PSM V50 D330 Wilhem Pfeffer professor of botany tubingen

Wilhelm Friedrich Philipp Pfeffer (9 March 1845 – 31 January 1920) was a German

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

and plant physiologist born in

Grebenstein Grebenstein () is a town in the district of Kassel, in Hesse, Germany. It is located 16 km northwest of Kassel on the German Timber-Frame Road. In 1762 it was the scene of a skirmish between British and French troops during the Seven Years' ...

Academic career

He studied

chemistry Chemistry is the science, scientific study of the properties and behavior of matter. It is a natural science that covers the Chemical element, elements that make up matter to the chemical compound, compounds made of atoms, molecules and ions ...

and

pharmacy Pharmacy is the science and practice of discovering, producing, preparing, dispensing, reviewing and monitoring medications, aiming to ensure the safe, effective, and affordable use of medicines. It is a miscellaneous science as it links heal ...

at the

University of Göttingen The University of Göttingen, officially the Georg August University of Göttingen, (german: Georg-August-Universität Göttingen, known informally as Georgia Augusta) is a public research university in the city of Göttingen, Germany. Founded ...

, where his instructors included

Friedrich Wöhler Friedrich Wöhler () FRS(For) HonFRSE (31 July 180023 September 1882) was a German chemist known for his work in inorganic chemistry, being the first to isolate the chemical elements beryllium and yttrium in pure metallic form. He was the firs ...

(1800-1882), William Eduard Weber (1804-1891) and

Wilhelm Rudolph Fittig Wilhelm Rudolph Fittig (6 December 183519 November 1910) was a German chemist. He discovered the pinacol coupling reaction, mesitylene, diacetyl and biphenyl. Fittig studied the action of sodium on ketones and hydrocarbons. He discovered the Fitt ...

(1835-1910). Afterwards, he furthered his education at the universities of

Marburg Marburg ( or ) is a university town in the German federal state (''Bundesland'') of Hesse, capital of the Marburg-Biedenkopf district (''Landkreis''). The town area spreads along the valley of the river Lahn and has a population of approximate ...

and

Berlin Berlin ( , ) is the capital and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitue ...

. At Berlin, he studied under

Alexander Braun Alexander Carl Heinrich Braun (10 May 1805 – 29 March 1877) was a German botanist from Regensburg, Bavaria. His research centered on the morphology of plants. Biography He studied botany in Heidelberg, Paris and Munich. In 1833 he began teachi ...

(1805-1877) and was an assistant to

Nathanael Pringsheim Nathanael Pringsheim (30 November 1823 – 6 October 1894) was a German botanist. Biography Nathanael Pringsheim was born at Landsberg, Prussian Silesia, and studied at the universities of Breslau, Leipzig, and Berlin successively. He graduat ...

(1823-1894). Later on, he served as an assistant to

Julius von Sachs Julius von Sachs (; 2 October 1832 – 29 May 1897) was a German botanist from Breslau, Prussian Silesia. He is considered the founder of experimental plant physiology and co-founder of modern water culture. Julius von Sachs and Wilhelm Knop a ...

(1832-1897) at

Würzburg Würzburg (; Main-Franconian: ) is a city in the region of Franconia in the north of the German state of Bavaria. Würzburg is the administrative seat of the ''Regierungsbezirk'' Lower Franconia. It spans the banks of the Main River. Würzburg is ...

, In 1873 he was appointed professor of

pharmacology Pharmacology is a branch of medicine, biology and pharmaceutical sciences concerned with drug or medication action, where a drug may be defined as any artificial, natural, or endogenous (from within the body) molecule which exerts a biochemica ...

and botany at the

University of Bonn The Rhenish Friedrich Wilhelm University of Bonn (german: Rheinische Friedrich-Wilhelms-Universität Bonn) is a public research university located in Bonn, North Rhine-Westphalia, Germany. It was founded in its present form as the ( en, Rhine U ...

, followed by professorships at the Universities of

Basel , french: link=no, Bâlois(e), it, Basilese , neighboring_municipalities= Allschwil (BL), Hégenheim (FR-68), Binningen (BL), Birsfelden (BL), Bottmingen (BL), Huningue (FR-68), Münchenstein (BL), Muttenz (BL), Reinach (BL), Riehen (BS ...

(from 1877) and

Tübingen Tübingen (, , Swabian: ''Dibenga'') is a traditional university city in central Baden-Württemberg, Germany. It is situated south of the state capital, Stuttgart, and developed on both sides of the Neckar and Ammer rivers. about one in thr ...

(from 1878), where he also served as director of the

Botanischer Garten der Universität Tübingen The Botanischer Garten der Universität Tübingen, also known as the Botanischer Garten Tübingen or the Neuer Botanischer Garten Tübingen, is a botanical garden and arboretum maintained by the University of Tübingen. It is located at Hartmeye ...

