This important book deals with the question of what the mechanical treatment of solids is, and why the reactivity of solids is changed as a result of mechanical treatment (called mechanical activation). It outlines the possible human activities where these phenomena can be used (including the synthesis of new materials, processing of mineral raw materials, synthesis and modification of pharmaceuticals, preparation of catalysts, cosmetics).The book is concerned with a young but fast-developing branch of chemical science - mechanochemistry. It discusses the main ideas and features of this field and its possible applications in industry. It is intended for readers interested in the problems of modern chemistry, and for students in chemical departments of higher education establishments, as material for extracurricular reading.