INJURY AND RECOVERY 



117 



noticed that in this and in some other experiments the 

 resistance rises rather more rapidly in CaCl 2 than the 

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



x Na Cl 

 o Ca C1 2 



D Sea Water 



400 



MINUTES 8OO 



FIG. 46. Curves showing the net electrical resistance of Laminaria aaardhii in NaCl 0.52 M , 

 m CaCl-2 0.278 M and in sea water. Unbroken line, calculated values; broken line, observed 

 values. Average of ten or more experiments; probable error of the mean less than 10% 



of the mean. 



fact that the " standard curve " for CaCl 2 , which was 

 based upon previous experiments made under different 

 conditions, seems to be a little too low for the 

 present material. 



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



A series of experiments was made to determine the 

 effect of CaClo followed directly by NaCl. The results 

 are shown in Fig. 47. The rise in CaCl 2 during the first 

 91.8 minutes is calculated in the usual manner. In order 

 to calculate the subsequent drop in NaCl we must substi- 

 tute for 77.1 in formula (9) 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 A, which is A l =2700e -(o.ooism.s 



