jan 1, 1796 - 1796 England
Description:
Edward Jenner noticed that the milkmaids only showed symptoms of cow pox by spots on there hands. He also noticed, if they got small pox they wouldn't receive small pox. Jenner discovered that cow pox can be given as a weakened form of small pox.Added to timeline:
Date:
jan 1, 1796
Now
~ 228 years ago
