490 Mr. W. Stiles and Dr. F. Kidd. The Comparative 



very high, namely 315, and it is found that the hydrogen ion is very rapidly 

 absorbed from hydrogen chloride, and indeed from all acids (2). 



The total amount of absorption is, however, as one would suppose, not 

 conditioned by ionic mobility, but by some other factor, for calcium chloride, 

 which after one hour has been absorbed to a greater extent than any other 

 chloride except that of potassium, after 18 hours has fallen well behind all 

 the others, which, however, maintain their relative positions. The initial 

 order of absorption of kations from the chlorides thus appears to be K, Ca, 

 Na, Li, while as regards total quantity absorbed it is K, Na, Li, Ca. The 

 relative positions of lithium and calcium are a little doubtful, as at the end 

 of the experiment there is actually a little more apparent absorption from 

 calcium than from lithium chloride. It must be remembered that the 

 numbers are only approximate, as they neglect exosmosis. Although this is 

 undoubtedly negligible in the case of non-toxic solutions, yet lithium is 

 generally regarded as somewhat toxic, and it is possible that there is more 

 exosmosis from the tissue in the case of lithium than with the other 

 chlorides (11). 



In regard to the general course of absorption the curves are approxi- 

 mately logarithmic after the first few hours. During the initial period, 

 however, the rate of withdrawal of salt from the solution is more 

 rapid than it would be if the same logarithmic relation between time and 

 intake held from the beginning. This suggests that there is an initial 

 process at work rapidly withdrawing salt from the solution, which is followed 

 by a slow general process which continues for several days before equili 

 brium is reached. If the results are expressed in terms of the percentage 

 of salt required to produce equilibrium, the parts of the curves where the 

 general process predominates all follow the same approximate course, showing 

 that absorption proceeds to equilibrium at the same rate. Thus, although 

 the initial rates of intake may be dependent on the mobility of the ions, in 

 regard to the general course of absorption, the differences in rate of intake 

 appear to be directly due to the position of equilibrium. 



The initial absorption from solutions of the same salts by potato is 

 similar, but the absorption is soon masked by the exosmosis that supervenes 

 in the case of this more sensitive tissue. The numbers obtained experi- 

 mentally are shown in Table III, and these results are exhibited graphically 

 in fig. 2. The initial order of absorption is K, Na, Ca, Li. 



