ELEMENTARY CHEMICAL MICROSCOPY by MONNIN CHAMOTOriginally published in 1915. PREFACE TO SECOND EDITION: In the six years which have elapsed since the appearance of the first edition, the great majority of American Chemists have come to regard the microscope as a necessary adjunct to the chemical laboratory. The Great War brought us face to face with a multitude of intricate industrial and economic problems, in the solution of which the chemist was not slow to appreciate the importance and the value of industrial chemical microscopy. It is probable that a greater number of new applications of microscopic methods were made in our industries during the war than in the entire preceding quarter of a century. Since, however, this progress has been rather in applying existing methods to the solution of new problems, it has been thought best to preserve in this new edition the same view-point as in the old. This book is intended to serve as an introduction to the micro scope and its accessories as tools for the chemist to work with and even though practical applications are referred to, the author has made no effort, and has no desire, to have the book take the form of a manual of industrial microscopy. The changes made have been chiefly in the rearrangement of the Chapters, in the elaboration of the data presented and in the rewriting of obscure passages. Comparatively little new apparatus has been described or new methods introduced. Illustrations of the characteristic crystals constituting a satisfactory test for the elements and compounds discussed in Chapter XIV have been omitted as in the previous edition for two reasons, i The book is essentially a text and not a reference book. It came into being because of the necessity of providing a text for use by students in Cornell University. In this course, training in accurate observation is emphasized it has been found to lead to better results if the student is obliged to dis cover for himself, under guidance, the characteristic morphology of the materials studied and having found typical crystals, fibers, etc., to sketch them in his note-book. 2 The cost of the book to the student would have been very greatly increased. This explanation is not offered as an apology for the short comings of this book, which the author appreciates are many, but is given as an expression of his opinion that better work can be obtained from students providing there is adequate assistance given in the laboratory. In order to meet the often expressed needs of advanced students and of professional chemists, a Handbook of Microscopic Qualitative Analysis is in preparation which will be copiously illustrated by photo-micro graphs and which will thus serve to supplement the present introductory text. In answer to repeated requests, a brief synopsis of the course in Introductory Chemical Microscopy as now given in the Department of Chemistry, Cornell University, has been inserted in the Appendix. The author is indebted to Professor S. H. Gage and to Mr. C. W. Mason for many helpful suggestions in the preparation of this second edition. E. M. C. ITHACA, N. Y., Jan. 25, 1921. PREFACE TO FIRST EDITION: The American chemist, usually ready to accept with alacrity all time, labor and money saving devices, has been strangely backward in taking advantage of the benefits to be gained through the intelligent application of chemical microscopic methods in the industries and in research...