Atlantic Monthly in 1860, and most of his contributions to literature have been in the form of papers first published in the magazines, and afterwards collected into books. He more than once paid tribute to his teachers in literature. His first book, now out of print, was Notes on Walt Whitman, as Poet and Person, published in 1867; and Whitman: A Study, which appeared in 1896, is a more extended treatment of the man and his poetry and philosophy. Birds and Poets, too, contains a paper on Whitman, entitled The Flight of the Eagle, besides an essay on Emerson, whom he also treated incidentally in his paper, Matthew Arnold on Emerson and Carlyle, in Indoor Studies; and the latter volume contains his essay on Thoreau.
In the autumn of 1863 he went to Washington, and in the following January entered the Treasury Department. He was for some years an assistant in the office of the Comptroller of the Currency, and later chief of the organization division of that Bureau. For some time he was keeper of one of t