Gray (unit) Gray (unit) The gray (symbol: Gy) is a derived unit of ionizing radiation dose in the International System of Units (SI). It is defined as the absorption of one joule of radiation energy per kilogram of matter. It is used as a unit of the radiation quantity absorbed dose which measures the energy deposited in a unit mass at a certain position, and of the radiation quantity kerma, which is the amount of energy that is transferred from photons to electrons per unit mass at a certain position. The corresponding cgs unit to the gray is the rad (equivalent to
Insanity in Ancient and Modern Life which his work was received. His books, including the Insanity in Ancient and Modern life, are often cited and referred to in scientific literature about sociocultural causes and influential factors contributing to insanity in the past and present. Additionally, he is often minorly mentioned in historical books about the emergence of psychology as a discipline. Tuke was among the first persons to recognize an increase in the prevalence of insanity by making use of statistics to identify possible causes, which he clarifies in great detail in "Insanity in Ancient and Modern Life." As many of his other books, the book