Nitrogen Fixation 45 
tion that nitrates injuriously affect the quality of the beet when 
present in large quantities, then beets grown in such soils ought to 
be very poor, not necessarily in crop but in quality. I have seen 
beets planted in ground so rich in nitrates that when the water 
soluble residue, amounting to 4.6 per cent of the air dried soil, was 
treated with ferrous sulfate and sulfuric acid the red brown vapors 
of N 0 2 could be seen filling and even flowing out of the test tube. 
This sample of soil was taken October 11, 1909. There was only 
here and there a straggling beet in this portion of the field. Ad¬ 
joining this was an area of big green tops with medium sized, 
white, brittle beets. The sugar content and coefficient of purity 
were not determined. This study has probably only been begun. 
Plate V illustrates a beet field, not the-one referred to above. 
The amount of nitric acid in this soil is very high, as high as that 
of some of our orchard soils in which it is measured by the ton per 
acre foot of soil. I have tried to give facts enough to place the 
occurrence of these very large quantities of nitrates in our soil? 
beyond question. I have endeavored to give reasons for believing 
that the nitrates are not derived from the shales which are often 
popularly assumed to be the source of this “black alkali” or nitre. 
I have given one instance of its serious effect upon orchard trees 
but hold back other features of its influence upon our agriculture 
for further study. 
Unaided by bacteriological investigation, until within the past 
year, I had to content myself with a theory in regard to the source 
of these nitrates. I found a few things common to these occur¬ 
rences. They were all so situated that while the water was not 
excessive there was an adequate and constant supply of it. The soils 
are almost uniformly comparatively poor in nitrogenous matter and 
there is always an abundance of carbonate of lime. We have some 
occurrences of these nitrates in the northern parts of the state but 
they are always in places where we have comparatively even, high 
temperatures for goodly periods at a time. These are favorable con¬ 
ditions for the development of a bacterial flora. I believed that in 
these places the flora was a nitrogen fixing one. I presented these 
views to Professor Sackett and have been fortunate enough to 
obtain his aid in carrying the investigation further on bacteriologi¬ 
cal lines. Considerable preliminary work has already been done 
and we purpose to continue the work in the field and in the labora¬ 
tories even beyond the limits which we now see and there is much 
work within these limits. Professor Sackett and I have already 
gathered samples from several sections of the state. All of the 
samples so far examined are from localities that I have known for 
several years and in one sense are from promising places, i. e., from 
sections rich in nitrates. Some of the samples are unfortunately so 
