By 1740, Hartley was known to every physician in London and to other medical men throughout Europe. He had thrown himself into a controversial attempt to harmonize private interest and public good. Hartley had started to experience symptoms of "the stone" (bladder stone) in early 1736. A bladder stone, sometimes as large as an egg, could function as a ball-cock on a toilet tank, causing an inability to urinate, excruciating pain, and sometimes death. (Benjamin Franklin, a sufferer, sometimes had to stand on his head to relieve himself.) Treatment by surgical removal (lithotomy) was a procedure many failed to survive.