The Soil. 
7 
A surface well, 28 feet deep, yielded water giving a large resi¬ 
due, of which these salts formed 74 per cent., as follows: 
Calcic sulfate__15.206 percent. 
Magnesic sulfate_29.059 per cent. 
Sodic sulfate_29.865 per cent. 
An artesian well, supposed to tap a water bearing Dakota 
sandstone and having a depth of 845 feet, furnished a water carry¬ 
ing 79 grains of total solids in each imperial gallon, of which 83 
per cent, consisted of these salts, as follows : 
Calcic sulfate_12.036 percent. 
Magnesic sulfate_10.473 percent 
Sodic sulfate_60.758 percent. 
It is evident, not only from observation, but as is also indicated 
by such figures as these, that it is not at all necessary for the agri¬ 
culturist to question in regard to the immediate source of the salts 
included under the general term alkali. They are so abundantly 
present in the rocks and waters, even in waters from considerable 
depths, that there is no need to seek further for their supply. The 
questions relative to their more remote origin and how it happens 
that the shales and even the sandstones are impregnated with these 
salts can be left to the geologist without serious inconvenience in 
studying the questions with which our agriculture has to deal. 
They are here, and in cases where the drainage of any larger area 
accumulates in a small basin, alkali salts will be brought together 
and under proper conditions will appear as an incrustation. This 
does not take place unless the water plane is at a less distance from 
the surface than that through which capillarity can raise the water 
in the particular soil. This was the case in the soil in question, the 
incrustations accumulating to a maximum thickness of upwards of 
one half inch. The incrustations being most marked in early sum¬ 
mer, but also during the winter when the condition of the weather 
was favorable. 
Relative to the origin of such quantities of sulfates in these 
rocks and soils, the possible supply is abundant, for throughout the 
mountain masses we find sulfids disseminated everywhere and we 
have an almost inexhaustible source of sulfuric acid for the forma¬ 
tion of alkali in the gypsum which is so abundant in our Jurassic 
and other formations. 
THIS STUDY LARGELY A MINERALOGICAL ONE. 
. §11. It is to be understood that throughout this bulletin the 
term soil is used sometimes to mean all of the factors conducing to 
make up the unit which is expressed by this term; at others in a 
much narrower sense, meaning to include only a part of the same. 
