106 life's beginning on the earth 



Loeb's investigations have shown that the purer the salt 

 solution the more harmful it is to the fish. Most harmful 

 of all is a solution of carefully purified sodium chloride in 

 pure distilled water. If we add to the sodium chloride just 

 one of the numerous other salts present in the ocean in small 

 quantities, the fish lives much longer. 



^A 



A B CD 



P'ig. 30. Growth of the Roots of Wheat in Salt Solutions of 



Varying Composition 



(Natural size) 



A. "Complete" salt solution containing all the different saline com- 

 ponents of the ocean in the same relative amounts as in the sea. 



B. Solution containing only table salt (sodium chloride) and lime salt. 



C. Lime salt solution only. 



D. Table salt solution only. 



A seed can develop only in solution which contains all the oceanic salts. 

 A solution with only one of its components is definitely harmful. 



This experiment shows that all the various salts which are contained in 

 the ocean are necessary for the development of life in any form, even up to 

 the present day. 



The chemically pure table-salt solution is detrimental, 

 not only to fish, but likewise to any other living creatures, 

 including plants. Wheat germs germinate poorly in a pure 

 salt solution, whereas they develop abundantly in a solu- 

 tion containing all the salts of the ocean or at least some of 

 them (Fig. 30). Moreover the common food of men and 

 animals contains salt but never pure salt; common tabic salt 



