30 



A series of combinations of Cu(NC3)2 with KNO, v/as 

 carried out in which the constant concentration of the 

 potassium salt, C.C5m, was used in combination with Gu(NC3)o 

 in concentrations ranging from 0.00C2m to 0.01m. The spores 

 germinated in concentrations up to and including C.002ra of 

 the copper salt. In the last mentioned concentration the 

 form of germination was quite similar to that found in a 

 C.0CCC4m solution of the copper salt alone. Thus in a sol- 

 ution containing KEC3 at a C.C5m concentration and Cu(K03)2 

 at a C.C02m concentration (a molecular ratio of 25K to ICu), 

 the toxicity of the copper salt is decreased to a magnitude 

 only one fiftieth as great as is that shown by this concen- 

 tration of the copper salt alone. 



The results of the three series of combinations of 

 copper nitrate with calcivun nitrate which have been de- 

 scribed are summarized below, together with certain other 

 data which are about to be considered. 



