a German theologian, son of F.S.G. Sack, was born at Berlin, Oct. 17, 1790. He studied at Gottingen and Berlin, and commenced his lectures at the Berlin University in 1817. In 1818 he was made professor extraordinary, and in 1832 professor of theology in Bonn. He died at Pappelsdorf, near Bonn, Oct. 16, 1875. Of his many works we mention Christliche Apologetik (Hamb. 1841): — Christliche Polemik (ibid. 1838): — Geschichte der Predigt von Mosheim bis Schleiermacher und Menken (Heidelberg, 1866): Theologische Aufsatze (Gotha, 1871, etc.). See Zuchold, Bibliotheca Theologica, 2, 1106 sq.; Theologisches Universal- Lexikon, s.v.; Koch, Gesch. des deutschen Kirchenliedes, 7, 353; Literarischer Handweiser (1875), p. 433; Theologisches Jahrbuch (Bielefeld, 1877), p. 228. (B.P.)