GRASSMANN, gras'mith, HERMANN Gels TIIER (1809-71). A German mathematician and Sanskrit scholar, born at Stettin. He was a son of Justus Gunther Grassmann (died 1852 at Stettin), who was well known for his work in crystallography. The young Grassmann devoted his attention at first to and philosophy. which he began studying in Berlin in 1827. He then turned his energies to mathematics, which he taught successively at the industrial school in Berlin, at the Ottoschule in Stettin, and at the Stettin Gymnasium. He is known chiefly for his work Die Wissensehaft der extensirenGrossen oder die Ausdehnungslehre (1844, and later edi tions). The obscure style of this treatise was such as to cause the first edition to pass prac tically unnoticed, and it was not until the theory of quaternions (q.v.) began to be recognized that Grassmann's allied theory attracted attention. In later life he took up the study of Sanskrit, and published a Worterbueh zum Rig Veda (Leip zig, 1875), which is a remarkable example of a combined dictionary and concordance, and is still indispensable to all Sanskrit scholars, and an Uebersetzung des Rig Veda (2 vols., 1876-77),
which is based on the principles of the so-called linguistic school of Vedic interpretation, and is likewise a work of much value. Grassmann was also the discoverer of one of the most important laws of comparative linguistics, which is still known as Grassmann's law (q.v.). His other works include the following: "Neue Theorie der Elektrodynamik" (Poggendortrs Annolen, vol. 64) ; "Theorie der Farbenmischung" (same jour nal, vol. 89; Geometrisehe Analyse, gekniipf I an die von Leibniz erfundene geometrisehe Charak teristik (1847); Lehrhuch der Arithmetik Trigonometric (1861 -641) . A collection of his works on mathematics and physics was published at Leipzig in 1894. Consult Schlegel, H. Gross mann, sein Lehrn and seine Werke (Leipzig, 1878).