92 IOWA ACADEMY OF SCIENCES. 



of a considerable quantity of ice used in Sioux City. The 

 specimen for analysis was taken at the combination bridge 

 on the Iowa side, May 27, 1901. The specimen for the 

 determination of the suspended matter was taken Decem- 

 ber 14, 1901. If it had been taken on the first date the 

 suspended matter would, undoubtedly, have been con- 

 siderably greater. 



Suspended matter ^^^• 



Total solids ^2^- 



Loss on Ignition 



Nitrogen as free ammonia ^^^ 



Nitrogen as albuminoid ammonia 0'* 



Nitrogen as nitrates 4.000 



Nitrogen as nitrites Trace 



Chlorine ^^ • ^ 



Oxygen consuming power ^-^^ 



The Floyd river flows south through the eastern portion 

 of the most populated portion of Sioux City, by the pack- 

 ing houses, and empties into the Missouri river where it 

 turns to the south. It receives a great deal of contamina- 

 tion from the starch plant above the city and several small 

 manufacturing plants upon its banks, the sewage from a 

 large part of the business district, and the filth from the 

 Armour and the Cudahay packing houses and the Sioux 

 City stock yards. The water during the summer becomes 

 very foul, so much so, that it is a nuisance to that part of 

 the city through which it flows. 



From the Seventh Street bridge to its mouth, a distance 

 of about one mile, it has a fall of about one inch. It 

 empties at right angles into the Missouri, from which dur- 

 ing several months of the year it receives the back water, 

 which extends up the river to the distance of one and one- 

 fourth miles to the Floyd Flour mill dam. At other times 

 when the wind is in the south the surface filth is kept from 

 flowing out. Under any conditions the current is not 

 sufficient to carry out the filth. When the back water 

 frum the Missouri flows out, which occurs once a year, a ^ 

 partial cleansing takes place. fli 



The city is preparing to straighten the channel of the ' 

 Floyd so that it will empty into the Missouri toward down 



