544 



THE GLACIAL LAKE AGASSIZ. 



12. Water from Lake Superior, collected at Grand Marais, Minn. 



Ingredients dissolved in the water. 



Silica 



Alumina and oxide of iron. 



Carbonate of lime 



Carbonate of magnesia 



Carbonate of lithia 



Carbonate of potasli 



Nitrate of potash 



Nitrite of potash 



Carbonate of soda 



Sulphate of soda 



Chloride of sodium 



Total 



Parts per Percent- Grains per 

 million. age. gallon. 



0.5 



Traces. 



30.8 



9.1 



Traces. 



1.9 



0.2 



(') 



0.5 



0.6 



2.1 



45.7 



67.4 

 19.9 



4.2 

 0.5 



1.1 

 1.3 

 4.5 



100.0 



1. 79656 

 . 53080 



. 11083 

 . 01167 



. 02917 

 . 03499 

 . 12249 



2. 66568 



> Minute traces. 



Iodine and bromine, absent; phosphates and borates, absent. The test 

 Avith permanganate showed 0.35 parts oxygen consumed by organic matter 

 per 1,000,000 water. 



Hardness, 3.5 degrees, so low amount being less than the average of 

 "soft" well and spring waters. 



This analysis of the very pure water of Lake Superior (perhaps even 

 more remarkable for its small content of organic than of mineral matter) 

 is presented for comparison with the waters of the Red River Valley. It 

 contains less than one-fourth as much mineral matter, and only slightly 

 more than this proportion of organic matter, as compared with the water 

 of the Upper Mississippi River at Brainerd. These proportions, in compar- 

 ison with the water of Big Stone Lake, are respectively one-twelfth and 

 about one-fourth. The Red River at Fergus Falls has about four and a 

 half times as much mineral matter as Lake Superior, and four times as much 

 organic matter; but at St. Vincent these proportions are increased respec- 

 tively to 6 and 10, and the former is still further raised to 11 at the mouth 

 of the Assiniboine and the city of Winnipeg. 



The artesian water at Carman has ten times as much mineral matter 

 and two and a half times as much organic matter as Lake Superior, and 

 these proportions for the Jamestown artesian well are respectively about 



