"The Principles of Chemistry, Volume II" is a well-known scientific work of Dmitri Ivanovich Mendeleev, an outstanding Russian scientist and chemist. In the second volume of this book, the author examines the fundamental principles of chemistry, in particular, develops the theory of chemical elements and their relationships. Mendeleev first systematized a large amount of chemical knowledge and created the periodic table of chemical elements, which became the foundation for further research in the field of chemistry. This book is an important source of knowledge for anyone interested in chemistry and wishing to better understand the basic patterns in chemical processes.