Julius Sachs

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Julius Sachs

Julius Sachs or Julius von Sachs (born October 2, 1832 in Breslau , † May 29, 1897 in Würzburg ) was a Prussian-Silesian , German botanist . He is regarded as the founder of experimental plant physiology . Its official botanical author's abbreviation is " Sachs ".

Life

Sachs was born into a Jewish family as the seventh child of an engraver. He grew up in very modest circumstances, it was not possible for his parents to train their son according to his genius. At least he was able to go to high school.

As a teenager, Sachs received his first suggestions for the natural sciences from the Breslau physiologist and pathologist Jan Evangelista Purkinje , whose sons attended school with him. Through contact with them he found his sense of the beauty of nature . From an early age he collected and designated plants with great enthusiasm. After losing his father, mother and brother at the age of 17, he first decided to leave school and become a seaman. Purkinje was able to prevent him from making this decision by taking him with him as a private assistant when he moved from Breslau to Prague in 1850 .

There Sachs continued his studies and studied natural sciences at the University of Prague from 1851 . He also worked for Purkinje and obtained his doctorate in 1856. phil. He completed his habilitation in botany in 1857.

In his early work, Sachs dealt with topics related to nutritional and growth physiology. In 1859, on the recommendation of the zoologist Friedrich Ritter von Stein (1818–1885) and the botanist Friedrich Wilhelm Hofmeister , at that time still a music dealer in Leipzig , he received a position as an assistant at the agricultural technology laboratory in Tharandt . Here he succeeded in further developing the cultivation methods of plants in the laboratory and (at the same time with Wilhelm Knop ) growing plants in inorganic nutrient solutions.

Sachs researched mainly in the field of plant physiology. The main authorities in this field in his time were Hugo von Mohl , Carl Wilhelm von Nägeli and Friedrich Wilhelm Hofmeister . These were mainly concerned with studies on plant cells and tissue. With his experimental physiology , Sachs revived the earlier approaches of Stephen Hales , Thomas Andrew Knight , Nicolas Théodore de Saussure and Jean Baptiste Boussingault .

He developed the so-called auxanometer , a device for measuring plant growth.

In 1861 Sachs became professor of botany at the agricultural college in Poppelsdorf near Bonn . During the six years that he worked there, he was able to prove, among other things, that starch , which is formed by carbonic acid assimilation in the chlorophyll grains, disappears in the dark and reappears in the light. He provided this evidence with the known iodine sample .

It was also during this period that Sachs was shown to be an excellent botanical writer. On October 1, 1865, he published the "Handbuch der Experimentalphysiologie", which contained a clear overview of interesting and important experiments on plant physiology. This enabled Sachs to make this subject known to a broad specialist public.

In 1867 he succeeded Heinrich Anton de Bary at the Albert Ludwig University in Freiburg im Breisgau. He hardly stayed there for a year because of the poor working conditions. In 1868 he followed a call to the University of Würzburg , where he worked for over 30 years despite numerous calls to other universities (including Jena , Heidelberg , Vienna , Berlin , Bonn and Munich ). Among other things, Sachs researched the branching of roots, which led him to the physiology of germination. He made a significant contribution to the clarification of the photosynthesis processes and in developmental physiological studies concluded the presence of "flower-forming substances", a hypothesis that was only taken up and confirmed again half a century later.

In addition to his many other works in the field of plant physiology (for example stimulus physiology), Sachs was interested and committed to other areas of botany and biology. He commented, for example, on the phylogenetic history of plants and on the theory of descent by Charles Darwin , whose formulation of a selection principle he considered an inadequate explanation for evolution.

His position on species protection is remarkable: He made the following statements on this topic as early as the end of the 19th century:

“It has always struck me as strange that even natural scientists watch the extermination of typical figures with a cool expression; If one considers that every organic form, according to its phylogenetic origin, was a historical event which can never be repeated, then its eradication has created a void for all eternity in the organic world, and that is no small matter, even if it does are not giant birds, but only microscopic species. "

Many of Sachs' students later became famous botanists, including Julius Oscar Brefeld , Francis Darwin (1848–1925), Karl Ritter von Goebel , Georg Albrecht Klebs , Spiridon Miliarakis , Hermann Müller-Thurgau , Gregor Kraus , Fritz Noll (1858–1908), Wilhelm Pfeffer , Karl Prantl , Ernst Stahl , Hugo de Vries and Otto Appel .

Fonts (selection)

  • 1859: Physiological studies on the germination of the makeup bean ( Phaseolus multiflorus ).
  • 1859: About the alternating pale and darkening of the leaves with changing lighting.
  • 1862: About the decay of plants.
  • 1863: About the influence of daylight on the new formation and development of various plant organs.
  • 1865: Handbuch der Experimentalphysiologie der Pflanzen.
  • 1868: Textbook of botany.
  • 1871–1872: The history of botany from the 16th century to 1860.
  • 1872: About the current state of botany in Germany. Speech to celebrate the 290th anniversary of the foundation of the Julius Maximilians University, delivered […] on January 2, 1872. Thein, Würzburg 1872.
  • 1875: History of botany from the 16th century to 1860. Oldenbourg, Munich 1875; Reprint Olms, Hildesheim 1966 (= history of science in Germany. Volume 15). Digitized edition of the University and State Library Düsseldorf ; Digitized and full text in the German text archive
  • 1882: Lectures on plant physiology. Engelmann, Leipzig 1882.
  • 1892: Collected treatises on plant physiology.
  • 1894: Mechanomorphoses and Phylogeny.
  • 1896: Phylogenetic aphorisms and about internal design causes or automorphoses.

honors and awards

In 1874 he became a corresponding member of the Bavarian Academy of Sciences , in 1880 a foreign member . In 1880 he was elected a member of the Leopoldina , in 1882 Sachs was elected to the American Academy of Arts and Sciences and on May 31, 1888 to a foreign member of the Royal Society . Since 1895 he was a member of the National Academy of Sciences .

literature

Web links

Individual evidence

  1. ↑ See Hans Burgeff : Sachs and the experiment. In: Negotiations of the Physico-Medical Society. New episode. Volume 57, 1932, pp. 41-51. See also Ernst G. Pringsheim : Julius Sachs, the founder of the new plant physiology, 1832–1897. Fischer, Jena 1932.
  2. ↑ quoted in Mägdefrau 1992: 262.
  3. ↑ Member entry by Prof. Dr. Julius von Sachs (with picture) at the Bavarian Academy of Sciences , accessed on February 8, 2016.
  4. ↑ Member entry of Julius von Sachs at the German Academy of Natural Scientists Leopoldina , accessed on February 8, 2016.
  5. ^ Members of the American Academy. Listed by election year, 1850–1899 ( PDF ) Retrieved September 24, 2015.
  6. ^ Entry on Sachs, Julius von (1832–1897) in the archive of the Royal Society , London .
personal data
SURNAME Sachs, Julius
BRIEF DESCRIPTION German botanist and is considered the founder of experimental plant physiology
DATE OF BIRTH October 2, 1832
PLACE OF BIRTH Wroclaw
DATE OF DEATH May 29, 1897
Place of death Wurzburg