Alkalis In Colorado 
ii 
by different agents. Nitrates in very small quantities are often pres¬ 
ent in well-waters, seldom present in river-waters and are not com¬ 
ponents of ordinary minerals. They have long been known to be 
present in small quantities in the surface portions of rocks and have 
been considered as factors in their weathering or the changes taking 
place in them. They have also been found in caves, but wherever 
they have been found they have been considered as the products of 
living organisms. It is only within recent years that these salts have 
been noticed in the soil in sufficient quantities to become detrimental. 
Their presence in some California alkalis was noticed by Hilgard and 
their origin attributed to the oxidation of the nitrogen found in or¬ 
ganic matter. This is without doubt correct, but Prof. Hilgard did 
not account for the organic matter. I do not recall his making any 
definite statement concerning the organic matter from which these 
nitrates are supposed to have been formed. The nearest to a definite 
statement pertaining to this subject is made on Page 68 of “Soil”, 
where he states: “In the plains of the San Joaquin Valley, spots strongly 
impregnated with niter are found, especially under the shadows of isolated 
oak trees, where cattle have been in the habit of congregating for a long 
time”. 
The conversion of organic nitrogen, such as exists in the ex¬ 
creta or in the bodies of animals and in the tissues of plants, into 
nitric acid or nitrates is well established and has been accepted for 
about 30 years. I think that Prof. Hilgard considers such to be the 
source of the nitric nitrogen referred to in a preceding sentence, in 
which he states that the nitrates form at times as much as one-fifth 
and even more, of the entire mass of alkali salts. “In one case the 
total amount in the soil has been found to reach two tons per acre 
with an average of twelve hundred pounds over ten acres”. This, 
though it is a large quantity, is not big compared with the quantities 
of these salts that we have found in some of our Colorado soils. This 
is enough to say on this phase of the subject in this place. 
The nitrates found may be either the nitrate of lime, of magnesia 
or of soda. It is a matter of accident, apparently, which one of the 
three occurs. There is a question whether these belong to the alkalis. 
I think that they should be included. They constitute an important 
part of the soluble salts in many of our lands, and more than this, we 
can trace very serious damage to them. Considered from the stand¬ 
point of their source, including them with the alkalis seems scarcely 
justifiable, on the other hand their presence in very notable quantities, 
their solubility and their deleterious action on vegetation are in my 
opinion sufficient reasons for considering them in this connection. 
Calcic chlorid is occasionally met with in large quantities and is 
probably formed by the interaction of other “alkali” salts. 
