Cowpox children. In 1796, British medical practitioner Edward Jenner tested the theory that cowpox could protect someone from being infected by smallpox. Although cowpox originates on the udder of cows, Jenner took his sample from a milkmaid, Sarah Nelmes. Jenner extracted the pus of one of the lesions formed by cowpox on Nelmes to another individual who never had smallpox, James Phipps. He eventually developed a scab and fever that was manageable. Approximately six weeks later, Jenner then introduced an active sample of the smallpox virus into Phipps to test the theory. After being observed for an extended amount of time,
Jenner (crater) basaltic lava, leaving a dark, level interior. There are no breaks in the exterior rim where the lava could have entered the crater, so it was presumably flooded from below. The floor is marked only by a few tiny craterlets. Surrounding Jenner is a rampart of ejecta that extends for over a half crater diameter in some directions. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Jenner. Jenner (crater) Jenner is a lunar crater that is located within the Mare Australe. It lies just