. In 1887 he became a professor at the

University of Leipzig Leipzig University (german: Universität Leipzig), in Leipzig in Saxony, Germany, is one of the world's oldest universities and the second-oldest university (by consecutive years of existence) in Germany. The university was founded on 2 Decemb ...

and director of its

botanical garden A botanical garden or botanic gardenThe terms ''botanic'' and ''botanical'' and ''garden'' or ''gardens'' are used more-or-less interchangeably, although the word ''botanic'' is generally reserved for the earlier, more traditional gardens, an ...

. He was elected a member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special ...

in 1897.

Scientific work

Pfeffer was a pioneer of modern

plant physiology Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology (structure of plants), plant ecology (interactions with the environment), phytochemistry (bi ...

. His scientific interests included the thermonastic and photonastic movements of flowers, the

nyctinastic Nyctinasty is the circadian rhythmic nastic movement of higher plants in response to the onset of darkness, or a plant "sleeping". Nyctinastic movements are associated with diurnal light and temperature changes and controlled by the circadian clo ...

movements of leaves, protoplastic physics and

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

. In 1877, while researching

plant metabolism Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology (structure of plants), plant ecology (interactions with the environment), phytochemistry (bio ...

, Pfeffer developed a semi-porous membrane to study the phenomena of

osmosis Osmosis (, ) is the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential (region of lower solute concentration) to a region of low water potential (region of ...

. The eponymous "Pfeffer cell" is named for the osmometric device he constructed for determining the

osmotic pressure Osmotic pressure is the minimum pressure which needs to be applied to a solution to prevent the inward flow of its pure solvent across a semipermeable membrane. It is also defined as the measure of the tendency of a solution to take in a pure ...

of a solution. During his tenure at Leipzig, Pfeffer published an article on the use of

photography Photography is the art, application, and practice of creating durable images by recording light, either electronically by means of an image sensor, or chemically by means of a light-sensitive material such as photographic film. It is employed ...

to study plant growth. He wanted to extend the chronophotographic experiments of

Étienne-Jules Marey Étienne-Jules Marey (; 5 March 1830, Beaune, Côte-d'Or – 15 May 1904, Paris) was a French scientist, physiologist and chronophotographer. His work was significant in the development of cardiology, physical instrumentation, aviation, cinema ...

(1830-1904) by producing a short film involving the stages of plant growth. This "movie" would be filmed over a period of weeks by frame-at-a-time exposure taken at regular spaced intervals. Later,

time-lapse photography Time-lapse photography is a technique in which the frequency at which film frames are captured (the frame rate) is much lower than the frequency used to view the sequence. When played at normal speed, time appears to be moving faster and thus ...

would become a commonplace procedure.Who's Who of Victorian Cinema
at www.victorian-cinema.net

Written works

* ''Physiologische Untersuchungen'' - 1873 (Physiological studies) * ''Lehrbuch der Pflanzenphysiologie'' (Textbook of plant physiology). * ''Die periodischen Bewegungen der Blattorgane'' - 1875 (The periodic movements of "leaf organs") * ''Osmotische Untersuchungen – Studien zur Zellmechanik'' - 1877 (Osmotic studies) * ''Beiträge zur Kenntniss der Oxydationsvorgänge in lebenden Zellen'' - 1889 (Contributions to the knowledge of the

oxidative Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...

processes in living cells). * ''Über Aufnahme und Ausgabe ungelöster Körper'' - 1890 * ''Studien zur Energetik der Pflanze'' - 1892 (Studies on the energetics of plants) * ''Druck- und Arbeitsleistung durch wachsende Pflanzen'' - 1893 * ''Untersuchungen über die Entstehung der Schlafbewegungen der Blattorgane'' - 1907 * ''Der Einfluss von mechanischer Hemmung und von Belastung auf die Schlafbewegung'' - 1911 (The influence of mechanical stress on the inhibition of sleep and movement). * ''Beiträge zur Kenntniss der Entstehung der Schlafbewegungen''- 1915 (Contributions to the knowledge on the genesis of sleep movements).

References

* List of publications copied from an equivalent article at the

German Wikipedia The German Wikipedia (german: Deutschsprachige Wikipedia) is the German-language edition of Wikipedia, a free and publicly editable online encyclopedia. Founded on March 16, 2001, it is the second-oldest Wikipedia (after the English Wikipedia), ...

. {{DEFAULTSORT:Pfeffer, Wilhelm 1845 births 1920 deaths People from Grebenstein 19th-century German botanists University of Göttingen alumni University of Bonn faculty Members of the Royal Swedish Academy of Sciences Recipients of the Pour le Mérite (civil class) Fellows of the Royal Society Foreign associates of the National Academy of Sciences University of Tübingen faculty University of Basel faculty Leipzig University faculty Plant physiologists People from Mansfeld-Südharz Members of the Royal Society of Sciences in Uppsala