It's tricky to pinpoint one person who "discovered" gas, as the understanding of gases evolved over centuries. Here's a breakdown:

* Early Observations: People were aware of gases like air and smoke since ancient times.

* Theophrastus (372-287 BC): He described "air" as a fundamental element, and noted that some materials release vapors when burned.

* Jan Baptista van Helmont (1579-1644): This Flemish chemist was the first to systematically study gases. He identified "gas sylvestre" (carbon dioxide) from burning charcoal and "gas pingue" (methane) from fermenting dung. He also gave gases their name, deriving it from the Greek word "chaos."

* Robert Boyle (1627-1691): Boyle conducted experiments on air and pressure, leading to Boyle's Law (the relationship between pressure and volume of a gas).

* Joseph Black (1728-1799): Black discovered carbon dioxide, which he called "fixed air," through his work on the properties of limestone.

* Henry Cavendish (1731-1810): He isolated and characterized hydrogen, which he called "inflammable air."

* Carl Wilhelm Scheele (1742-1786): Scheele discovered oxygen, which he called "fire air," although he did not fully understand its properties.

* Joseph Priestley (1733-1804): Independently of Scheele, Priestley also discovered oxygen and studied its properties.

Therefore, attributing the discovery of "gas" to one person is not accurate. Many scientists contributed to the understanding and characterization of different gases over time.