धुआँ (en. Miasma)

That said, although Galileo was smart enough to avoid looking directly at the sun, we do know of at least one other great mind from history who wasn’t and temporarily went blind as a result of looking directly into our neighborhood miasma of incandescent plasma.

In this way he refuted Galen's miasma theory (poison gas in sick people).

But smell had a much more complex place in miasma theory - the idea that diseases were caused by poisonous airs - than has often been assumed.

He observed queens laying eggs in open cells, but still had no idea of how a queen was fertilized; nobody had ever witnessed the mating of a queen and drone and many theories held that queens were "self-fertile" while others believed that a vapor or "miasma" emanating from the drones fertilized queens without direct physical contact.

In 1854, right in the middle of the third cholera pandemic, a physician named John Snow nay-sayed all those miasma truthers and proposed a link between cholera and contaminated drinking water, developing a theory that cholera wasn’t spreading through polluted air, but through waterways.