INJURY AND RECOVERY 119 



ing the 60.6 minutes in NaCl R 1 diminishes to R 2 accord- 

 ing to the formula 



KR in NaCl = 0.04998. 



We must also bear in mind that diminishes during 

 the exposure. Since this process is 6 times as rapid in 

 NaCl as in CaCl 2 we may consider 91.8 minutes in CaCl 2 

 to be equivalent to 91.8 -f- 6 = 15.3 minutes in NaCl and 

 the total exposure to be equivalent to 60.6 + 15.3 = 75.9 

 minutes in NaCl. 37 The value of may then be found by 

 means of formula (5). 



V. CaCl 2 , NaCl, CaCl 2 , NaCl, Sea Water, etc. 



A series of experiments was performed in which 

 tissue was placed in CaCl 2 for 30 minutes, then in NaCl 

 for 10 minutes, then in CaCL for 60 minutes. The tissue 

 was allowed to recover in sea water, after which it was 

 placed in CaCl 2 for 360 minutes, and then in NaCl 

 (Fig. 48). 



In this case the observed time was not corrected (i.e., 

 was not multiplied by a factor) as in the previous calcu- 

 lations. In consequence the calculated and observed 

 values do not correspond at the beginning of each expos- 

 ure, the only exception being after recovery in sea water, 

 in which case it was assumed 38 that equilibrium had been 



" This involves the assumption that is not restored to any extent dur- 

 ing recovery in sea water. This assumption may not be correct, especially 

 at the start, but even in that case the present calculation would not be 

 appreciably altered. 



88 In this case the tissue did not remain long enough in sea water to 

 establish equilibrium, but it was so nearly established that only a very 

 small error is involved in regarding it as complete. In cases where it is 

 not completely established the final equilibrium may be approximated 

 by extrapolation. 



