28 



THE LIFE OF DEVILS LAKE 



CHEMISTRY 



The chemistry of Devils Lake Avater naturally varies with the 

 variation in the lake level. A large number of analyses have been 

 made in different years by different chemists. Many of them arc- 

 partial, but there is a good series, which is complete for all the 

 most important constituents of the water. The methods employed 

 have been, in general, those recommended bj- the American Public 

 Health Association. The results show an increase in salt concentra- 

 tion, accompanying the decrease in lake level, from 8471 ppm. in 

 1899 to 15210 in 1923. This chemical change is, as will be seen 

 later, probably the most important factor in determining the 

 changes in the inhabitants of the lake. The analysis (table 3) 

 shows the character of Devils Lake water to be typical of other 

 brackish water lakes of the interior. 



The salt content of surface and bottom layers is alike, but some 

 differences e.\ist between different parts of the lake, dependent on 

 the scanty supply of fresh water drainage at one or two points, in- 

 flux of sewage, and probably to some extent also on other less 

 obvious factors, such as temperature, depth, kind and amount of 

 organic matter in the ooze and kind and number of organisms pres 

 ent in the water. 



