内容简介：
MANUAL OF THE CHEMICAL ANALYSIS OF ROCKS BY HENRY S. WASHINGTON, PREFACE TO THE THIRD EDITION THE present edition has been thoroughly revised and consid- erably enlarged. Some changes in details of procedure have been introduced that were suggested by the equipment and facilities of a modern laboratory, as contrasted with those which served for the work upon which the previous editions were based. But the endeavor has been made to describe the various procedures so that theymay be readily carried out by oneworking in a laboratory that is not provided with all possible facilities. Somenew methods have been introduced, but it has been thought to be the wiser course to adhere to well-known and oft-tried reliable methods, rather than to supplant them by others more recently proposed, unless these have been tried and proved to be of undoubted supe- riority. The various methods have been treated in much greater detail than in previous editions, and more stress has been laid on the sources of error both in operations and in methods experience has shown that such discussions will be of service to the intelligent student, particularly if he is working alone. It is - to be hoped that the many sources of error, and the many pre- cautions, which have been enumerated, will not induce discouragement at the outset, but that they will, rather, serve to stimulate to greater and more active and intelligent interest in and understanding of the analysis of rocks. Some of the most recent and standard text-books have been at my elbow during the revision. The work throughout is greatly indebted, as before, to the invaluable writings, as well as to the friendly advice, of Dr. W. F. Hillebrand while thetreatise of Dr. J. W. Mellor has also been of great assistance and has been constantly consulted. It is a pleasure to express my obligations Director of the Geophysical Laboratory, for his permission to undertake this revision while a member of its staff and I would also tender my thanks to Dr. E. G. Zies, of this laboratory, for much friendlyand valuable criticism and counsel, as well as for his kindness in reading the proofs during my absence. H. S. W. GEOPHYSICAL LABORATORY, Carnegie Institution of Washington, June 30, 1918. PREFACE TO THE FIRST EDITION THE object of this book is to present to chemists, petrologists, mining engineers and others who have not made a particular study of quantitative analysis, a selection of methods for the chemical analysis of silicate rocks, and especially those of igneous origin. While the publication of such a work may seem superfluous in view of the existence of Hillebrands treatise on this special topic, yet justification may be found in the fact that the latter is intended, not so much for one who is not very conversant with the subject, as for the practiced analyst, to whom it is an indispensable guide. A further reason for its appearance is that, apart from Hille- brands book and a paper by Dittrich, there does not seem to exist any separate modern treatise on the chemical analysis of rocks. The space devoted to this branch of analysis in the text- books is usually very small, and the various methods are widely scattered and often inadequately described. This is especially true in regard to the minutiae of manipulation and precautions to be observed, and to the determination of elements which, though usually accounted rare, have of late yearsbeen shown to be very common rock constituents. This neglect is rather striking in view of the prominence given in the last decade or so to the chemical composition of igneous rocks...