The two natural arsenic sulphides - realgar (brownish-red) and orpiment (lemon yellow) - have been known since ancient times. The Greeks gave them the name αρσενικος, which means male. This etymology was related to the ancient concept of putting metals into the categories of male and female depending on whether they reacted easily or not with other metals. Subsequently, the word arsenic was given to the metal itself.
There are indications that arsenic was isolated in the 13th century, but Berzelius was the first to undertake systematic research on the element and its compounds in the early part of the 19th century.