husbandry.
Indeed, without the aid of artificial manures, arable farming, as at
present carried out, would be impossible. Fifty years ago the practice
may be said to have been unknown; yet so widespread has it now become,
that at the present time the capital invested in the manure trade in
this country alone amounts to millions sterling. It need scarcely be
pointed out, therefore, that a practice in which such vast monetary
interests are involved is worthy of the most careful consideration by
all students of agricultural science, as well as, it may be added, by
political economists.

The aim of the present work is to supply in a concise and popular form
the chief results of recent agricultural research on the question of
soil fertility, and the nature and action of various manures. It makes
no pretence to be an exhaustive treatise on the subject, and only
contains those facts which seem to the author to have an important
bearing on agricultural practice. In the treatment of its subject it may
be said to stand midway between Professor Storer's recently published
elaborate and excellent treatise on 'Agriculture in some of its
Relations to Chemistry'--a work which is to be warmly recommended to all
students of agricultural science, and to which the author would take
this opportunity of acknowledging his indebtedness--and Dr J. M. H.
Munro's admirable little work on 'Soils and Manures.'

In order to render the work as intelligible to the ordinary agricultural
reader as possible, all tabular matter and matter of a more or less
technical nature have been relegated to the Appendices attached to each
chapter.

The author's somewhat wide experience as a University Extension
Lecturer, and as a Lecturer in connection with County Council schemes of
agricultural education, during the last few years, induces him to
believe that the work may be of especial value to those engaged in
teaching agricultural science.

He has to express the deep obligation he is under, in common with all
writers on Agricultural Chemistry, to the classic researches of Sir John
Bennet Lawes, Bart., and Sir J. Henry Gilbert, now in progress for more
than fifty years at Sir John Lawes' Experiment Station at Rothamsted.
His debt of gratitude to these distinguished investigators has been
still further increased by their kindness in permitting him to dedicate
the work to them, and for having been good enough to read portions of
the work in proof. In addition