78 



M. E. COLLETT 



the former to ten of the latter, there is a marked change in anti- 

 toxic action. With most of the alkahne earth chlorides antago- 

 nistic power may be increased 50 per cent or more by the addition 

 of NaCl; the amount of increase varies with the concentration of 

 the salts. For example, with Paramecium the power of BaCl2 



TABLE 2 



SALTS ALONE 



Concentration of salts M 



Monavalent cations 



Bivalent cations 



NaCl 



KCl.... 



NH4CI 



BaCl. 



CaCl, 



MgClo 



SrCl2 



BaCl2 plus NaCl 



CaCl. plus NaCI 



MgCls plus NaCI 



SrClo plus NaCl 



CdCl2 



C0CI2 



MnCl2 



NiCl, 



ZnCl2 



CdClo plus NaCl 



C0CI2 plus NaCl 



MnCl2 plus NaCl .... 



NiCl2 plus NaCl 



ZnCl2 plus NaCl 



0.0001 

 0.0001 



25 



7 



LENGTH OF LIFE IN MINUTES 



Paramecium 



0.01 

 0.001 



15h 



< 1 



< 1 



0.05 

 0.005 



2h 



<1 



6 

 3 



1 

 15 



25+ 



0.1 

 0.01 



40' 



25 

 90+ 

 10 

 100+ 



20 

 100 



40 

 100+ 



<1 



6 



25 



Euplotes 



0.1 

 0.0001 



25 

 12 



5 

 <5 



0.01 

 9.001 



15h 



25' 



15 

 11 



<5 



<5 



0.05 

 0.005 



20 

 35 



90+ 



11 



9 



90 



0.1 

 01 



<90 

 90+ 

 90 

 90 



90+ 

 90+ 

 10 

 5 



20 



30 



120+ 



5 



7 

 90 



0.005 M to antagonize the toxic action of acetic is increased 100 

 per cent by the addition of NaCl ; but the addition of NaCl does 

 not in any way improve the antitoxic power of BaClo at other 

 concentrations (0.001 or 0.01 M). Similarly, the antitoxic 

 power of CaClg and SrCl2 at 0.001 or 0.005M is decidedly increased 



