620 



THEORY OF INJURY AND RECOVERY. HI 



V. CaCh, NaCl, CaCh, NaCl, Sea Water, etc. 



A series of experiments was performed in which tissue was placed 

 in CaCl2 for 30 minutes, then in NaCl for 10 minutes, then in CaCl2 

 for 60 minutes. The tissue was allowed to recover in sea water, 

 after which it was placed in CaCl2 for 360 minutes, and then in NaCl. 



X NaCl 

 o Ca CI 



D SeaWatep 



O 400 MINUTES 800 



Fig. 5. Curves showing the electrical resistance of Laminaria agardhii in NaCl 

 0.52m, in CaCU 0.278m 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 per cent of the mean. 



In this case the observed time was not corrected (i.e., was not 

 multiplied by a factor) as in the previous calculations. In conse- 

 quence the calculated and observed values do not correspond at the 

 beginning of each exposure, the only exception being after recovery 

 in sea water, in which case it was assumed^** that equilibrium had been 



^^ In this case the tissue did not remain long enough in sea water to establish 

 equihbrium but it was so nearly established that only a very small error is involved 

 in regarding it as complete. In cases where it is not completely established the 

 final equihbrium may be approximated with sufficient accuracy by extrapolation. 



