Alkalis In Colorado 
9 
we look for them, at least we find chlorin, in small amounts it is true, 
but the mass of our mountains is tremendous and that of the still un¬ 
decomposed fragments of these rocks and minerals in the soil is be¬ 
yond our conception. So, without appealing to the sea water and 
salt deposits occurring in various parts of the world, the aggregate 
supply of chlorids is not only exceedingly great but their distribution 
or occurrence is universal, our great bodies of fresh water are not 
free from them and the beds of our ancient fresh-water lakes contain 
them. The flow of the waters from the land to the sea is carrying a 
constantly renewed burden of these salts, especially the sodic and 
magnesic chlorids and the magnesic sulfate, to the sea. The reason 
that we have such quantities of sodic sulfate, sodic carbonate, mag¬ 
nesic sulfate, calcic sulfate, and the chlorids in our soils is not that 
they have produced more of these salts than other soils but because 
the water supply has not been big enough to carry away the products 
of its own action. The insufficiency of water is fully indicated in our 
term “semi-arid climate”. 
Enormous Quantities Contributed By Rivers 
The reader for whom this bulletin is really written possibly has 
never thought of the different kinds of work, or the amount of it, 
that the streams of our mountain-sides are doing. He knows that the 
gaps in our hog-backs of today are places through which streams may 
flow, sometimes only during heavy rains or continued wet spells. He 
is familiar with the canyons of perhaps a score of little streams in 
the mountains. He may sometimes wonder how the deep gashes 
through the solid rocks may have been cut, but he probably never 
thinks of the burden of material carried by the clear, cool water that 
he drinks with great pleasure. 
The Cache la Poudre 
The Cache la Poudre River, which flows through the mountains 
of Northern Coloardo, is a comparatively small stream. Its flow 
averages about 600 second feet. The average fall of the river for the 
first 50 miles of its course, is 80 feet to the mile. In many places it ' 
is a mass of foaming water just as some other mountain streams are. 
This impresses us with its ability to wear the rocks which are already 
worn smooth and the rock walls bear witness, by their polished faces, 
to the action of this process in the past. We do not wonder that the 
boulders are worn and that the fine sand has in so large a degree been 
carried away. But that this same limpid water carries an unseen 
burden and is doing a continued work in changing the very substance 
of the rocks and carrying them away does not impress itself on the 
mind of many of us, and yet this little river with an average flow of 
600 second feet, whose waters carry approximately 3 grains of total 
