No fewer than 345 passages in the Digest are taken from his writings.
His special interest in legislation for the working classes led him to be placed upon the Trades Union Commission of 1867-1869; he was secretary to the commission for the digest of the law, 1869-1870; and was from 1877 to 1889 professor of jurisprudence and international law under the council of legal education.
Danforth (1902-1903); Book Review Digest (1906), &c.; H.
For a digest of some of these see Digest of City Charters, together with other Statutory and Constitutional Provisions relating to Cities, prepared for the Chicago Charter Convention by A.
Vitae (Leipzig, 1862), and there is an important digest of his bulls and official acts in Jaffe-Wattenbach, Regesta pontif.