OF THE NORTHWEST. 



by the Lower Magnesian Limestone, and that of the district further south, in Wis- 

 consin and Iowa, where the Upper Magnesian Limestone is the surface rock ; the 

 reason is, both rocks are so nearly alike in chemical composition, that they undergo 

 similar changes by atmospheric agencies. There is scenery on the Upper Iowa 

 which is almost a fac-simile of views on the Little Makoqueta River in the Dubuque 

 District, where the rock is the Upper Magnesian Limestone. Both regions present 

 a combination of rural beauty characteristic of a considerable portion of the Upper 

 Mississippi. It is such as fixes itself strongly on the feelings of its inhabitants, and 

 tends to endear to them the spot of their nativity. 



The soil derived from the decomposition of the Lower Magnesian Limestone is 

 usually of excellent quality ; rich, as well in organic matter, as in those mineral 

 salts which give rapidity to the growth of plants, and that durability which 

 enables it to sustain a long succession of crops. The analysis of a soil,* 

 taken from a region of this formation on the Eau Gallee, gave 8-2 per cent, of 

 organic matter, ll - 2 per cent, of salts, 77*1 per cent, of insoluble silicates, and 0*8 

 per cent, of carbonate of lime : this is 7 - 2 per cent, more salts, and 0 - 79 per cent, 

 more carbonate of lime than the Chippewa soil derived from Formation 1. 



* Analysis of soil taken from the region of F. 2, on the Eau Gallee. 



Water, . . . . . . 2-50 



Organic matter, ....... 8-20 



Silicic acid, dissolved by chlorohydric acid, .... 0'04 



Carbonate of lime, ....... 0-80 



Magnesia, . . . . . . . 0-32 



Oxide of iron, ........ 2-68 



Alumina, dissolved by chlorohydric acid, . 3-04 



Alumina, dissolved by sulphuric acid, ..... 1-00 



Alkalies, . . . . . 0-08 



Phosphates of lime and iron, ...... 0-01 



Insoluble silicates, ....... 77T0 



Inorganic acids, combined with above bases, and loss, . . 4-23 



100-00 



