Familiar Letters on Chemistry | Page 4

Commerce. Some of
them treat of subjects which have already been, or will hereafter be,
more fully discussed in my larger works. They were intended to be
mere sketches, and were written for the especial purpose of exciting the
attention of governments, and an enlightened public, to the necessity of
establishing Schools of Chemistry, and of promoting, by every means,
the study of a science so intimately connected with the arts, pursuits,
and social well-being of modern civilised nations.
For my own part I do not scruple to avow the conviction, that ere long,

a knowledge of the principal truths of Chemistry will be expected in
every educated man, and that it will be as necessary to the Statesman,
the Political Economist, and the Practical Agriculturist, as it is already
indispensable to the Physician, and the Manufacturer.
In Germany, such of these Letters as have been already published, have
not failed to produce some of the results anticipated. New
professorships have been established in the Universities of Goettingen
and Wuertzburg, for the express purpose of facilitating the application
of chemical truths to the practical arts of life, and of following up the
new line of investigation and research--the bearing of Chemistry upon
Physiology, Medicine, and Agriculture,--which may be said to be only
just begun.
My friend, Dr. Ernest Dieffenbach, one of my first pupils, who is well
acquainted with all the branches of Chemistry, Physics, Natural History,
and Medicine, suggested to me that a collection of these Letters would
be acceptable to the English public, which has so favourably received
my former works.
I readily acquiesced in the publication of an English edition, and
undertook to write a few additional Letters, which should embrace
some conclusions I have arrived at, in my recent investigations, in
connection with the application of chemical science to the physiology
of plants and agriculture.
My esteemed friend, Dr. Gardner, has had the kindness to revise the
manuscript and the proof sheets for publication, for which I cannot
refrain expressing my best thanks.
It only remains for me to add a hope, that this little offering may serve
to make new friends to our beautiful and useful science, and be a
remembrancer to those old friends who have, for many years past,
taken a lively interest in all my labours.
JUSTUS LIEBIG
Giessen, Aug. 1843.

CONTENTS

LETTER I
The Subject proposed. Materials employed for Chemical Apparatus:--
GLASS--CAOUTCHOUC--CORK--PLATINUM. THE BALANCE.
The "Elements" of the Ancients, represent the forms of matter.
Lavoisier and his successors. Study of the materials composing the
Earth. Synthetic production of Minerals--LAPIS LAZULI. Organic
Chemistry.
LETTER II
Changes of Form which every kind of Matter undergoes. Conversion of
Gases into Liquids and Solids. Carbonic Acid--its curious properties in
a solid state. Condensation of Gases by porous bodies. By Spongy
Platinum. Importance of this property in Nature.
LETTER III
The Manufacture of Soda from Culinary Salt; its importance in the Arts
and in Commerce. Glass--Soap--Sulphuric Acid. Silver Refining.
Bleaching. TRADE IN SULPHUR.
LETTER IV
Connection of Theory with Practice. Employment of MAGNETISM as
a moving power--its impracticability. Relation of Coals and Zinc as
economic sources of Force. Manufacture of Beet-root Sugar--its
impolicy. Gas for illumination.
LETTER V
ISOMERISM, or identity of composition in bodies with different
chemical and physical properties. CRYSTALLISATION.
AMORPHISM. ISOMORPHISM, or similarity of properties in bodies

totally different in composition.
LETTER VI
ALLIANCE OF CHEMISTRY WITH PHYSIOLOGY. Division of
Food into nourishment, and materials for combustion. Effects of
Atmospheric Oxygen. Balance of CARBON and OXYGEN.
LETTER VII
ANIMAL HEAT, its laws and influence on the Animal Functions. Loss
and SUPPLY. Influence of Climate. Fuel of Animal Heat. Agency of
Oxygen in Disease. Respiration.
LETTER VIII
ALIMENTS. Constituents of the Blood. Fibrine, Albumen. Inorganic
Substances. Isomerism of Fibrine, Albumen, and elements of nutrition.
Relation of animal and vegetable organisms.
LETTER IX
Growth of Animals. Uses of Butter and Milk. Metamorphoses of
Tissues. Food of Carnivora, and of the Horse.
LETTER X
Application of the preceding facts to Man. Division of human Food.
Uses of Gelatine.
LETTER XI
CIRCULATION OF MATTER IN THE ANIMAL AND
VEGETABLE KINGDOMS. The Ocean. AGRICULTURE.
RESTITUTION OF AN EQUILIBRIUM IN THE SOIL. Causes of the
exhaustion of Land. Virginia. England. Relief gained by importation of
bones. Empirical farming unsatisfactory. Necessity for scientific
principles. Influence of the atmosphere. Of Saline and Earthy matters
of the soil.

LETTER XII
SCIENCE AND ART OF AGRICULTURE. NECESSITY OF
CHEMISTRY. Rationale of agricultural processes. Washing for gold.
LETTER XIII
ILLUSTRATION OF THE NECESSITY OF CHEMISTRY TO
ADVANCE AND PERFECT AGRICULTURE. Manner in which
FALLOW ameliorates the soil. Uses of Lime. Effects of Burning. Of
Marl.
LETTER XIV
NATURE AND EFFECTS OF MANURES. Animal bodies subject to
constant waste. Parts separating--exuviae--waste vegetable
matters--together contain all the elements of the soil and of food.
Various value of excrements of