Chemistry, inorganic and organic, with experiments

Preface To The Fiest Edition

This work is designed to give a clear and simple description of the elements and their principal compounds, and of the chemical principles involved in some of the most important branches of manufacture. Keeping this in view, I have employed as few technical terms as possible, especially at the commencement, so that the student may glide into Chemistry without having first to toil through a difficult chapter on the terminology of the science, which he can never appreciate until he has become acquainted with the examples which serve to illustrate its application.

Convinced, by experience, of the great assistance afforded to the learner by referring him to a simple illustrative experiment, I have introduced, generally in smaller type, a description, and in most cases a wood-engraving, of the experiments which I have found most useful in illustrating lectures, hoping that these may prove of service in fixing the attention of the student, and may assist those who are desirous of performing such experiments for their own instruction, or for that of a class.

In general, English weights and measures, and Fahrenheit thermometric degrees, have been employed, as conveying more clearly to the beginner the absolute values expressed, since the mental effort of converting what must still be called the Continental systems, slight though it be, might have the effect of diverting the attention of the reader from the chemical question under consideration. The various calculations have been conducted in the simplest arithmetical form, because the more compendious

VI PREFACE.

algebraical expressions are not so generally intelligible, and when the principle is once understood, a general algebraical formula for the calculation is easily constructed by the learner.

The special attention devoted to Metallurgy and some other branches of Applied Chemistry, will render the work useful to those who are being educated for employment in manufacture.

The military student will find more than the usual space allotted to the chemistry of the various substances employed in warlike stores.

C. L. B.

Preface To The Second Edition

During the five years which have elapsed since the publication of the First Edition of this work, the adoption of the atomic system of notation has become so general among English chemists that I have felt obliged to employ it in the present edition. This change has rendered it necessary to commence the study of the non-metallic elements with Hydrogen instead of Oxygen, a course attended with some disadvantage to beginners, because Hydrogen is prepared and studied by processes which are strictly technical, whereas Oxygen is known in a free state in the atmosphere, where we constantly witness its chemical action upon other bodies. Moreover, the circumstance that the science of chemistry originated in the careful study of the phenomena of combustion towards the end of the last century, appears to me greatly in favour of our commencing a course of elementary chemistry from that point. Since, however, Hydrogen is the chemical unit of the atomic system, whilst Oxygen is a diatomic element, I have found it absolutely necessary to assign to this latter the second place. Indeed, to teach the atomic system in its integrity, it would be necessary to postpone the study of Oxygen until all the monatomic elements had been disposed of, and thus to defer, till a late period, the consideration of the processes of combustion which awaken the interest of even the least observant student.

Although I thoroughly appreciate the beauty and harmony of the atomic system, and acknowledge the immense assistance which it has afforded in research, I contemplate with regret its almost

Vlll PREFACE.

universal adoption by chemical teachers in this country, since it involves the necessity of propounding the difficult hypothesis of the finite divisibility of matter at the commencement of a study which has been recommended to the student as strictly experimental, and as affording a mental relief from the abstractions of mathematics. Even if it be alleged that it is not necessary to mention atoms to beginners, but that the teacher .may confine himself, as is now sometimes the case, to combining proportions, the combining weight of hydrogen in water must be represented as 2 ; a perplexing, and at this stage totally unnecessary inquiry being suggested to the mind of the pupil, why it is set down as 1 in the lists of combining weights.

The numerous failures in Chemistry at the examinations now so much in vogue, appear to indicate the difficulty experienced by the immature minds of the young in laying hold of the ideas of atomicity and quantivalence which pervade many of the questions, whereas the mutual relations between the elements and their compounds, which are easily impressed on the mind by experiment, and involve as much Chemistry as the young student can grasp, are treated as of subordinate importance.

The tendency to regard Chemistry as a modified Algebra has become so great since the general introduction of the atomic system, that it is not uncommon for teachers in schools to prepare the pupils for examination in Chemistry, who have themselves never had the opportunity of learning how to conduct the simplest chemical operation.

To acquire a knowledge of the rudiments of Chemistry by personal observation, has, without doubt, a very beneficial effect ; but to get tip a number of formulas and equations, with the sole object of gaining a certain number of marks at examination, altogether defeats the object with which Chemistry should be introduced into a system of liberal education.

In this edition I have endeavoured to preserve, as far as possible, the simple and experimental character of the work, and at the same time to employ formulae in harmony with those now generally used. The nomenclature has undergone very little change, since there is by no means a general agreement upon this subject ; and I deem it of the greatest importance that tie names by which

PREFACE. IX

chemical compounds are known in common life should be kept before the student in a chemical treatise.

The attention of the student is called to the Table of Contents, which has been drawn up to serve the purpose of an abstract, by which he may examine himself upon each paragraph of the book. The Index is also a dictionary of the most important formulas, in which either the name of a compound may be referred to, in order to find its formula, or the formula may be sought when it is desired to ascertain the compound to which it belongs.

C. L. B.

King's College, London, July 1872.

*j* In the following pages, the smaller type contains not only the descriptions of experiments, but all such matter as would be of less importance to a student desiring only a general knowledge of the subject without going into details.'

A Table of Atomic Weights w T ill be found at page 628.

Table Of Contents

Introduction. — Definitions, . . . . . 1

Enumeration and classification of elements, with their symbols, . 2

Classification of compounds into organic and inorganic, . . 3