Principles and practice of agricultural analysis. Volume 3 (of 3), Agricultural products

Transcriber’s Notes:

 Underscores “_” before and after a word or phrase indicate _italics_ in
    the original text.
  Equal signs “=” before and after a word or phrase indicate =bold= in
    the original text.
  A single underscore after a symbol indicates a subscript.
  Small capitals have been converted to SOLID capitals.
  Illustrations have been moved so they do not break up paragraphs.
  Antiquated spellings have been preserved.
  Typographical and punctuation errors have been silently corrected.
  The “CORRECTIONS FOR VOL. III.” listed at the end of the book have
    already been applied to the text by the transcriber.




              PRINCIPLES AND PRACTICE OF
                AGRICULTURAL ANALYSIS.

        A MANUAL FOR THE EXAMINATION OF SOILS,
        FERTILIZERS, AND AGRICULTURAL PRODUCTS.

        FOR THE USE OF ANALYSTS, TEACHERS, AND
          STUDENTS OF AGRICULTURAL CHEMISTRY.

                      VOLUME III.

                AGRICULTURAL PRODUCTS.

                  BY HARVEY W. WILEY,
    CHEMIST OF THE U. S. DEPARTMENT OF AGRICULTURE.

                      EASTON, PA.
                CHEMICAL PUBLISHING CO.
                         1897.

                   COPYRIGHT, 1897,
                  BY HARVEY W. WILEY.




PREFACE TO VOLUME THIRD.


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.

WASHINGTON, D. C.,

Beginning of January, 1897.




TABLE OF CONTENTS OF VOLUME THIRD.


                     PART FIRST.
      SAMPLING, DRYING, INCINERATION AND EXTRACTIONS.

     _Introduction_, pp. 1-3.—Methods of study;
     Scope of the work; Limitations of work; General
     manipulations.

     _Methods of Sampling_, pp. 3-13.—Vegetable
     substances; Animal substances; Preserving samples;
     Collecting samples; Grinding samples; Grinding
     apparatus.

     _Drying Organic Bodies_, pp. 13-36.—Volatile
     bodies; Drying ovens; Air baths; Drying in vacuum;
     Electric drying ovens; Steam coil apparatus; Drying
     in hydrogen; Drying in tubes; Drying viscous liquids;
     General principles of drying.

     _Incineration_, pp. 36-40.—Principles of
     incineration; Products of combustion; Purpose
     and conduct of incineration; German ash method;
     Courtonne’s muffle.

     _Extraction of Organic Bodies_, pp.
     40-57.—Object of extraction; Solvents; Methods of
     extraction; Extraction by digestion; Extraction
     by percolation; Apparatus for extraction; Knorr’s
     extraction apparatus; Soxhlet’s extraction apparatus;
     Compact extraction apparatus; Recovery of solvents;
     Authorities cited in Part First.

                    PART SECOND.
                SUGARS AND STARCHES.

     _Introduction_, pp. 58-62.—Carbohydrates;
     Nomenclature; Preparation of pure sugar;
     Classification of methods of analysis.

     _Analysis by Density of Solution_, pp.
     63-72.—Principles of the method; Pyknometers;
     Calculating volume of pyknometers; Hydrostatic
     balance; Areometric method; Correction for
     temperature; Brix hydrometer; Comparison of brix and
     baumé degrees; Errors due to impurities.

     _Estimation of Sugars with Polarized Light_,
     pp.