Marcus Terentius Varro and The Invisible Creatures That Cause Disease

In the first century BC, nearly two thousand years before the invention of the microscope, the Roman scholar Marcus Terentius Varro made a remarkable observation about the cause of disease. Writing in his agricultural treatise De Re Rustica around 37 BC, Varro advised landowners to avoid building homes near swamps. His reason was unusual for the time: There are bred certain minute creatures which…