16 
SOILS AND ALKALI. 
and the potash 7 cents, these elements being the “ trinity of 
excellence ” in any soil. A glance at the table will show 
that soil No. 8 contains the elements of plant food in the 
greatest proportion, and the notes accompanying it show 
that it is a rich garden soil that had been manured for 
experiments with sugar beets. Another important fact in 
connection with soils and fertilizers is that this plant food 
must be in a soluble or availo2)le form to do any immediate 
good to the crops. 
ALKALI SOILS OF COLORADO. 
The name alkali soils is applied, in the arid region, to 
all soils containing a large amount of mineral matter, 
usually occurring as a white powder or crust upon the sur¬ 
face. The first rain dissolves it and carries it into the 
watercourses and back into the soil, to rise again at the re¬ 
currence of dry weather. The rain that falls upon the 
soil may be divided into three parts: One part that 
rushes immediatelv off the surface, and causes the floods 
of rivers and small streams; another part that sinks into 
the earth and, after doing its chemical work of soil-making, 
reappears as springs, and forms the supply of streams and 
rivers, and a last portion that reaches the sea by subter¬ 
ranean channels. The amount of the rainfall that is car¬ 
ried off by the rivers has been estimated by Humphrey 
and Abbott, in the cases of the Mississippi and Ohio 
rivers, to be about one-fourth of that furnished by the 
rains; for the Missouri, 15-100. It is not far from the 
truth to say that about one-fourth the rainfall is car¬ 
ried off' by the rivers. The other three-fourths goes 
off* by evaporation and as subterranean water. A 
well is nothing but a hole in the ground a little below 
where the ground is saturated with water. Engineers call 
