The first black surgeon to do open heart surgery was Dr. Daniel Hale Williams. In 1893, he saved a man who was knifed by opening his chest and sewing together the wound, which was only a fraction of an inch from his heart. He was one of the first to do this. He accomplished this without any modern medical devices, such as x-rays.
Thomas Crapper developed the flush toilet. In 1884, he simulated the materials a toilet would normally handle, to create "a super-flush which had completely cleared away: 10 apples, 1 flat sponge, 3 air vessels, Plumbers Smudge coated over the pan, 4 pieces of paper adhering closely to the soiled surface." A fantastic feat of flushing!
