288 American Fisheries Society 



residue from 'the straw-board works. It was found that the results from 

 the straw-board works residue were a little better than from the applica- 

 tion of barnyard manure, ton for ton. It also brings humus to the soil ; 

 that is not taken into consideration in these values. 



Mr. J. G. Johnson, Riverside, R. I. : Is that clay found on a 

 certain farm in Ohio? 



Mr. Travers : The only place I know where it is found is on Kibler 

 farm, Pickaway County, Ohio. The Geological Survey says that in 

 only three places in the United States are deposits of this kind found. 

 Two are in \ew Jersey and one is on the Kibler farm. I do not quite 

 agree with that, though. The first two carloads were shipped last week, 

 one to the Loudenslager Company, of Columbus, and the other to the 

 American Tinplate Company, of Cambridge. The day after a car 

 arrived, the superintendent told me that it was working fine and giving 

 far better satisfaction than the old treatment of calcium oxide and sul- 

 phate of iron. 



Mr. Johnson: Is the supply of clay unlimited? 



Mr. Travers : There are about 500,000 tons, as near is I could judge. 

 It will not last very long when it comes into general use. 



Mr. Titcomb: What does it cost per ton to produce? 



Mr. Travers: It lies right on top of the ground; about two dollars 

 a ton, I suppose. 



Mr. Radcxiffe : Then there is danger of exhaustion of this source 

 of clay supply, is there? 



Mr. Travers : There really is, I believe. The matter is of so much 

 importance that I think the National Government should take hold of it 

 and keep private individuals from grabbing up the raw deposits and 

 charging an exorbitant price, thus nullifying the good work which may 

 be done through its use. 



Mr. William F. Wells, Albany, N. Y. : There is a good deal of 

 misunderstanding about the whole subject of stream pollution, and I 

 should like to bring out one or two of the fundamental characteristics 

 of pollution. It is usually necessary in treating wastes to take out most 

 of the solid suspended matter before discharge into a stream. The 

 suspended matter settles out and forms deposits which, as Mr. Travers 

 said, ferment and bring about a very foul condition in the stream. If 

 all the suspended matter is taken out the soluble organic substances are 

 left, and even a clear solution may still be very putrescible and cause 

 trouble when run into a stream. In other words, the question of putres- 

 cibility depends on the power of the soluble as well as the suspended 

 organic substances to absorb oxygen from the water. Any organic 

 material, of course, furnishes food for living organisms, the minute or- 

 ganisms being just as real as fish or other animals, and in the aggre- 

 gate they require a great deal of oxygen. For instance, if you take one 

 of these fluids and put into it a little methylene blue, it will be blue 

 today and colorless tomorrow, showing that the oxygen has been used 

 up, and if you put a fish in there, it will not live a minute, any more 



