INTRODUCTION INORGANIC CHEMISTRY With 82 Engravings on Woocl - 1872 - PEEFACE - THE encouraging reception which my Laboratory Text Book met with in this countiy, as well as in America, and the experience which I since have had of its working with a large class of chemical students, have induced me to render the book still more generally useful by publishing it in two parts, and by somewhat enlarging the st pai-t. I am in hope that this first volume may now take rank as a suitable text book for e1ementa. r c lasses preparing for the chemical examiuations which are held annually under the Science and Art Department. The admirable list of experiments, sketched out by Dr. Prankland, in the Syllabus issued by the Department, will be found interwoven throughout the text. This I was able to do without deviating from the original plan of the book, which consists mainly in deducing the fundamental laws of chemistry from experimental facts, and thus to lay a sound foundation for qualitative and quantitative analyses. From my own laboratory experience, I can coddently recommend this experimental method of teaching. Large classes of students can be instructed with comparative ease, and theoretical difficulties, which are usually overcome only by a long course of chemical study, may be grappled with at t. he earliest stages even. I have found the theory of atomicity of chemical elements remarkably conducive to a quick and thorough understanding of chemical-changes. Graphic illustrai-ions, I need scarcely remark, may be discarded as soon as they have fulflled their purpose, and as soon as the pupils have become familiar with the use of the constitutional tjymbolic formula employed in this work. The Questions and Exercises, placed at the end of most of the chapters, constitute an essential feature of the book. They will be found of great use if the written answers are examined by the teasher, a any shortcomings discussed with the pupils. This entails no doubt, much labour, but it forms, in my experience, the only eafe means of controlling and rendering the laboratory teaching thoroughly efficient. Most of the experiments can be read performed by beginners, if the directions given in the text are attended to, others again, are perhaps more suited to tblecture-room. The selection may, however, be safely left to each teacher. When the chemical instruction in schools or elementary science classes has, of necessity, to be conducted by lectures only, this little book will, when placed in the hands of the pupils, also form a useful companion and guide for private study. The h a i chapter contains a brief summary of all the previous experimental facts, classified under four chemical changes, a summary which, I trust, will reconimelld itself to the practical teacher. In conclusion, I have to thank Mr. A. J. Greenaway, Junior Assistant in the Laboratory, for his kind help in preparing a number of new wood-cuts. SOUTH KENSIRWON, Oct. 18, 1872. TABLE OF CONTENTS. CHAPTER I. PAGE Hydrogen. Properties of Hydrogen. Compound of Hydrogen with Oxygen. Water . . . . . . .. .. . . . . . . . l Oxygen. Properties of oxygen. Nitrogen. Composition of air. Compounds of oxygen with metals, Oxides. Compounds of oxygen with sulphur and phosphorus. Combustion of carbon in oxygen. Volume combination of hydrogen and oxygen . . . . . . . . . . 6 Physical states of matter-solids, liquids, and gases. 3Iechanical mixture. Chemical combination. Chemical reactions combinations and decom- positions B i n 9 compounds. Names and symbols of elements . . 19 Reductions. Chemical affiity. Indirect oxidation...