J. v. Sachs is the founder of the experimental approach to plant physiology. He invented and constructed numerous devices for the study and quantitative analysis of plant physiological processes. Besides, he is the author of several standard works, like "Lehrbuch der Botanik" (A textbook on botany; 1. to 4. edition: 1868, 1870, 1873, 1874), "Vorlesungen ber Pflanzenphysiologie" (Lectures on Plant Physiology; 1882, 1887), "Geschichte der Botanik" (A History of Botany; 1875). Until today, his illustrations of his work remain a definite part of botanical textbooks. After Prague, Tharandt (near Dresden), Bonn and shortly also Freiburg, the German town of Wrzburg became his most important domain (University Library of Wrzburg)