618 THEORY OF INJURY AND RECOVERY. HI 



///. NaCl, Sea Water, CaCh, Sea Water, etc. 



It seemed desirable to test the theory further by varying the experi- 

 ments in the manner shown in Fig. 3. The calculations are made as 

 already explained. It will be noticed that in this and in some other 

 experiments the resistance rises rather more rapidly in CaCl2 than 

 the calculations would lead us to expect. This is due to the fact that 

 the "standard curve" for CaCl2, which was based upon previous 

 experiments made under different conditions, seems to be a little too 

 low for the present material. 



IV. CaCk, NaCl, Sea Water, etc. 



A series of experiments was made to determine the effect of CaCl2 

 followed directly by NaCl. The results are shown in Fig. 4. The 

 rise in CaCl2 during the first 91.8 minutes is calculated in the usual 

 manner. In order to calculate the subsequent drop in NaCl we 

 must substitute in formula (7) the value of M; i.e., the observed 

 resistance (less 10) at the beginning of exposure to NaCl. In place of 

 2313 we must substitute the value of ^, which is Ai = 2700e~^°'°°^^^^^'^. 



During the exposure of 60.6 minutes to NaCl the value of A changes 

 iromA,toA, = A,e-''''''''\ 



This value must be substituted for A in Formula (1) in calculating 

 the recovery in sea water. 



In finding the value of S (by means of formula (3)) we must remem- 

 ber that during the 91.8 minutes in CaCl2 the value of R (which at the 

 start is Rq = 1041,77) diminishes from Rq to Ri according to the 

 formula 



-91.S Kr 

 Ri = Roe 



Kr in CaCl2 = 0.012532 (See Table II of the preceding paper^). 

 During the 60.6 minutes in NaCl Ri diminishes to R^ according to the 

 formula 



i^:^ 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 CaCl2 we may 



