Fresh tadpoles coming out in the spring should be washed clean in cold well-water, and swallowed whole three or four days after menstruation. If a woman swallows fourteen live tadpoles on the first day and ten more on the following day, she will not conceive for five years. If contraception in still required after that, she can repeat the formula twice and be for ever sterile... This formula is good in that it is effective, safe and not expensive. The defect is that it can be used only in the spring.