71 



calcium to lead at the three concentrations of P"b(NC3)2 

 employed produced the same effect on spore germination. 

 With Zn(N03)2 1 molecule of calcium to 80 molecules of 

 zinc was found to reduce the toxicity of the latter to one 

 twentieth. It is difficult to believe the rate of adsorp- 

 tion of this relatively high concentration of zinc salt 

 can be so greatly reduced by the addition of such a small 

 amount of calciiim. 



In combinations of A1{NC3)2 with CaCNO^jg or 

 Mg (1103)2 the toxicity of the aluminum salt is not reduced 

 at all. It was to be expected, from the results obtained 

 by Loeb32 in his experiments upon the influence of NaCl 

 upon the toxicity of ^nSO^, that a higher molecular prop- 

 ortion of the bivalent metal would be needed to inhibit 

 the toxicity of the trivalent aluminum than was required 

 in the case of bivalent poisons. The work of Szucs (I.e. 

 page ) on the relative effeciency of certain metals 

 of different valencies in inhibiting the poisonous action 

 of quinine hydrochloride and the comparitive proportions 

 of KKC3 and Ca(NC3)2 required to noticeably influence the 

 toxicity of copper in the present work are in accord with 

 the results of Loeb just cited. If now the toxicity of a 

 salt is dependent upon the amount absorbed, as Ostwald has 



32, Loeb, J., The dynamics of living matter. New York, 

 19C6. Page 49. 



