Dr. Rock — A most learned and excellent lecture on American slavery was delivered in this place Jan. 3 by John S. Rock, M.D., a colored dentist of Boston. He is a handsome speaker, and his lecture evinced a fine education, superior scholarship, and much careful research, especially with reference to the unity of the race. Let our anti-slavery friends in other towns employ him to lecture in their midst, and patronize him as his office in Boston. — Worcester Spy.
(Liberator, Jan. 26, 1855, pg 3)