**Summary:** This is a detailed textbook on crystal physics, authored by Woldemar Voigt, originally published in 1910 and reprinted in 1966. The book focuses on the physical properties of crystals, excluding crystal optics. It includes 213 figures and one table, and is part of the BIBLIOTHECA MATHEMATICA TEUBNERIANA series. The text is structured into multiple chapters, covering fundamental concepts, symmetry, crystal systems, physical functions, and various physical phenomena such as elasticity, piezoelectricity, and thermal expansion. The book also discusses the theoretical foundations of crystal physics, including thermodynamics, electromagnetism, and the behavior of crystals under different conditions. It provides a comprehensive overview of the subject, with an emphasis on the mathematical and physical principles underlying crystal behavior. The text is written in a clear and systematic manner, making it a valuable resource for students and researchers in the field of crystal physics. The book also includes a foreword by Professor M. von Laue, highlighting its significance in the field of crystal research. The content is further expanded with additional material, including a 1915 paper by Voigt, which is appended to the original edition. The book is notable for its detailed treatment of crystal symmetry, the application of tensor analysis, and the integration of physical and mathematical concepts. It serves as a foundational text for understanding the physical properties of crystals and their behavior under various conditions.**Summary:** This is a detailed textbook on crystal physics, authored by Woldemar Voigt, originally published in 1910 and reprinted in 1966. The book focuses on the physical properties of crystals, excluding crystal optics. It includes 213 figures and one table, and is part of the BIBLIOTHECA MATHEMATICA TEUBNERIANA series. The text is structured into multiple chapters, covering fundamental concepts, symmetry, crystal systems, physical functions, and various physical phenomena such as elasticity, piezoelectricity, and thermal expansion. The book also discusses the theoretical foundations of crystal physics, including thermodynamics, electromagnetism, and the behavior of crystals under different conditions. It provides a comprehensive overview of the subject, with an emphasis on the mathematical and physical principles underlying crystal behavior. The text is written in a clear and systematic manner, making it a valuable resource for students and researchers in the field of crystal physics. The book also includes a foreword by Professor M. von Laue, highlighting its significance in the field of crystal research. The content is further expanded with additional material, including a 1915 paper by Voigt, which is appended to the original edition. The book is notable for its detailed treatment of crystal symmetry, the application of tensor analysis, and the integration of physical and mathematical concepts. It serves as a foundational text for understanding the physical properties of crystals and their behavior under various conditions.