Ancient Egyptian pregnancy test survived millenia because it worked (2018)
Kind of a tangent (but potentially useful and little known) is the "baker's method" of male contraception.https://en.wikipedia.org/wiki/Marthe_Voegelihttps://en.wikipedia.org/wiki/Heat-based_contraception> It has long been observed that men who work in professions that expose them to heat in the nether regions: bakers, cooks, steamworkers; have had a hard time fathering children. Interestingly, men in these professions were observed to start having children after retiring or finding a new job. Based on these observations, Dr. Martha Vogeli [sic, her name ends with 'e': Marthe] ran a long set of experiments starting in the 1940’s in India. After trying all possible combinations, Dr. Vogeli found a consistent method for inducing temporary infertility in men by a series of hot baths. In short, men who sat in hot water for 45 minutes a day for 3 weeks were protected for at least 6 months.~ https://www.dontcookyourballs.com/heat-based-contraception-n...