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 are monumental figures in the
history of botany
The history of botany examines the human effort to understand life on Earth by tracing the historical development of the discipline of botany—that part of natural science dealing with organisms traditionally treated as plants.
Rudimentary b ...
by first demonstrating the importance of water culture for the study of
plant nutrition and plant physiology in the
19th century.
Early life
Sachs was born at Breslau on 2 October 1832. His father, Graveur Sachs, was an engraver by trade, and father taught son delineation and accuracy of line and color. From earliest boyhood Julius was fascinated with plants, making collections of them on many field excursions with his father. He gave much of his time between the ages of thirteen and sixteen to drawing and painting the flowers, fungi, and other specimens which he collected. At the Gymnasium from 1845 to 1850 he was most interested in the natural sciences, collecting skulls, writing a monograph on the crayfish. His natural science teacher, one Krober, showed a singular lack of foresight when he solemnly warned young Sachs against devoting himself to the natural sciences.
When he was sixteen years old, his father died, and in the next year both his mother and a brother died of cholera. Suddenly without financial support, he was fortunate to be taken into the family of
Jan Evangelista Purkyně
Jan Evangelista Purkyně (; also written Johann Evangelist Purkinje) (17 or 18 December 1787 – 28 July 1869) was a Czech anatomist and physiologist. In 1839, he coined the term '' protoplasm'' for the fluid substance of a cell. He was one of ...
who had accepted a professorship at the
University of Prague. Sachs was admitted to the university in 1851.
Sachs famously labored long hours in the laboratory for Purkyně, and then long hours for himself each day after his work in the laboratory was finished. After the lab, he could devote himself entirely to establishing how plants grow.
Career
In 1856 Sachs graduated as doctor of philosophy, and then adopted a botanical career, establishing himself as ''
Privatdozent'' for
plant physiology. In 1859 he was appointed physiological assistant to the Agricultural Academy of Tharandt (now part of the
Technical University of Dresden) at
Julius Adolph Stöckhardt; and in 1862 he was called to be director of the
Polytechnic at Chemnitz, but was almost immediately transferred to the Agricultural Academy at Poppelsdorf (now part of the
University of Bonn), where he remained until 1867, when he was nominated professor of botany in the
University of Freiburg.
In 1868 he accepted the chair of botany in the
University of Würzburg, which he continued to occupy (in spite of calls from more prestigious German universities) until his death.
Sachs achieved distinction as an investigator, a writer and a teacher; his name will ever be especially associated with the great development of plant physiology which marked the latter half of the 19th century, though there is scarcely a branch of botany to which he did not materially contribute. His earlier papers, scattered through the volumes of botanical journals and of the publications of learned societies (a collected edition was published in 1892–93), are of great and varied interest. Prominent among them is the series of "Keimungsgeschichten," which laid the foundation of our knowledge of microchemical methods, as also of the
morphological and physiological details of
germination.
Then there is his resuscitation of the method of "water-culture," and the application of it to the investigation of the problems of nutrition.
Most important are his experiments, developing the concept of
photosynthesis, that the
starch-grains, found in leaf
chloroplasts
A chloroplast () is a type of membrane-bound organelle known as a plastid that conducts photosynthesis mostly in plant and algal cells. The photosynthetic pigment chlorophyll captures the energy from sunlight, converts it, and stores it in ...
, depend on sunlight. A leaf that has been in sunlight, then bleached white and stained with
iodine turns black, proving its starch content, whereas a leaf from the same plant that has been out of the sun will remain white. A demonstration of this experiment is shown in the second episode of
BBC Four's "Botany: A Blooming History" presented by
Timothy Walker.
Sachs's later papers were almost exclusively published in the three volumes of the ''Arbeiten des botanischen Instituts in Würzburg'' (1871–88). Among these are his investigation of the periodicity of growth in length, in connection with which he devised the self-registering
auxanometer
An auxanometer (Gr. '= "to grow" + ''metron''= "measure") is an apparatus for measuring increase of growth in plants.
In case of an arc-auxanometer (see picture), there is a thin cord fixed to the plant apex on one end and a dead-weight on the oth ...
, by which he established the retarding influence of the highly refrangible rays of the
spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...
on the rate of growth; his research on
heliotropism and
geotropism, in which he introduced the
clinostat; his work on the structure and the arrangement of cells in growing-points; the elaborate experimental evidence upon which he based his "imbibition-theory" of the transpiration-current; his exhaustive study of the assimilatory activity of the green
leaf
A leaf ( : leaves) is any of the principal appendages of a vascular plant stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, ste ...
; and other papers of interest.
Sachs' first published volume was the ''Handbuch der Experimentalphysiologie des Pflanzen'' (1865; French edition, 1868), which gives an admirable account of the state of knowledge in certain departments of the subject, and includes a great deal of original information. This was followed in 1868 by the first edition of his famous ''Lehrbuch der Botanik''. It is a comprehensive work, giving a summary of the botanical science of the period, enriched with the results of many original investigations. The third edition was translated into French by
Philippe Édouard Léon Van Tieghem
Philippe Édouard Léon Van Tieghem (; 19 April 1839 – 28 April 1914) was a French botanist born in Bailleul, Nord, Baillleul in the département of Nord (French department), Nord. He was one of the best known French botanists of the latter nin ...
in 1873, and into English by Alfred Bennett in 1875, and published by Oxford University Press. The fourth and last German edition was published in 1874, and also issued by Oxford in 1882.
