146 



THEORY OF INJURY AND RECOVERY 



with considerable accuracy by assuming that the electrical resistance 

 is proportional to the amount of a substance in the cell which increases 

 or decreases according to the relative proportion of salts in the external 

 solution. 



We assume that this substance (M) is formed and decomposed by 

 a series of reactions^ of the type* 



100^1 



150 min. 



Fig. 1. Curves showing the fall of electrical resistance of Laminaria agardhii 

 in 0.vS2 Ai NaCl (descending curve) and recovery in sea water (ascending curves). 

 The figure attached to each recovery curve denotes the time of exposure (in 

 minutes) of the solution of NaCl. 



In the recovery curves the experimental results are shown by dotted lines, 

 the calculated results by the unbroken Unes (the curves are extended beyond the 

 last observed point here shown because of later observations which are not shown 

 in the figure) . 



The observed points represent the average of eight or more experiments; 

 probable error of the mean less than 10 per cent of the mean. 



^ These are regarded as irreversible or practically so. 



* It is assumed that is present in relatively large amount so that it may 

 be regarded as practically constant despite the fact that it very slowly decomposes 

 to furnish S, A, M, and B. 



