Roentgen (unit) absorbed dose in a wide range of matter. When measuring absorbed dose in a human due to external exposure, the SI unit the gray, or the related non-SI rad are used. From these can be developed the dose equivalents to consider biological effects from differing radiation types and target materials. These are equivalent dose, and effective dose for which the SI unit sievert or the non-SI rem are used. The following table shows radiation quantities in SI and non-SI units: Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays
Friedrich Wilhelm Theile addition to his own writings, he translated several works by foreign physicians and scientists — Louis Delasiauve, Franciscus Cornelis Donders, Auguste Ambroise Tardieu, Pieter Harting and Jacobus Schroeder van der Kolk. Friedrich Wilhelm Theile Friedrich Wilhelm Theile (11 November 1801, in Buttstädt – 20 October 1879, in Weimar) was a German physician and anatomist. In 1825 he received his medical doctorate from the University of Jena with the dissertation-thesis "De Musculis nervisque laryngeis". From 1828, with Heinrich Wilhelm Ferdinand Wackenroder, he was in charge of the pharmaceutical institute at Jena. In 1831 he became an associate professor, and three years