Chemistry Core

SODIUM 513 XIII. POTASSIUM, RUBIDIUM, CÆSIUM AND LITHIUM. SPECTRUM ANALYSIS 543 XIV. THE VALENCY AND SPECIFIC HEAT OF THE METALS. MAGNESIUM, CALCIUM, STRONTIUM, BARIUM, AND BERYLLIUM 581 PRINCIPLES OF CHEMISTRY INTRODUCTION The study of natural science, whose rapid development dates from the days of Galileo ([+]1642) and Newton ([+]1727), and its closer application to the external universe[1] led to the separation of Chemistry as a particular branch of natural philosophy, not only owing to the increasing store of observations and experiments relating to the mutual transformations of substances, but also, and more especially, because in addition to gravity, cohesion, heat, light and electricity it became necessary to recognise the existence of particular internal forces in the ultimate parts of all substances, forces which make themselves manifest in the transformations of substances into one another, but remain hidden (latent) under ordinary circumstances, and whose existence cannot therefore be directly apprehended, and so for a long time remained unrecognised.

Longmans, Green, and Co 39 Paternoster Row, London New York and Bombay 1897 All rights reserved PREFACE TO THE ENGLISH TRANSLATION The first English edition of this work was published in 1891, and that a second edition is now called for is, we think, a sufficient proof that the enthusiasm of the author for his science, and the philosophical method of his teaching, have been duly appreciated by English chemists. In the scientific work to which Professor Mendeléeff's life has been devoted, his continual endeavour has been to bring the scattered facts of chemistry within the domain of law, and accordingly in his teaching he endeavours to impress upon the student the _principles_ of the science, the generalisations, so far as they have been discovered, under which the facts naturally group themselves. Of those generalisations the periodic law is perhaps the most important that has been put forward since the establishment of the atomic theory. It is therefore interesting to note that Professor Mendeléeff was led to its discovery in preparing the first Russian edition of this book. It is natural, too, that the further application and development of that generalisation should be the principal feature of this, the latest edition.

EBOOK THE PRINCIPLES OF CHEMISTRY, VOLUME I *** Note: Project Gutenberg also has an HTML version of this file which includes the original illustrations. See 51326-h.htm or 51326-h.zip: (https://www.gutenberg.org/cache/epub/51326/pg51326-images.html) or (https://www.gutenberg.org/files/51326/51326-h.zip) Images of the original pages are available through Internet Archive. See https://archive.org/details/cu31924012367441 Transcriber's note: Text enclosed by underscores is in italics (_italics_). A carat character is used to denote superscription. A single character following the carat is superscripted (example: 0·01717_t_^2). Multiple superscripted characters are enclosed by curly brackets (example: V_{_0_}(1-K_t_)^{-1}). The ligature oe has been transcribed as [oe]. The dagger sign has been transcribed as [+]. The infinity sign has been transcribed as [oo]. THE PRINCIPLES OF CHEMISTRY by D. MENDELÉEFF Translated from the Russian (Sixth Edition) by George Kamensky, A.R.S.M. of the Imperial Mint, St Petersburg: Member of the Russian Physico-Chemical Society Edited by T. A. Lawson, B.Sc. PH.D. Examiner in Coal-Tar Products to the City and Guilds of London Institute Fellow of the Institute of Chemistry In Two Volumes VOLUME I.

The time has arrived when a knowledge of physics and chemistry forms as important a part of education as that of the classics did two centuries ago. In those days the nations which excelled in classical learning stood foremost, just as now the most advanced are those which are superior in the knowledge of the natural sciences, for they form the strength and characteristic of our times. In following the above and chief aim, I set myself a second object: to furnish a text-book for an elementary knowledge of chemistry and so satisfy a want which undoubtedly exists among students and those who have recourse to chemistry either as a source of truth or welfare.[2] Hence, although the fundamental object of this work was to express and embrace the general chemical teaching of the present day from a personal point of view, I have nevertheless striven throughout to maintain such a level as would render the 'Principles of Chemistry' accessible to the beginner. Many aspects of this work are determined by this combination of requirements which frequently differ widely. An issue was only possible under one condition, _i.e._ not to be carried away by what appears to be a plausible theory in explaining individual facts and to always endeavour to transmit the simple truth of a given fact, extracting it from the vast store of the literature of the subject and from tried personal experience.

The, to me, unexpectedly rapid success with which the teaching of the periodicity of the elements has spread in our science, and perhaps also, the perseverance with which I collected in this work, and upon a new plan, the most important data respecting the elements and their mutual relations, explained sufficiently the fact that the former (5th, 1889) edition of my work has been translated into English[4] and German[5] and is being translated into French.[6] Deeply touched by the favourable opinions expressed by English men of science upon my book, I ascribe them chiefly to the periodic law placed at the basis of my treatise and especially of the second part of the book, which contains a large amount of data having a special and sometimes quite unexpected, bearing from the point of view of this law. As the entire scheme of this work is subordinated to the law of periodicity, which may be illustrated in a tabular form by placing the elements in series, groups, and periods, two such tables are given at the end of this preface. [2] I recommend those who are commencing the study of chemistry with my book _to first read only what is printed in the large type_, because in that part I have endeavoured to concentrate all the fundamental, indispensable knowledge required for that study.