MECHANISM OF PROCESS OP DEATH 49 



tissue falls from 15.2% to 13.53%, thereby losing 11% of 

 the resistance it had in sea water. This corresponds 

 quite closely to the loss of resistance of the sea water 

 itself upon the addition of this amount of CaCl 2 . 



Experiments were also performed by placing tissue in 

 solutions (having the same conductivity as sea water) 

 which contained only one salt. It was found (Fig. 20) 

 that the bivalent Ca, Ba, Sr, and Mn raised the resistance 

 (increasing it to 160% or more) while the trivalent La 

 and Ce gave a much greater rise (increasing it to 220% 

 or more). On the other hand, Mg gave very little rise 

 (increasing the resistance as a rule to not more than 

 115%). In this respect its behavior is not unexpected, 

 since it is usually less effective than other bivalent kations 

 (as for example in antagonizing the effects of Na). 18 



It was found that Ulva (sea lettuce) and Zoster a (eel 

 grass) resemble Laminaria in showing a rise with MgCL 

 and a much greater rise with CaCl 2 . 19 Rhodymenia 

 palmata (dulse) agrees with Laminaria in showing a 

 rise in resistance in 20 CaCl 2 , BaCl 2 , SrCl 2 , MnCL, and 

 NiCl 2 , and a greater rise in alum, Ce(N0 3 ) 3 , and 

 La(N0 3 ) 3 . The rise with MgCl 2 is less than with 

 CaCL, but the latter is less than that found with Lami- 

 naria (Fig. 21). 



Experiments on frog skin 21 showed a rapid rise in 

 CaCl 2 (resistance increased to 140%, or less) followed 

 by a fall. In La(N0 3 ) 3 the rise is greater (resistance 

 increased to 190% or less) and in MgCl 2 it is less 

 (resistance increased to 110%, or less). It is evident 



"See Chapter IV. 

 ^Osterhout (1919, A). 

 ^Osterhout (1919, A). 

 21 C/. Osterhout (1919, C.). 



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