Franz Volhard (1872-1950), German physician. Volhard was principally interested in renal (kidney) disease. In 1914 he published a paper with Theodor Fahr, in which renal diseases were differentiated for the first time. They classified the diseases into either degenerative (nephroses), inflammatory (nephritides) or arteriosclerotic (scleroses; hardening of the blood vessels). He also made significant contributions outside of nephrology. He discovered lipase in the heart and kidneys and described how the enzyme aided the digestion of fat. He also discovered the decomposing ferment in the heart and kidneys.