 
tissue immersed in 00011 N hydrochloric acid at various temperatures. 
(From the data of Stiles and Jorgensen.) 
or rather the hydrogen ions of that acid, by potato tuber. The tissue 
was used in the form of circular disks i-o cm. in diameter and 0-2 cm. 
in thickness, 20 disks being immersed in 100 c.c. of the acid solution. 
