INJURY AND EECOVERY 



117 



noticed that in this and in some other experiments the 

 resistance rises rather more rapidly in CaCla than the 

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



4oo 



MINUTES 800 



FiQ. 46. — Curves showing the net electrical resistance of LaminaTia agardhii in NaCl 0.52 M, 

 in CaCls 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 CaCla, which was 

 based upon previous experiments made under different 

 conditions, seems to be a little too low for the 

 present material. 



IV. CaClo_, NaCl, Sea Water, etc. 



A series of experiments was made to determine the 

 effect of CaCla followed directly by NaCl. The results 

 are shown in Fig. 47. The rise in OaClg 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^ =2700e -(o.ooi8)9i.8 



