"Citric acid is said to have spermicidal properties, and women used to soak sponges in lemon juice before inserting them vaginally. Mentioned in the Talmud, this was a preferred method of birth control in ancient Jewish communities. The sponge itself would act as a pessary a physical barrier between the sperm and the cervix. The great womanizer Casanova was said to have inserted the rind of half a lemon into his lovers as a primitive cervical cap or diaphragm, the residual lemon juice serving to annihilate the sperm. Lemon- and lime-juice douches following coitus were also recommended as a form of birth control, but this method was likely less effective, since sperm can enter the cervix and hence out of reach of any douching within minutes of ejaculation. Incidentally, some alternative medicine practitioners today suggest that megadoses of vitamin C (6 to 10 g a day) could induce an abortion in women under 4 weeks of pregnancy, but there’s no evidence that citrus fruits were used in this way in ancient times"