Wilhelm Pfeffer
Encyclopedia
Wilhelm Friedrich Philipp Pfeffer (9 March 1845 - 31 January 1920) was a German botanist and plant physiologist
who was born in Grebenstein
.
and pharmacology
at the University of Göttingen under Friedrich Wöhler
(1800-1882), William Eduard Weber (1804-1891) and Wilhelm Rudolph Fittig
(1835-1910). Afterwards he furthered his education at the Universities of Marburg and Berlin. At Berlin he studied under Alexander Braun
(1805-1877) and was an assistant to Nathanael Pringsheim
(1823-1894). He later worked as an assistant to Julius von Sachs
(1832-1897) at Würzburg
, and in 1873 became a professor of pharmacology and botany at the University of Bonn
. Later he worked as a professor at the Universities of Basel
(from 1877), Tübingen (from 1878), where he served as director of the Botanischer Garten der Universität Tübingen
, and Leipzig
(from 1887), where he was director of the Leipzig Botanical Garden
.
He was elected a member of the Royal Swedish Academy of Sciences
in 1897.
. His scientific interests included the thermonastic and photonastic movements of flowers, the nyctinastic movements of leaves, protoplast
ic physics and photosynthesis
. In 1877, while researching plant metabolism
, Pfeffer developed a semi-porous membrane to study the phenomena of osmosis
. The eponymous "Pfeffer cell" is named after the osmometric
device he constructed to determine the osmotic pressure
of a solution.
During his tenure at Leipzig, Pfeffer published an article on the use of photography
to study plant growth. He wanted to extend the chronophotographic
experiments of Étienne-Jules Marey
(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 would become a commonplace procedure.
Plant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
who was born in Grebenstein
Grebenstein
Grebenstein is a town in the district of Kassel, in Hesse, Germany. It is located 16 km northwest of Kassel on the German Framework Road. In 1762 it was the scene of a skirmish between British and French troops during the Seven Years War.-External links:...
.
Academic career
He studied botany, physicsPhysics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and pharmacology
Pharmacology
Pharmacology is the branch of medicine and biology concerned with the study of drug action. More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function...
at the University of Göttingen under Friedrich Wöhler
Friedrich Wöhler
Friedrich Wöhler was a German chemist, best known for his synthesis of urea, but also the first to isolate several chemical elements.-Biography:He was born in Eschersheim, which belonged to aau...
(1800-1882), William Eduard Weber (1804-1891) and Wilhelm Rudolph Fittig
Wilhelm Rudolph Fittig
Wilhelm Rudolph Fittig was a German chemist. Fittig discovered the pinacol coupling reaction, mesitylene, diacetyl and biphenyl. He studied the action of sodium on ketones and hydrocarbons...
(1835-1910). Afterwards he furthered his education at the Universities of Marburg and Berlin. At Berlin he studied under Alexander Braun
Alexander Braun
Alexander Carl Heinrich Braun was a German botanist from Regensburg, Bavaria.He studied botany in Heidelberg, Paris and Munich. In 1833 he began teaching botany at the Polytechnic School of Karlsruhe, staying there until 1846...
(1805-1877) and was an assistant to Nathanael Pringsheim
Nathanael Pringsheim
Nathanael Pringsheim was a German botanist.-Biography:Nathanael Pringsheim was born at Landsberg, Prussian Silesia, and studied at the universities of Breslau, Leipzig, and Berlin successively...
(1823-1894). He later worked as an assistant to Julius von Sachs
Julius von Sachs
Julius von Sachs was a German botanist from Breslau, Prussian Silesia.At an early age he showed a taste for natural history, becoming acquainted with the Breslau physiologist Jan Evangelista Purkyně. In 1851 he began studying at Charles University in Prague...
(1832-1897) at Würzburg
Würzburg
Würzburg is a city in the region of Franconia which lies in the northern tip of Bavaria, Germany. Located at the Main River, it is the capital of the Regierungsbezirk Lower Franconia. The regional dialect is Franconian....
, and in 1873 became a professor of pharmacology and botany at the University of Bonn
University of Bonn
The University of Bonn is a public research university located in Bonn, Germany. Founded in its present form in 1818, as the linear successor of earlier academic institutions, the University of Bonn is today one of the leading universities in Germany. The University of Bonn offers a large number...
. Later he worked as a professor at the Universities of Basel
University of Basel
The University of Basel is located in Basel, Switzerland, and is considered to be one of leading universities in the country...
(from 1877), Tübingen (from 1878), where he served as director of the Botanischer Garten der Universität Tübingen
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...
, and Leipzig
University of Leipzig
The University of Leipzig , located in Leipzig in the Free State of Saxony, Germany, is one of the oldest universities in the world and the second-oldest university in Germany...
(from 1887), where he was director of the Leipzig Botanical Garden
Leipzig Botanical Garden
Leipzig Botanical Garden , , is a botanical garden maintained by the University of Leipzig, and located at Linnéstraße 1, Leipzig, Saxony, Germany. It is the oldest botanical garden in Germany and among the oldest in the world, and open daily without charge.Leipzig's botanical garden dates back to...
.
He was elected a member of the Royal Swedish Academy of Sciences
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
in 1897.
Scientific work
Pfeffer was a pioneer of modern plant physiologyPlant physiology
Plant physiology is a subdiscipline of botany concerned with the functioning, or physiology, of plants. Closely related fields include plant morphology , plant ecology , phytochemistry , cell biology, and molecular biology.Fundamental processes such as photosynthesis, respiration, plant nutrition,...
. His scientific interests included the thermonastic and photonastic movements of flowers, the nyctinastic movements of leaves, protoplast
Protoplast
Protoplast, from the ancient Greek πρῶτον + verb πλάθω or πλάττω , initially referred to the first organized body of a species.Protoplast has several biological definitions:...
ic physics and photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
. In 1877, while researching plant metabolism
Metabolism
Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...
, Pfeffer developed a semi-porous membrane to study the phenomena of osmosis
Osmosis
Osmosis is the movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, aiming to equalize the solute concentrations on the two sides...
. The eponymous "Pfeffer cell" is named after the osmometric
Osmometer
An osmometer is a device for measuring the osmotic strength of a solution, colloid, or compound.There are several different techniques employed in osmometry:...
device he constructed to determine the osmotic pressure
Osmotic pressure
Osmotic pressure is the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane....
of a solution.
During his tenure at Leipzig, Pfeffer published an article on the use of photography
Photography
Photography is the art, science and practice of creating durable images by recording light or other electromagnetic radiation, either electronically by means of an image sensor or chemically by means of a light-sensitive material such as photographic film...
to study plant growth. He wanted to extend the chronophotographic
Chronophotography
Chronophotography is an antique photographic technique from the Victorian era , which captures movement in several frames of print. These prints can be subsequently arranged either like animation cels or layered in a single frame...
experiments of Étienne-Jules Marey
Étienne-Jules Marey
Étienne-Jules Marey was a French scientist and chronophotographer.His work was significant in the development of cardiology, physical instrumentation, aviation, cinematography and the science of labor photography...
(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 would become a commonplace procedure.