ELEMENTS

OF

AGRICULTURAL CHEMISTRY

BY

THOMAS ANDERSON, M.D.

F.R.S.E., F.C.S.

PROFESSOR OF CHEMISTRY IN THE UNIVERSITY OF GLASGOW, AND CHEMIST TO THE HIGHLAND AND AGRICULTURAL SOCIETY OF SCOTLAND.

EDINBURGH:

ADAM AND CHARLES BLACK.

1860.

ERRATUM.

Page 190, line 11, for "gallon" read "ton."

PRINTED BY R. AND R. CLARK, EDINBURGH.

Transcriber's note: Many of the tables needed to be split to fit space constraints.

PREFACE.

The object of the present work is to offer to the farmer a concise outline of the general principles of Agricultural Chemistry. It has no pretensions to be considered a complete treatise on the subject. On the contrary, its aim is strictly elementary, and with this view I have endeavoured, as far as possible, to avoid unnecessary technicalities so as to make it intelligible to those who are unacquainted with the details of chemical science, although I have not hesitated to discuss such points as appeared essential to the proper understanding of any particular subject.

The rapid progress of agricultural chemistry, and the numerous researches prosecuted under the auspices of agricultural societies and private experimenters in this and other countries, render it by no means an easy task to make a proper selection from the mass of facts which is being daily accumulated. In doing this, however, I have been guided by a pretty intimate knowledge of the wants of the farmer, which has induced me to enlarge on those departments of the subject which bear more immediately on the every-day practice of agriculture; and for this reason the composition and properties of soils, the nature of manures, and the principles by which their application ought to be governed, have been somewhat minutely treated.

In all cases numerical details have been given as fully as is consistent with the limits of the work; and it may be right to state that a considerable number of the analyses contained in it have been made in my own laboratory, and that even when I have preferred to quote the results of other chemists, they have not unfrequently been confirmed by my own experiments.

University of Glasgow,
1st November 1860.

CONTENTS.

Page

Introduction 1


CHAPTER I.

The Organic Constituents of Plants.

Carbon ... Carbonic Acid ... Hydrogen ... Nitrogen ... Nitric Acid ... Ammonia ... Oxygen ... Sources whence obtained ... The Atmosphere ... The Soil ... Source of the Inorganic Constituents of Plants ... Manner in which the Constituents of Plants are absorbed 8


CHAPTER II.

The Proximate Constituents of Plants.

The Saccharine and Amylaceous Constituents ... Cellulose ... Incrusting Matter ... Starch ... Lichen Starch ... Inuline ... Gum ... Dextrine ... Sugar ... Mucilage ... Pectine and Pectic Acid ... Oily or Fatty Matters ... Margaric, Stearic, and Oleic Acids ... Wax ... Nitrogenous or Albuminous Constituents of Plants and Animals ... Albumen ... Fibrine ... Casein ... Diastase 40


CHAPTER III.

The Changes which take place in the Food of Plants during their Growth.

Changes occurring during Germination ... Changes during the After-Growth of the Plant ... Decomposition of Carbonic Acid ... Decomposition of Water ... Decomposition of Ammonia ... Decomposition of Nitric Acid 54


CHAPTER IV.

The Inorganic Constituents of Plants.

The Amount of Inorganic Matters in Different Plants ... The Relative Proportions of Ash in the Different Parts of Plants ... Influence of the Nature of the Soil on the Proportion of Mineral Matters in the Plant ... The Composition of the Ashes of Plants ... Classification of Different Plants 63


CHAPTER V.

The Soil—Its Chemical and Physical Characters.

The Origin of Soils ... Composition of Crystalline and Sedimentary Rocks ... their Disintegration ... Chemical Composition of the Soil ... Fertile and Barren Soils ... Mechanical Texture of Soils ... Absorbent Action of Soils ... their Physical Characters ... Relation to Heat and Moisture ... The Subsoil ... Classification of Soils 83


CHAPTER VI.

The Improvement of the Soil by Mechanical Processes.

Draining ... Its Advantageous Effects ... Subsoil and Deep Ploughing ... Improving the Soil by Paring and Burning ... Warping ... Mixing of Soils ... Chalking 137


CHAPTER VII.

The General Principles of Manuring.

Fundamental Principles upon which Manures are applied ... Special and General Manures ... Importance of this distinction ... Views regarding the Theory of Manures ... Remarks on Special Manures ... Action of Manures on the Chemical and Physical Properties of a Soil ... Remarks on the Application of Manures152


CHAPTER VIII.

The Composition and Properties of Farm-yard and Liquid Manures.

Farm-yard Manure ... Urine ... Composition of ... Dung ... Composition of ... Farm-yard Manure ... Composition of ... Management of Dung-Heaps ... Box-feeding ... Fermentation and application of Manure ... Liquid Manure ... Composition and application of ... Sewage Manure ... Its composition and application 166


CHAPTER IX.

The Composition and Properties of Vegetable Manures.

Rape-Dust, Mustard, Cotton and Castor Cake ... Composition of various Oil-Cakes ... Malt-Dust, Bran, Chaff, etc. ... Straw and Saw-dust ... Manuring with Fresh Vegetable Matter ... Green Manuring ...