3 4 Colorado Experiment Station 
are both few and small. Large quantities of this salt, or brine, of 
course will kill most kinds of vegetation. These big quantities which 
would make it a serious thing for us are not found in our alkalis. 
I recall one place where it is very abundant in what we would desig¬ 
nate alkalis, but to insist on considering this would be foolish, because 
it is only in a comparatively small area and its source is evidently from 
a salt spring at the head of the stream along which this salt is found. 
In early days they boiled salt at this point. While it does not occur 
in injurious quantities, it occurs everywhere. 
Calcic sulfate is very abundant in our soils and, as it is soluble 
in water, it comes to the surface with the other salts in solution and 
crystallizes out, forming a part of our alkalis. Sometimes it forms a 
very large part of them. This compound in very large quantities is 
dangerous as I have pointed out in the case of apple trees, but ordi¬ 
narily it can be neglected unless it forms a hard-pan, when it is very 
objectionable, both because it forms a hard-pan and because it may 
become injurious. 
As I may not come back to this point, I shall digress to state that 
the most regrettable results that I have seen in this connection are 
its effects on orchards. The trees may do quite well for eight or ten 
years, but at about this period several difficulties show themselves. 
The trees cease to grow and often turn yellow. In such cases it will 
generally be found that the root system has been prevented from de- 
A^eloping and is inadequate to properly nourish the trees and the food 
that these roots furnish to the growdng parts of the trees may be and 
probably is an improper food, i.e., is poisonous, not necessarily in a 
virulent degree but so much so that the trees become unthrifty. 
Calcic chlorid is not very injurious and does not often occur in 
our alkalis in any considerable proportion. There are a few places,, 
however, where it may be said to be very abundant. These occur¬ 
rences have no significance from an agricultural standpoint, for the 
places where I have found it most abundant would be unproductive 
if it were absent, due to other conditions. I have no idea at all how 
much of this substance it would require to make a soil unfriendly to^ 
vegetation. I recall an orchard in fairly good condition in which the 
soil contained enough of this substance to keep the surface wet enough 
to make it so dark in color that one could easily pick out these spots. 
I do not know what effect this condition had upon the orchard. At 
the time I visited it there was no marked difference in the size and 
vigor of the trees in these spots and in the condition of those growing 
outside them. As the condition of the whole orchard was only fair 
and I made no further study of it than the examination of a single set 
of samples of soil that I took on this visit, I cannot state that this calcic 
