Wilhelm Pfeffer

from Wikipedia, the free encyclopedia
Wilhelm Pfeffer (around 1910)

Wilhelm Friedrich Philipp Pfeffer (born March 9, 1845 in Grebenstein near Kassel , † January 31, 1920 in Leipzig ) was a German botanist and plant physiologist . Its official botanical author's abbreviation is “ Pfeff. ".

Live and act

Wilhelm Pfeffer was the son of a pharmacist . First he attended the Kassel Electoral High School, then became a pharmacist apprentice and passed the assistant examination at the age of 18. His father aroused his interest in botany and natural sciences at an early age. From 1863 he studied chemistry and pharmacy at the University of Göttingen . He attended lectures in chemistry with Friedrich Wöhler , in physics with Wilhelm Eduard Weber and in chemistry with Rudolph Fittig . In the latter, he was awarded a doctorate in 1865 on the subject of " About some derivatives of glycerine and its conversion into allylene ". phil. PhD. During his studies in Göttingen he became a member of the black fraternity and later fraternity Frisia at the same time as Rudolf Eucken . He then studied pharmacy at the Philipps University of Marburg , where he joined the Marburg fraternity , later the Arminia Marburg fraternity , which awarded him a ribbon of honor in 1872.

He then worked as a pharmacist in Augsburg and from 1866 in Chur , Graubünden , where he dealt with deciduous mosses , among other things . He was introduced to alpine botany and mountaineering through his uncle, the geologist Gottfried Theobald . Pfeffer was the fifth person to climb the Matterhorn .

From 1868/69, Pfeffer studied pharmacy again at the University of Marburg and graduated with a state examination in pharmaceuticals. He then studied at the University of Berlin with Alexander Braun and Nathanael Pringsheim , with whom he was also a private assistant. Then Pfeffer went to Würzburg as Julius von Sachs' private assistant .

He completed his habilitation in 1871. Works from this time were The Effect of Colored Light on the Decomposition of Carbonic Acid in Plants and “The Development of the Germ of the Genus Selaginella ”. After a stopover as a private lecturer at the University of Marburg, Pfeffer worked from 1873 as an associate professor for pharmacognosy and botany at the University of Bonn . In 1877 Pfeffer became a full professor at the University of Basel and in 1878 at the University of Tübingen . In 1880, Pfeffer became a corresponding member of the Bavarian Academy of Sciences . Also in 1880 he was elected a member of the Leopoldina . Later he also belonged to the Royal Saxon Society of Sciences (from 1887), the Prussian Academy of Sciences (from 1889), the Royal Society of Sciences in Uppsala (from 1894), the Royal Physiographical Society in Lund (from 1895), the Royal Swedish Academy of Sciences , the American Academy of Arts and Sciences (both from 1897), the Académie des sciences (from 1900), the Göttingen Academy of Sciences (from 1902), the National Academy of Sciences (from 1903) and the Russian Academy of the sciences (from 1908). In 1910 he received the Cothenius Medal of the Leopoldina.

In 1887 he received a call to the University of Leipzig , where he became professor of botany and director of the botanical garden .

Inspired by Julius von Sachs during his time in Würzburg, Pfeffer examined, among other things, the effect of different colored light on carbon dioxide assimilation. Then, while working on cell membranes , he came across the phenomenon of osmosis , which the physicist Abbé Jean Antoine Nollet had discovered in 1748.

Pfeffer did his osmotic examinations in his private apartment, as there were no suitable rooms at the institute. In doing so, he developed the Pfeffer's cell named after him , a membrane osmometer . This measuring device consisted of a clay cell, the porous walls of which were covered with the semipermeable precipitation membranes described by Moritz Traube in 1867 . The Pfeffer's cell made it possible for the first time to quantitatively determine the osmotic pressure of aqueous solutions.

Jacobus Henricus van 't Hoff later investigated the laws of dilute solutions on the basis of Pfeffer's findings. In 1901 he received the first Nobel Prize in Chemistry .

Pfeffer studied many other botanical phenomena, including the movement of the stamens of Centaurea species and chemotactic movements of spermatozoa in mosses and ferns, as well as the daily rhythms of leaf and flower movements and the saccharification of corn seedlings.

Together with Julius von Sachs, Wilhelm Pfeffer is considered to be the founder of modern plant physiology.

His library of over 11,700 volumes and reprints was bought in Japan ( Kurashiki , owned by Okayama University ).

student

Numerous students of Wilhelm Pfeffer later became well-known botanists themselves. These were:

Wilhelm Pfeffer Prize

The German Botanical Society has been awarding the Wilhelm Pfeffer Prize through the Wilhelm Pfeffer Foundation since 1992 . The foundation honors young scientists with the prize, which is endowed with 2,500 euros, for special merits in the field of plant sciences.

Fonts

  • Physiological studies . 1873
  • The periodic movements of the leaf organs . 1875
  • Osmotic studies . 2. unchangeable Edition 1921 (first edition 1877)
  • Contributions to the knowledge of the oxidation processes in living cells . 1889
  • About the absorption and release of unresolved bodies . 1890
  • Studies on the energetics of the plant . 1892
  • Pressure and work performance from growing plants . 1893
  • Investigations into the origin of the sleep movements of the leaf organs . 1907
  • The influence of mechanical inhibition and stress on sleep movement . 1911
  • Contributions to the knowledge of the origin of sleep movements . 1915

literature

Web links

Individual evidence

  1. ^ Member entry of Wilhelm Pfeffer at the German Academy of Natural Scientists Leopoldina , accessed on January 21, 2016.
  2. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 189.
  3. ^ Wilhelm Pfeffer. Osmotic studies . Wilh. Engelmann, Leipzig 1921. (2nd, unchanged edition of the first print from 1877)
  4. ^ A. Hager (1995) laudation for honorary membership for Masashi Tazawa Botanica Acta of the German Botanical Society
personal data
SURNAME Pfeffer, Wilhelm
ALTERNATIVE NAMES Pfeffer, Wilhelm Friedrich Philipp (full name)
BRIEF DESCRIPTION German botanist and plant physiologist
DATE OF BIRTH March 9, 1845
PLACE OF BIRTH Grebenstein near Kassel
DATE OF DEATH January 31, 1920
Place of death Leipzig