Doctor Phosphorus (Alexander James Sartorius) is a fictional supervillain who has appeared in various comic book series published by DC Comics. Primarily an enemy of Batman, the villain exists in DC's main shared universe, known as the DC Universe. Publication history Doctor Phosphorus first appeared in Detective Comics #469 and was created by Steve Englehart. Fictional character biography Dr. Alex Sartorius, alias Doctor Phosphorus was a member of the Tobacconists' Club, who wanted to build a nuclear power plant in Gotham City with help from the Club's chairman, Rupert Thorne. However, the people of Gotham refused the construction of the plant and he was forced to take the project far from the city. Eventually, Sartorius was transformed by sand irradiated during the nuclear plant's meltdown, driven up one element on the chemical table, from silicon to phosphorus. His body was changed as his skin would burn at any contact and his skeleton showed through his flesh similar to x-ray. For his mutation, he swore to make Gotham pay by poisoning the water supply. This plan was foiled by the timely intervention of Gotham's protector, Batman, but Phosphorus escaped from the vigilante and contacted Thorne to eliminate Batman. Batman however continued his search for Phosphorus and they eventually clashed in the nuclear power plant where everything started. During the struggle, Dr. Phosphorus fell into the nuclear reactor, creating a big explosion and he was presumed dead. During the Underworld Unleashed storyline, he is one of many villains to sell his soul to the demon Neron. In exchange for it, he is granted better control of his powers. For example, he can now wear normal clothing without it bursting into flame. In James Robinson's series Starman he is initially hired by the Mist to kill the original Starman, Ted Knight, but is defeated by the retired hero. They face each other a second time; this time, Phosphorus has given Knight a significant dose of radiation, which gave him terminal disease. In a third and final confrontation, Knight is determined to ensure that Phosphorus would harm no one else. During the battle, he uses his cosmic rod to tear the pavement from beneath Phosphorus and drive him into the earth, apparently killing him. Phosphorus returns in Detective Comics #825, where he is being held in Cadmus Research laboratories. When one of the scientists examining him says he heard Sartorius had died, the other