abortifacient. Serenus Sammonicus wrote of a concoction which consisted of rue, egg, and dill. Soranus, Dioscorides, Oribasius also detailed this application of the plant. Modern scientific studies have confirmed that rue indeed contains three abortive compounds. Birthwort, a herb used to ease childbirth, was also used to induce abortion. Galen included it in a potion formula in de Antidotis, while Dioscorides said it could be administered by mouth, or in the form of a vaginal pessary also containing pepper and myrrh. The Greek playwright Aristophanes noted the abortifacient property of pennyroyal in 421 BCE, through a humorous reference in his comedy, Peace. Hippocrates (c. 460 – c. 370 BCE), the Greek physician, would advise a prostitute who became pregnant to jump up and down, touching her buttocks with her heels at each leap, so as to induce miscarriage. Other writings attributed to him describe instruments fashioned to dilate the cervix and curette inside of the uterus. Soranus, a 2nd-century Greek physician, prescribed diuretics, emmenagogues, enemas, fasting, and bloodletting as safe abortion methods, although he advised against the use of sharp instruments to induce miscarriage, due to the risk of organ perforation. He also advised women wishing to abort their pregnancies to engage in energetic walking, carrying heavy objects, riding animals, and jumping so that the woman's heels were to touch her buttocks with each jump, which he described as the "Lacedaemonian Leap". He also offered a number of recipes for herbal baths, rubs, and pessaries. In De Materia Medica Libri Quinque, the Greek pharmacologist Dioscorides listed the ingredients of a draught called "abortion wine"– hellebore, squirting cucumber, and scammony– but failed to provide the precise manner in which it was to be prepared. Hellebore, in particular, is known to be abortifacient. Tertullian, a 2nd- and 3rd-century Christian theologian, described surgical implements which were used in a procedure similar to the modern dilation and evacuation. One tool had a "nicely adjusted flexible frame" used for dilation, an "annular blade" used to curette, and a "blunted or covered hook" used for extraction. The other was a "copper needle or spike". He attributed ownership of such items to Hippocrates, Asclepiades, Erasistratus, Herophilus, and Soranus. Aulus Cornelius Celsus, a 1st-century Roman encyclopedist, offered an extremely detailed account of a procedure to extract an already-dead fetus in his only surviving work, De Medicina. In Book 9 of Refutation of all Heresies, Hippolytus of Rome, another