 Upon the death of Isaac Mayer Wise March 26, 1900, he became president of this institution, and held this position until his death.Mielziner was not a voluminous writer.Apart from several sermons which he published, the first of which was delivered in Waren, 1854, he wrote "Die Verhältnisse der Sklaven bei den Hebräern", Copenhagen, 1859, this being the thesis for which he received the degree of Ph.D. from the University of Giessen.