[2] 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.

Among these are his investigation of the periodicity of growth in length, in connection with which he devised the self-registering auxanometer, by which he established the retarding influence of the highly refrangible rays of the spectrum 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; and other papers of interest.

[4] 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.

[4] The third edition was translated into French by Philippe Édouard Léon Van Tieghem in 1873, and into English by Alfred Bennett in 1875, and published by Oxford University Press.

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.

[4] 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.

[7][8] 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, Karl Prantl, Christian Ernst Stahl, Hugo de Vries and Harry Marshall Ward became later famous botanists.

This so-called Sachs' quantity and quality principle and Knop's four-salt mixture contributed significantly to the development of the famous Hoagland solution.