The subject of this sketch was born in Salem, N. J., in 1825. When quite a child, he became passionately attached to his book, and, unlike most children, seldom indulged in amusements of any kind. His parents, anxious to make the most of his talents, kept him at school until he was eighteen years of age, at which time he was examined and approved as a teacher of public schools. He taught school from 1844 to 1848. Mr. David Allen writes, "His was certainly the most orderly, and the best conducted, school I ever visited, although myself a teacher for nearly twenty years." During the time Mr. Rock was teaching, Drs. Sharp and Gibbon opened their libraries to him, and he commenced the study of physic,--teaching six hours, studying eight, and giving private lessons two hours every day. After completing his medical studies, he found it impossible to get into a medical college; so he abandoned his idea of becoming a physician, and went with Dr. Harbert and studied dentistry. He finished his studies in the summer of 1849. In January, 1850, he went to Philadelphia to practise his profession. In 1851, he received a silver medal for artificial teeth. In the same year, he took a silver medal for a prize essay on temperance. After the Apprentices' High School had been established in Philadelphia, and while it was still an evening school, Mr. Rock took charge of it, and kept it until it was merged into a day school, under the direction of Professor Reason. He attended lectures in the American Medical College, and graduated in 1852.