Ward. — Elimination of Stream Pollution in New York 17 



do not believe it possible for the chemist to experiment with 

 fish alone through a brief period, and establish the harmlessness 

 of wastes. I think there has been an abundant amount of scientific 

 investigation to show that many wastes are harmful in the worst 

 possible sort of way, tho on short experimentation these sub- 

 stances seem to exercise no particular influence over the fish. 

 To show you how insignificant, how very small an amount of a 

 chemical may be when it operates at a long distance, let me cite 

 to you a specific instance. The city of Lincoln, Nebraska, uses 

 water for drinking purposes from deep wells. At one time there 

 was typhoid fever in the city. It was suggested that in some 

 way these wells had become contaminated, and the city started 

 at once treating the water with chlorine in very small amounts. 

 We had in the zoological laboratory a big aquarium room in 

 which were kept a lot of cultures of microscopic organisms. That 

 room was supplied with city water. It was at a distance of several 

 miles from the point where the water was treated. We were 

 unable by tests to determine the presence of chlorine in the water 

 and yet these microscopic organisms promptly died off, and it 

 was impossible to reestablish the cultures; they would not live 

 in that water. 



Now the food of the fish consists of or is dependent on those 

 organisms. The small fish might eat them themselves. Larger 

 fish would eat an intermediate sized organism that ate this smaller 

 type. The destruction of that food would drive away any fish 

 just as directly as if the fish themselves had been affected by it; 

 and I am not here to contend that the fish are not affected by it, 

 although the degree of influence on the fish was so small that it 

 could not be told by the type of experimentation which has 

 ordinarily been tried. 



In the next place I want to call your attention to the fact of 

 changes which are making very serious modifications of natural 

 conditions, changes that are well-illustrated in New York state 

 and also at many other points. We are beginning to make over 

 natural water systems into a series of ponds. When we put up 

 dams, in what was formerly a rippling stream coming down over 

 the rocks, absorbing large quantities of oxygen, and undergoing 

 changes that tend to purify it and put it in splendid condition, 

 there is substituted for it a deep pond almost without movement 



