Alkalis In Colorado 
13 
the cutting off of the water furnished by the root hairs. This view 
is further strengthened by the deportment of vigorously growing 
trees located in ground rich in nitrates. I have seen the foliage wilt 
and the trees die without tip burning. I took this to be caused by the 
sudden cutting off of the water supply. The solution in this case con¬ 
tained large amounts of nitrates. May a sufficiently strong solution of 
other salts possibly act in a similar manner ? I tried this with ordinary 
kitchen salt of which I put 25 pounds around a four-year-old apple 
tree and threw up a little dike around the area and turned in the ditch 
water. No injury resulted. This experiment served its purpose very 
well, but in this connection it only shows that 25 pounds of salt did 
not furnish a sufficiently strong solution to do any damage. 
SODIC CARBONATE ESPECIALLY HARMFUL 
The next most injurious compound in these alkalis is sodic car¬ 
bonate. When this salt is present and is brought into solution it acts 
like caustic soda or a weak solution of lye. It attacks the tissues of 
the little plants and sometimes big ones and kills them. Another thing 
it does is to cause the soil to become hard, so hard indeed that one may 
be surprised that plants can grow at all. I recall such a crust, from 
4 to 6 inches thick, so hard that we used a mattock to cut through it. 
Under this crust the soil was open, even sandy. The presence of this 
compound is very general, as we would expect it to be, for it is one 
of the first products of the breaking down of the felspars which occur 
in every fragment of granite, schist, or igneous rock and also in many 
sandstones. It is from such rocks that our soils have been derived, 
at least in far the greater part, and these felspars occur practically 
everywhere, so we have good reason to expect more or less of this 
carbonate everywhere and we find it very generally in drain-water 
and in our alkalis in small quantity. 
The magnesic sulfate and chlorid in pure solutions are more detri¬ 
mental to vegetation than the carbonate of soda, but they don’t occur in 
the form of pure solutions, nor are they bottled up in separate corners 
of the soil. Even the soil itself very often has a great deal to do in 
determining what the compounds will do. 
The most abundant constituent of our alkalis is the sulfate of 
soda, commonly known as Glauber’s salt. This salt is fortunately 
not very injurious, even in pure solutions. It is scarcely corrosive at 
all, as many ranchmen in Colorado have had ample opportunity to ob* 
serve, for the white coatings that in many places covers the surface of 
the land, in some sections for many square miles in one continuous 
body, consist very largely of this substance. 
Sodic chlorid, ordinary kitchen salt, does not occur in any large 
quantities in our alkalis. The areas in which I have found much salt 
