INJUEY AND EECOVERY 113 



period in sea water the speed of recovery will fall off 

 somewhat with each successive exposure. 



4. The value of M is the observed resistance (at the 

 end of the second exposure) less 10 or 64.18 — 10 = 54.18. 



5. The value of A is obtained by multiplying by 30 

 the resistance observed at equilibrium (less 10). This is 

 based upon the following considerations: 



Just before the beginning of the second exposure A 

 and M are assumed to be in equilibrium in sea water, in 

 which case as much of A must decompose in any minute 

 as of M ( otherwise M would not remain constant) . But the 

 amount of A which decomposes in 1 minute is AK^ and 

 of M is MKj^; and since -Kj^ is 30 times as great as K^ it 

 follows that ^ ^ 30 M. At the begiiming of the second 

 exposure M= 87.10 — 10= 77.10 and ^= (77.10) 

 30 = 2313. 



In order to ascertain how the resistance would change 

 during the second exposure if it conformed to the 

 standard curve previously employed, we may employ 

 the formula 



^ • <,o,ni "^ 11 -KaTe -KmTe\ 



Eesistance = 2313| j^— ^^s^ 11^ _, I 



'\Km-KaJ \< 





-KmTe (Q) 



+77.1 e +10 ^ ' 



in which 5:^ = 0.018, ^3,= 0.540 and T^=time the tis- 

 sue has remained in the solution of NaCl. Comparing the 

 values thus obtained with the observed resistance after 

 an exposure of 20 minutes we find that if the time is 

 multiplied by 1.06 (making it 21,2 minutes) the observed 

 resistance (64.18) agrees with the standard curve. This 

 figure is therefore adopted. The value of T^ in formulas 



