W. J. V. OSTERHOUT 613 



The value of L may be obtained by means of the formula 



,= 100- 2700 f _ \(e -e j + 90 e +10 



(5) 



in which K^ = 0.0036 and K^ = 0.1080 (these are the normal values 

 in sea water). 



After 20.8 minutes in the solution of NaCl the value of T^ (in 

 formulas (2), (3), and (4)) is 20.8 and the following results are 

 obtained: A = 1856.80, 5 = 484.06, M = 64.03, O = 88.41. When 

 the tissue has been replaced in sea water and left for 10.4 minutes' 

 the value of Tr (in formulas (1) and (5)) is 10.4 and the value of L 

 is found to be 1.33. 



Substituting these values in formula (1) we find that when the 

 tissue has been replaced in sea water the resistance at the end of 

 10,4 minutes is 83.49. Proceeding in this manner we calculate the 

 resistance at various intervals after replacement in sea water and 

 obtain the first (calculated) recovery curve shown in Fig. 1. It is 

 evident that it is in fairly good agreement with the observed values. 



After 200 minutes in sea water (during which the resistance rose 

 to 87.10 per cent and remained practically constant) the tissue was 

 replaced in the solution of NaCl. In the course of 21.2 minutes* 

 the resistance fell from 87.10 to 64.18. It was then replaced in sea 

 water. The recovery curve may be calculated as before, the only 

 differences being as follows : 



1. On replacing the tissue in sea water the destruction of (by 

 the reactions N^D—>P) ceases (or becomes negligible); hence the 

 value of O at the beginning of the second exposure (if equilibrium 

 has been reached) is that of the observed resistance less 10, or 87.10 — 

 10 = 77.10. We find by means of formula (4) that when at the 

 start equals 90 it loses 11.95 during an exposure of 21.2 minutes to 

 the solution of NaCl, but as it only equals 77.10 at the start the loss 

 will be 11.95 (77.10-^90) = 10.23. Subtracting this from 77.10 gives 

 66.87, the value of at the end of the second exposure, and adding 

 10 (since the base Hne is 10) makes 76.87, the level to which the resist- 

 ance should rise after the second exposure. 



' This is corrected from 10 minutes' as explained in a former paper. 

 *The actual time was 20 minutes: the manner in which the corrected figure is 

 obtained is explained in a subsequent paragraph. * 



