In 1891 another unusual experiment, this time in France by university professor Charles-Édouard Brown-Séquard, finally began to get to the root of the mystery. He suspected that male testes might contain some unknown substance that influenced masculinity. He proved his hypothesis the hard and fast way, by repeatedly injecting himself with a concoction made out of the blood, semen, and juices from the crushed testicles of guinea pigs and dogs. He claimed (although his findings were never replicated) that this cocktail increased his strength, stamina, and mental clarity.
