His eldest son, Eilhard Ernst Gustav, born at Berlin on the 1st of August 1852, became professor of physics at Erlangen in 1886, and his younger son, Alfred, born at Berlin on the 18th of July 1856, was appointed to the extraordinary professorship of Egyptology at Bonn in 1892.
In December 1691 he was appointed receiver of the tithes which were originally paid to the bishop of Utrecht, and five years later was nominated to the professorship of eloquence and history.
After a few years the father quarrelled with the Russian government, and went to England, where he obtained a professorship of natural history and the modern languages at the famous nonconformist academy at Warrington.
He retired from his professorship in 1876, and died at Konigsberg on the 23rd of May 1895.
In 1868 he obtained the same professorship at Edinburgh University, and in 1873 he published a textbook of Magnetism and Electricity, full of original work.