Lancisi suggested that since malaria disappears after drainage it was due to some sort of poison emanating from marshes and possibly transmitted by mosquitoes. He planned a drainage scheme for marshy regions. His work included an early effort at medical cartography-- a map of the area between the gulfs of Astura and Terracina, south-southeast from Rome which identified twenty-six forested quarters ("quarti delle selve") and four ruined lands ("terre dirute").  The map also included directions of the major winds. Digital facsimile from the Internet Archive at this link.