TABLE OF CONTENTS. 



Page 



Abstract 3 



Introduction 5 



Organism 14 



Methods 18 



Experimentation 23 



Toxicity of salt combinations 24 



Calcium, magnesium and potassium .... 24 



Copper 27 



Lead 41 



Zinc 50 



Aluminum 52 



Nickel 55 



Toxicity of single salts 56 



General discussion 67 



Tita 76 



