ABSTRACT

Arsenic, described by Albertus Magnus in about 1250, has played an important role in the cultural history of mankind. Pure metallic arsenic is not poisonous, but it oxidizes in moist air to form arsenic trioxide, a toxic compound. Because of its properties as a scentless and tasteless powder, arsenic trioxide became a murderous weapon, “king of poisons” (1). Testing of a potential essentiality of As was successful only in the 1970s. Deficiency symptoms were observed in rats, goats, mini-pigs, and chicks (2).