SACHS, JULIUS VON (1832-1897), German botanist, was born at Breslau on Oct. 2, 1832. On leaving school in 1851 he became assistant to the physiologist J. E. Purkinje at Prague.
In 1856 he graduated as doctor of philosophy, and established himself as Privatdozent for plant physiology in the university of Prague. In 1859 he was appointed physiological assistant to the Agricultural Academy of Tharandt in Saxony; and in 1861 he went to the Agricultural Academy at Poppelsdorf, near Bonn, where he remained until 1867, when he was nominated professor of botany in the university of Freiburg-im-Breisgau. In 1868 he accepted the chair of botany in the university of Wiirzburg, which he continued to occupy until his death on May 29, 1897.
Sachs was especially associated with the development of plant physiology which marked the latter half of the 19th century, though he contributed to every branch of botany. His earlier papers, in botanical journals and publications of learned societies, are of interest. Prominent among them is the series of "Keimungs geschichten," which laid the foundation of our knowledge of micro chemical methods, and the morphological and physiological de tails of germination. Then there is his resuscitation of the method of "water-culture," and its application to problems of nutrition; and further, his discovery that the starch-grains to be found in chloroplastids are the first visible product of their assimilatory activity. His later papers were published in the three volumes
of the Arbeiten des botanischen Instituts in Wiirzburg (1871— 88). Among these are his investigation of the periodicity of growth in length ; his researches on heliotropism and geotropism, in which he introduced the "clinostat"; his work on the structure and arrangement of cells in growing-points; the evidence upon which he based his "imbibition-theory" of the transpiration-cur rent ; his studies of the assimilatory activity of the green leaf ; and other papers.
Sachs' works are: Handbuch der Experimentalphysiologie der Pflanzen (1865, French edition, 1868) ; Lehrbuch der Botanik (1868, Eng. ed. 1875 and 1882), a comprehensive work, giving a summary of the botanical science of the period, including the results of original investigations; Vorlesungen fiber Pflanzenphysiologie (1st ed., 1882; 2nd ed., 1887; Eng. ed., Oxford, 1887) ; Geschichte der Batanik (1875, Eng. ed. 189o).
A full account of Sach's 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.