The: Fixation oe Nitrogen. 5 
definite measure of its effects it was stated: “I know of one 
orchard from which no trees have been removed this—the spring 
of 1910—another from which 200, and still another from which 
more than 200 trees have been removed or are dead.” 
I gave what appeared to me a justifying reason for considering 
orchard trees rather than some other crop. My reason was essen¬ 
tially this, that the effect, in the case of the apple tree in particular, 
is so wide-spread and disastrous that no one conversant with the 
facts can doubt the existence of a very serious evil, and inasmuch 
as our orchards both old and young received almost constant atten¬ 
tion and care, I wanted to appeal to both the knowledge and in¬ 
terests of the people, as I realized that I was setting forth rather 
startling facts, and if the people did not believe in the existence 
of the evil any explanation of the cause would be nothing more 
than an appeal to their imaginations. That I was justified in this 
course is fully shown by the doubts entertained by persons who 
are not ranchmen and orchardists but men of education, experience 
and mature judgment, some of whom when asked for an opinion 
have reserved their judgment on the ground that they had never 
seen such conditions as were described. 
It was not my intention in either of the bulletins previously 
issued on this subject to venture upon the question pertaining to the 
possible influence of the excessive formation of nitre in the soil upon 
any of the general crops but it seemed wise to make some tentative 
statements regarding this feature of the question and the beet crop 
was mentioned as one which had, possibly, already shown the effects 
of a continuous and, in the aggregate, excessive supply of this 
salt. Of course, such a bold suggestion would meet with doubt if 
not with less kindly treatment. I purposely held close to demon¬ 
strable facts, i. e., the presence of unprecedented quantities of 
nitrates, sometimes confined to small areas but often extending so 
as to involve eight, ten, twenty or even forty acres, or the death of 
many apple trees scattered over a large territory, all attacked and 
dying in a similar manner, or the increasing nonproductiveness of 
the land till total barrenness ensued. I suggested as a cause for the 
accumulation of these nitrates the action of certain groups of 
bacteria only after I had considered every other source which might 
prove sufficient to explain all of the facts. While the facts adduced • 
as the basis of this claim may be open to some objections, I believe 
that we shall be able to show that it is a fact that the nitrates are 
formed in situ, but I shall leave the explanation of this fact and 
the questions, whence comes the energy; are the azotobacter species 
alone responsible for the fixation and nitrification or do other groups 
of bacteria play a more important part than the azotobacter in con¬ 
verting the nitrogen into nitric acid, for others to solve. 
The task which I set myself is to show that the nitrate is 
