Purists only gathered dew on the first while others believed the power persisted for the whole month
Folklore maintains that dew gathered in May is special. For one thing, it is supposed to give you a flawless complexion. In 1667, Samuel Pepys’ wife went to Woolwich to collect May dew, “the only thing in the world to wash her face with”.
While purists only gathered dew on 1 May, others believed the power persisted for the whole month. The Royal Society took May dew seriously, the mathematician John Pell telling a meeting about a man whose warts it had cured. The chemist Robert Boyle mentioned a recipe for making vinegar from May dew, and copious quantities were harvested for experimentation.