Arsenic

Metallic shiny semi-metal that forms extremely toxins compounds with hydrogen and other substances. Arsen is highly carcinogenic, yet arsenic compounds are used as components of certain medicines. Already in ancient Antiquity, various arsenic compounds were used in viticulture against insects in the Roman Empire, as reported by the Roman scholar Pliny (23-79). Thus, it is one of the oldest insecticides. Albertus Magnus (1200-1280) first described the production of arsenic around 1250 by reducing arsenic with coal. He is therefore considered the discoverer of the element.

The image on the right shows native arsenic in low-grape formation from Sankt Andreasberg in the Harz (in the south of Lower Saxony). In modern times, sodium salts of arsenic trioxide (also arsenic) were previously used worldwide against plant pests, as fungicides (anti-fungal agents) in the timber industry, as wood preservatives, as rat poison, and as decolorizing agents in glass manufacturing. In viticulture, arsenic-containing agents are now banned, in Germany since 1974. In southern France, there are still former vineyard areas that have been banned from any cultivation to this day due to excessive arsenic residues in the soil. See also under plant protection and pesticides.