Boron, arsenic, and antimony, among other substances, are used as dopants when added to a pure semiconductor material to alter its electrical characteristics.
Artificially produced gemstones[?] (such as Ruby (gemstone)) usually contain a dopant to identify them as such.
... (1830)
Handbuch einer allgemeinen Geschichte den Poesie (1832-33)
Die Pädagogik als System (1848)
Aesthetik des Hässlichen (1853)
Die Poesie and ihre Geschichte ...