This is a textbook on medical roentgenology written for the general practitioner and the medical student. It contains a discussion of the physics of the roentgen rays, the principles underlying the roentgen technic and roentgenologic investigations. There are chapters on the general and the local roentgenologic diagnosis as related to pathologic anatomy, physiology and clinical knowledge. The text further contains a discussion of the biologic properties of roentgen rays and of the principles of general and local roentgenotherapy. The text does not attempt to be anything more than a guide for the medical student and for the general practitioner and, at best, an introduction to the study of roentgenology for the future specialist in this field. As such it is quite satisfactory and fills a gap in the armamentarium of the Russian physician.