MECHANISM OF PROCESS OF DEATH 45 



same) an experiment was made in 10O 

 which the concentration of cal- 

 cium ions was kept undiminished. 

 For this purpose there was added 

 to a s a t u r a t e d solution of 

 Ca(OH) 2 (in distilled water) suffi- 

 cient CaCl 2 1.42 M to make the 

 conductivity equal to that of sea 

 water. Tissue was placed in this 

 and also in CaCl 2 0.278 M. In 

 spite of the fact that the concen- 

 tration of calcium ions was practi- 

 cally the same in the two solutions 

 the behavior of the tissue was 

 markedly different. In pure 

 CaCl 2 the net resistance rose to 

 171% of the original net resis- 

 tance while in CaCl 2 + Ca(OH)o 

 it rose to only 113%. At the end 

 of forty-five minutes the resis- 

 tance in CaCl 2 was 146%, while in 

 CaCl 2 +Ca(OH) 2 itwasonly23%. 



These experiments make it 

 evident that small amounts of 

 NaOH are able to produce a con- 

 siderable increase in permea- 

 bility. 11 



Let us now consider those sub- 

 stances which increase the resis- 

 of the tissue. In general we 



FEK CENT 



HOTTR 



Fiq. 17. Curves of net electrical 

 resistance of Laminaria agardhii 

 in a solution containing NaCl 97.2 

 mols of NaCl to 2.8 mols of CaCh 

 (uppermost curve) ; a solution con- 

 taining 97.2 mols NaCl to 2.8 mols 

 Ca(OH)2 (middle curve) and in 

 NaCl 0.52 M (lowest curve). All 

 the solutions had the conductivity 

 of sea water. All readings were 

 taken at 18 C. or corrected to this 

 temperature. Each curve repre- 

 sents a single typical experiment. 



find thatbivalentkations are very effective in this respect 12 



11 Cf. Osterhout (1914, F). 



12 Cf. Osterhout (1915, D). 



