The roots of renal physiology in Germany in the last century have been traced. Vitalistic concepts became replaced by physical, chemical and mechanistic laws which govern biological processes. First, the main exponents of renal physiology, J. Henle, C. Ludwig and R.P.H. Heidenhain, are discussed, then the (indirect) contributions of A. Fick, K. Peter, H. Helmholtz, E. du Bois-Reymond, J.L. Schönlein and A. Dohrn are evaluated. The original literature bearing on renal physiology in the 19th century is screened by a survey of publications in <i>Pflügers Archiv</i> and <i>Archiv der experimentellen Pathologie und Pharmakologie</i>. We point to the international cooperation in the field. At the turn of the century, renal function was adequately described by a theory of glomerular filtration, tubular secretion and tubular reabsorption.