Nitrates in the Soie. 5 
presence of black alkali. This is not to be wondered at; in the 
first place the color of the surface soil is suggestive of the name 
and in the second place the bad effects upon vegetation which are 
associated with this color, lead the average man to attribute the 
cause of this to the only agent with which he is familiar, and which 
is believed to be adequate to produce this effect, namely, black 
alkali or sodic carbonate. Another reason which has apparently 
justified this inference in regard to the presence of sodic carbonate 
is the fact that the soil when moistened with an acid effervesces; 
this is due to the presence of calcic carbonate or marl, a form of 
limestone, and is not a proof of the presence of sodic carbonate. 
The appearance of a white coating or efflorescence on the sur¬ 
face of the soil indicates, with us, the presence of the sulfates of. 
lime, magnesia, and soda in the soil and usually an excess of water. 
The excess of water may be very injurious but these alkalis do not 
do any serious damage. These brown spots may or may not occur 
in association with the white alkalis. The intimate association of 
the two is so rare that we may state that they present distinct oc¬ 
currences. When they occur in the same piece of land, they usually 
occupy distinct areas, the brown being on higher ground than the 
white where there is a less abundant supply of water. 
Concerning the effects of the brown spots there is but one 
testimony, i. e., that nothing will grow. It is common to hear the 
expression that the white alkali is not bad but that the black is 
ruinous. We have had occasion to see the effects of it in many 
places, especially about Grand Junction, during the past season, 
the summer of 1909, when many apple trees and some shade trees 
succumbed to its influence. The effect that it produced was a 
burning of the leaves beginning at the tips, then extending along 
the edges till the whole leaf was brown. Sometimes only a few 
limbs on the tree were attacked in this way but very often all of 
the leaves were attacked and the tree was killed. I saw a great 
many apple trees killed during the summer of 1909 in this manner. 
I know of one orchard from which no trees have been removed 
this—the spring of 1910—from another 200; and in another more 
than 200 have been removed or are dead. There are many orchards 
in which a few trees, from one to twenty or more, have died. Fur¬ 
ther, there are young orchards in which the trees have refused to 
live. I recall several pieces of land which have been reset to or¬ 
chard, peach, apple and pear several times, as many as eight accord¬ 
ing to my information, and many of the trees are dead at this time. 
The condition indicated by the brown color affects both young and 
old trees. None of the trees alluded to above, as having been 
pulled up, were less than 14 and some of them were 27 years old. 
Some of these trees were nearly two feet in diameter and had 
