Mercury was not discovered in the sense of being found for the first time. It has been known since ancient times.

While the exact discoverer is unknown, it's believed that ancient Egyptians, Greeks, and Chinese were aware of mercury and used it in various ways.

Here's why:

* Ancient Egyptians: Used mercury in cosmetics and for embalming.

* Ancient Greeks: Referred to it as "hydrargyrum" (meaning "liquid silver") and used it in medicine and alchemy.

* Ancient Chinese: Used mercury in medicine and in the process of extracting gold.

So, rather than a single scientist, mercury's discovery is attributed to the collective knowledge of ancient civilizations.