This book has been written to meet the demand for a Simple and practical treatment of the principles and applications of Chemistry. The author realizes that demands are now being made of teachers of Chemistry which would hardly have been considered several years ago. Not only must the student be taught the principles of chemistry and their applications in daily life, but he must be taught in such a way that, Should occasion arise, he can use chemistry in earning a living. The plea SO long made that chemistry is practical and useful is now being tested. Consequently the author has kept one thought in mind during the preparation of this book, viz.: principles and applications must go hand in hand. Principles are the foundation upon which applications rest. To teach either one exclusively is hazardous, for when separated one is as barren as the other is superficial. The author has aimed to include in this book not only the principles of Chemistry universally regarded as an essential part of a well-rounded course, but also numerous practical applications. First, the text includes a clear, Simple treatment of the facts, laws, theories, and principles that serve as the foundation of chemistry. This material is written in a style which assumes that the book is to be read, studied, and used by beginners. Special efiort has been made to present very clearly such needful topics as atomic weights, equations, and valence. All of this material is made more serviceable by a liberal selection of original exercises and problems containing many novel and attractive features. Teachers will find in these exercises and problems abundant material to drive home principles and arouse interest in the vocational aspects of chemistry.