The concluding volume of the Principles and Practice of Agricultural
Analysis has been written in harmony with the plan adopted at the
commencement of the first volume. In it an effort has been made to
place the analyst or student _en rapport_ with all the best methods of
studying the composition of agricultural products. During the progress
of the work the author has frequently been asked why some special
method in each case has not been designated as the proper one to be
used. To do this would be a radical departure from the fundamental
idea of the work; _viz._, to rely on the good judgment and experience
of the chemist. It is not likely that the author’s judgment in such
matters is better than that of the analyst using the book, and, except
for beginning students pursuing a course of laboratory instruction, a
biased judgment is little better than none at all. For student’s work
in the laboratory or classroom it is probable that a volume of selected
methods based on the present work may be prepared later on, but this
possible future need has not been allowed to change the purpose of
the author as expressed in the preface of the second volume “to
present to the busy worker a broad view of a great subject.” For the
courtesy and patience of the publishers, for the uniformly commendatory
notices of the reviewers of volumes one and two, and for the personal
encouraging expressions of his professional brethren the author is
sincerely grateful. He finds in this cordial reception of his book a
grateful compensation for long years of labor. The plates of the first
edition of the three volumes have been destroyed in order to insure a
re-writing of the second edition when it shall be demanded, in order
to keep it abreast of the rapid progress in the field of agricultural
chemical analysis.