616 THEORY OF INJURY AND RECOVERY, ni 



• Loss = 2700 - ( 2700. " ^^-^'^'^l'-' ) = 97.26 (8) 



and this could be completely replaced by O if O were intact. But 

 since O has diminished^ from 90 to 50.86 it can supply only 

 97.26(50.86 -^ 90) = 54.95. This must be added to A giving A^ = 

 A 4 + 54.95. The value o( A5 must be substituted for 2313 in formula 

 (7). This enables us to calculate the fall of resistance after the last 

 recovery (of 10.2 minutes). Fig. 1 shows the values so obtained and 

 also the observed values. 



II. Alternate Exposure to CaCh cmd Sea Water. 



When the tissue of Laminaria is transferred from sea water to a 

 solution of CaCl2 (of the same conductivity as sea water) the resist- 

 ance rises and then falls as shown in Fig. 2. When it is replaced in 

 sea water the resistance falls (much more rapidly than if left in the 

 solution of CaCl2) and eventually becomes stationary. This fall 

 of resistance may be spoken of as recovery, since it may be regarded 

 as analagous to the rise of resistance which occurs when tissue is 

 transferred from NaCl to sea water. 



Recovery after exposure to CaCl2 may be calculated in precisely 

 the same manner as recovery after exposure to NaCl. The only 

 difference is that in formulas (2), (3), (4), (6), and (7) we must 

 employ for the velocity constants {K^, Kg, Kj^, Ks, K^ and Km) 

 the values given for CaCl2 in Table II of the preceding paper. ^ In 

 formulas (1) and (5) the values of the velocity constants are always 

 the same {K^ = 0.0036 and Km = 0.1080) since these are the values 

 which are normal for sea water. 



Results of such calculations are shown in Fig. 2 together with the 

 observed values. 



''This is calculated as follows: At the beginning of the fourth exposure = 

 68.10 — 10 = 58.10. If its value were 90 it would lose 11.23 during an exposure 

 of 20.4 minutes to NaCl. Since = 58.10 the loss will be 11.23 (58.10 + 90) 

 = 7.24: subtracting this from 58.10 we have 50.86. 



8 Osterhout, W. J. V., J. Gen. Physiol, 1920-21, iii, 415. 



