IOWA ACADEMY OF SCIENCES. 91 



The experimental work described in the following pao-es 

 was done by Mr. C. F. Eberly, except where otherwise 

 stated. Leffman's Manual of Water Analysis was used 

 as a guide in the work, with frequent references to 

 the original literature, or abstracts of the same The 

 results are given in milligrams per liter, except in the 

 anabasis reported by Professor Pope. The analyses made 

 by Prof. Floyd Davis were reported in grams per U. S 

 gallon, but have been converted into the milligram system* 

 Duplicate analyses were made in every case and the aver- 

 age of these reported. 



The Bi', Sioux river flows along the western boundary of 

 bioux City about four miles west of the most thickly 

 populated part of the city. Along its eastern bank are 

 located a few manufacturing plants and Riverside park It 

 receives practically no sewage from the city. It receives 

 the back water from the Missouri during the months of 

 May, June and July. This back water extends a number 

 miles up the river and at the park rises to the height of 

 about eight feet above the ordinary level. At other times 

 it has a good current. 



The greater portion of the ice consumed in Sioux City is 

 obtained from this river. The specimen for analysis was 

 taken at Riverside park, November 28, 1901, when the 

 river was at its normal height. The water was slightly 

 turbid but It was not filtered before making the analysis. 



Total solids 



Loss on ignition -' 



Nitrogen as free ammonia ... . n'loc 



JNitrogen as albummoid ammonia 280 



Nitrogen as nitrates ' ' ^ 



Nitrogen as nitrites ^t 



(^,, None 



Lhlonne 



,. 9.936 



Uxygen consuming power 2 m i 



The Missouri river forms the southern boundary of the 

 greater part of Sionx City. It has a very swift current 

 which carries with it a large quantity of sediment, 

 especially when the riyer is high during the summer 

 months, which is said to ho due to the melting of the snow 

 in the upper portion of its basin. The Missouri is a source 



