"Ruminating about Problems in Plant Physiology"
Many scientists strive for professorship. Also in former times. At that time it often was sufficient to be a student of Wilhelm Pfeffer to be appointed to a university.
Upon starting his career as a pharmacist in the drug store of his father in Switzerland Pfeffer analyzed plant cells in the microscope and collected his objects. After finishing the education in the pharmacy, he studied chemistry and physics at the University of Göttingen, Germany.
Having a PhD at 20
After only two years of studies at the age of 20, Pfeffer wrote his PhD thesis about derivatives of glycerol. In Marburg. germany, Pfeffer analyzed the synthesis of Flowers in Primulaceae.
From Flowers to Photosynthesis
Subjects of his "Habilitationsschrift" in 1871 were experiments on the opening and closing of flowers. At the University of Würzburg Pfeffer specialized in plant physiology especially in photosynthesis.
Appointment in Leipzig
In 1873 he was appointed "Extraordinarius" ("Assistant Professor") in Bonn, Germany. Four years later he went for a Full Professorship to Basel, Switzerland, and another year later to Tübingen, Germany. Already at that time he had many students. In 1887 he followed his final appointment in Leipzig, Germany, where he worked until his death in 1920.
Not to Make a Fool of Himself
Pfeffer was a reserved and cautious person, constantly trying not to show his weak points and not "to make a fool of himself" as he called his endeavors. On the other side, his research in plant physiology was highly diverse. He analyzed the nastic movements of Mimosa and described the "high hydrostatic power" driving the plant's movements in his famous "Osmotic Analyses" ("Osmotische Untersuchungen", 1877).
The results about the chemotaxis of spermatozoids, flagellates, and bacteria are still part of the textbooks in botany. His scientific interests were also the physics of protoplasts (e.g. Pfeffer's cell), the nyctinastic movements of leaves, and the thermo- and photonastic movements of flowers.
Founder of modern plant physiology
Through the two volumes of his "Textbook of Plant Physiology" ("Lehrbuch der Pflanzenphysiologie") which was translated in English and French he rose to an international teacher of botany. Today he is thought to be one of the founder of modern plant physiology.
Wise and deep confinement
"Pfeffer's mastership can be seen in his wise confinement which he chose intentionally, ....., and in the depth of investigation which is only possible through that narrow view" wrote Hans Fittig Pfeffer's professor in chemistry. "Constantly ruminating about problems in plant physiology he was able to sense their whole width and deepness".
Successful students from the "Mekka for Plant Physiologists"
His Institut in Leipzig soon became a "Mekka for plant physiologists", Mägdefrau wrote. Many botanists worked with him as post docs. A pamphlet on the occasion of his 70th birthday lists 260 students who worked with him and who came from all over the world. About 100 of them later became professors at universities themselves.
Text and Copyright: Dr. Esther Schwarz-Weig
 Mägdefrau, K.: "Geschichte der Botanik. Leben und Leistung großer Forscher" (Stuttgart, Gustav Fischer Verlag, 2. Auflage, 1992).