Grassmann, Hermann (Günther)
Mathematician and philologist, born in Stettin, Germany. He studied at Berlin, and spent most of his life as a teacher there and in Stettin. His book Die lineale Ausdehnungslehre (1844, The Theory of Linear Extension) developed a general calculus for vectors. It made little impact during his life,and it is only since his death that its importance has gradually been recognized; it anticipated much later work in quaternions, vectors, tensors, matrices, and differential forms. From 1849 he studied Sanskrit and other ancient Indo-European languages and, unlike his mathematics, his work in Indo-European and Germanic philology met with immediate acceptance.