The ''Lehrbuch'' was eventually superseded by the ''Vorlesungen uber Pflanzenphysiologie'' (1st ed., 1882; 2nd ed., 1887; Eng. ed., Oxford, 1887), a work more limited in scope, but covering more ground than its title would imply; it has not gained the general recognition accorded to the ''Lehrbuch''. Finally, there is the ''Geschichte der Botanik'' (1875); an account of the development of the various branches of botanical science from the middle of the 16th century up to 1860, of which an English edition was published in 1890 by the Oxford Press.
A full account of Sachs' life and work was given by Professor Goebel, formerly his assistant, in ''Flora'' (1897), of which an English translation appeared in ''Science Progress'' for 1898. There is also an obituary notice of him in the ''Proc. Roy. Soc.'' vol. lxii.
In 1885 he became foreign member of the
Royal Netherlands Academy of Arts and Sciences.
Evolution
Sachs has been described as a "post-Darwinian botanist" who "integrated the evolutionary theory into his morphological writings." He was originally supportive of
Darwinism but in his late career became bitterly opposed to it, instead preferring
non-Darwinian evolution.
Influence
Many pupils of Sachs like
Julius Oscar Brefeld,
Francis Darwin,
Karl Ritter von Goebel,
Georg Albrecht Klebs,
Spiridon Miliarakis,
Hermann Müller-Thurgau,
Fritz Noll,
Wilhelm Pfeffer
Wilhelm Friedrich Philipp Pfeffer (9 March 1845 – 31 January 1920) was a German botanist and plant physiologist born in Grebenstein.
Academic career
He studied chemistry and pharmacy at the University of Göttingen, where his instructors incl ...
,
Karl Prantl,
Christian Ernst Stahl and
Hugo de Vries
Hugo Marie de Vries () (16 February 1848 – 21 May 1935) was a Dutch botanist and one of the first geneticists. He is known chiefly for suggesting the concept of genes, rediscovering the laws of heredity in the 1890s while apparently unaware o ...
became later famous botanists.
His scientific statements also influenced
Dennis Robert Hoagland and
Daniel Israel Arnon, who followed one of Sachs' principles in developing nutrient solutions, by quoting him as follows: "I mention the quantities (of chemicals) I am accustomed to use generally in water cultures, with the remark, however, that a somewhat wide margin may be permitted with respect to the quantities of the individual salts and the concentration of the whole solution - it does not matter if a little more or less of the one or the other salt is taken - if only the nutritive mixture is kept within certain limits as to quality and quantity, which are established by experience." Sachs' quantity and quality principle and Knop's
four-salt mixture contributed significantly to the development of the later
Hoagland solution
The Hoagland solution is a hydroponic nutrient solution that was newly developed by Hoagland and Snyder in 1933, modified by Hoagland and Arnon in 1938, and revised by Arnon in 1950. It is one of the most popular artificial solution compositions ...
.
The standard
botanical author abbreviation Sachs is applied to
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
he described.
In 1866, botanist
Griseb. published ''
Sachsia'', which is a genus of
West Indian
A West Indian is a native or inhabitant of the West Indies (the Antilles and the Lucayan Archipelago). For more than 100 years the words ''West Indian'' specifically described natives of the West Indies, but by 1661 Europeans had begun to use it ...
and
Floridian plants in the
elecampane tribe.
Then in 1895, botanist
Paul Lindner
Paul Lindner (1861 – 1945) was a German chemist and microbiologist, best known for discovering the fission yeast ''Schizosaccharomyces pombe''.
Biography and career
Lindner was born in 1861 in Giesmannsdorf near the Neisse River, part of Up ...
published ''
Sachsia'', which is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
of fungi in the
Ascomycota phylum and
Saccharomycetales
Saccharomycetales belongs to the kingdom of Fungi and the division Ascomycota. It is the only order in the class Saccharomycetes. There are currently 13 families recognized as belonging to Saccharomycetales. GBIF also includes; Alloascoideacea ...
order. Both were named in honour of Julius von Sachs.
Publications
* 1859: Physiologische Untersuchungen über die Keimung der Schmikbohne (Phaseolus multiflorus)
* 1859: Ueber das abwechselnde Erbleichen und Dunkelwerden der Blätter bei wechselnder Beleuchtung
* 1862: Ueber das Vergeilen der Pflanzen
* 1863: Ueber den Einfluss des Tageslichtes auf die Neublidung unt Entfaltung verschiedener Pflanzenorgane
* 1865: Handbuch der Experimentalphysiologie der Pflanzen
* 1868: Lehrbuch der Botanik, 3rd ed. 1873
4th ed. 1874* 1875:
Die Geschichte der Botanik vom 16. Jahrhundert bis 1860Digital edition from 1875by the
University and State Library Düsseldorf)
* 1878: Ueber die Anordnung der Zellen in jüngsten Pflanzentheilen
* 1882: Die Vorlesungen über Pflanzenphysiologie
* 1892: Gesammelte Abhandlungen über Pflanzenphysiologie
* 1894: Mechanomorphosen und Phylogenie
* 1896: Phylogenetische Aphorismen und über innere Gestaltungsursachen oder Automorphosen
References
Other sources
*
*
*
Bibliography
*
** , see also
External links
*
{{DEFAULTSORT:Sachs, Julius von
1832 births
1897 deaths
Plant physiologists
German scientists
People from Wrocław
German untitled nobility
Foreign associates of the National Academy of Sciences
Foreign Members of the Royal Society
Members of the Royal Netherlands Academy of Arts and Sciences
Charles University alumni
Academic staff of Charles University
Academic staff of the University of Freiburg
Academic staff of the University of Würzburg
Academic staff of the University of Bonn
Non-Darwinian evolution
Musicians from Wrocław
People from the Province of Silesia
Botanists with author abbreviations
19th-century German botanists
Scientists from Würzburg