The miasma theory was advanced to explain many important diseases, including tuberculosis and malaria (from mala aria, meaning "bad air"). Many eminent leaders of medical opinion were convinced that the cholera epidemics of the nineteenth century were caused by miasmas, even as the evidence mounted for the germ theory, which was gathering momentum at that time. William Farr stated firmly in his annual report on vital statistics in Great Britain in 1852 that the inverse association of cholera mortality with elevation above sea level confirmed the miasma theory as its cause. Farr rejected John Snow's argument, based on evidence and logical reasoning, that cholera was caused by contaminated drinking water."