Toxic AND ANTITOXIC EFFECTS OF IONS 717 



To supplement these results the following table dealing 

 with the effects of a more concentrated ZnSO 4 solution and 

 a more dilute Nad solution than that of the previous table 

 may be given: 



TABLE VII 



The remaining experiments showed a similar agreement 

 in the results obtained. It is worthy of note that these 

 embryos remained alive over a week, possessed an entirely 

 normal circulation, and moved in the egg. 



The experiments with freshly prepared FeSO 4 yielded as 

 striking results as the above. Only in these experiments the 

 transformation of the bivalent into the trivalent Fe ion 

 introduces a disturbing element. We shall see later that the 

 ferric ion is apparently extremely poisonous. The addition 

 of ^ c.c. or 1 c.c. of a freshly prepared FeSO 4 solution 

 to 100 c.c. of f m NaCl solution annihilates the poisonous 

 effect of the pure sodium-chloride solution just as com- 

 pletely as the addition of the Zn ions in the previous ex- 

 periment. 



Then I tried whether cobalt ions are capable of anni- 

 hilating the antitoxic effects of a pure sodium-chloride solu- 

 tion. The results were very clear indeed. 



Since the amount of the bivalent kation capable of exhib- 

 iting its antitoxic properties was so extraordinarily small, I 

 risked the attempt to annihilate the poisonous effects of a 

 pure sodium -chloride solution through the addition of Pb, 



