RESUME 
The occurrence of “brown spots” has been complained of from time 
to time for years past. The first ones that I saw, to recognize as being 
rich in nitrates, were in uncultivated land in the extreme southern part 
of the state. These were round or eliptical spots, smooth and shining on 
the surface, and had an almost black color. They were wholly destitute 
of vegetation. The rocks forming the neighboring mountains were gran¬ 
ites and schists. The strata underlying this soil were sands and clays 
of lacustrine origin. The waters of this section are exceptionally pure 
and are acid in character, i. e. the most of them, surface waters excepted, 
contain more acids than are necessary to combine with the bases; silicic 
acid is usually in marked excess. Other occurrences are in Cretaceous 
and still others in Triassic areas. Some of these brown spots are small 
and isolated, in other cases they have coalesced and cover comparatively 
large areas—twenty, thirty or more acres from which the vegetation has, 
in many cases, been exterminated. The barrenness of these spots has not 
in all cases been permanent, in other cases it has been very persistent. 
These spots in 1910 and 1911 were very common in some sections of the 
state, and but few cultivated sections in the state, with which I am 
familiar, are entirely free from them. We have some marked cases of 
their occurrence in this immediate neighborhood which is within forty 
miles of the northern boundary of the state, and I have seen them almost 
on the southern boundary line. They also occur in the extreme eastern 
and western parts and at various altitudes up to 7500 feet. 
Their appearance is peculiar, usually the soil is mealy and from a 
light brown to almost black in color, varying somewhat with the soil. 
That they have spread during the past seven years is evident from the 
statements made concerning the damage done. Lands that were con¬ 
sidered desirable five years ago are now of little value and where four 
years ago, only an acre or two was known to be affected, many acres are 
now involved. These spots are not confined to any particular variety of 
soil or to any particular geological horizon. They occur on well drained 
land as well as on land that contains an abundance of water. In some 
cases the muddy condition of the land seems to be a result rather than 
the cause of this condition. 
These spots are characterized by their brown color. In some 
instances they appear smooth and shining, but usually they are soft under 
the foot, mealy, and at a little distance give the impression that they are 
moist. In orchards where oil has been used for heating one might readily 
take small spots as due to spilled oil or contrariwise, an oil spot for a 
nitre spot. The amount of water-soluble salts in the surface portions 
of these spots, varies exceedingly. By surface portion, I mean all depths 
up to three inches. These spots do not, as a rule, show efflorescences 
w r hich is characteristic of alkali spots. There is sometimes an incrusta¬ 
tion. The maximum amount of water-soluble found in a selected sample 
oLthis brown surface incrustation amounted to 22.5 percent, of which 29.1 
