College where he met Dr. John Collins Warren (q. v.), and became the warm friend of John Pickering of Salem, the son of Timothy, Secretary of State under Washington, later a remarkable scholar and jurist. He graduated from College in 1796 at the age of nineteen, and taught for two quarters in Leicester Academy, where he would have stayed longer but for a call from his father, the Supervisor of Internal Revenue for the District of Massachusetts, to take a place as clerk in his office. His fixed purpose, however, was to study medicine, and even to borrow money to carry out his plan.
The young Medical Institution of Harvard University (founded 1783) was still grappling with its problems when Jackson attended its courses in 1796. There were no clinical advantages and the teaching was supplemented by an association with some practitioner outside called a preceptor. The small faculty was a good one for its day; there were Benjamin Waterhouse (q. v.), professor of the theory and practise of physic, John Warren (q. v.), Aaron Dexter (q. v.) and J. Gorman (q. v.), professors of anatomy, physiology, chemistry and materia medica respectively.
Whatever wisdom Jackson got from this institution, his enrollment was important from the fact that it brought him into closer connection with the Warren family, and with Dr. John Collins Warren, who graduated from Harvard in the class next below his, as well as with the Warrens' father, John Warren, (q. v.), the fine, public-spirited patriot of the Revolutionary War, the teacher of human anatomy in the "Medical Institution."
Jackson's first step in his medical education was his enrollment in December, 1797, as a pupil of Dr. E. A. Holyoke (q. v.) of Salem, son of President Holyoke of Harvard College. This remarkable teacher (centenarian) was then the foremost physician in New England; Dr. Jackson ever called him his "glorious old master," who instilled into him accuracy of observation and moderation in treatment. To him he dedicated his graduation thesis on the "Brunonian System" (1809).
The substitution of experience for theory, now a commonplace, was new in those days, and Dr. Jackson's acceptance of this guiding principle enabled him to welcome cordially and critically the methods of clinical research to which Louis, his son's instructor a quarter of a century later, gave so powerful an impulse.
The joint lives of Dr. Holyoke and Dr. Jackson, stretched from 1728 to 1867, over nearly a century and a half, and witnessed a revolution in medical standards, hopes, and aims,—even the transition from superstitution to substantial achievement.
Jackson spent part of a year in England towards the close of his medical studies where John Hunter, Abernethy and Astley Cooper were leaders. Jenner's discovery of the protecting value of vaccine took definite form while he was abroad, and although Jackson was not the first to herald this discovery in America, yet he was active in spreading the knowledge and use of the new method in New England.
In 1799 Jackson received a free passage to London in a ship with his brother Henry as captain. While in London he was a "dresser" at St. Thomas's, and studied anatomy with Cline at that hospital, and with Astley Cooper at Guy's, and vaccination at the St. Pancras Hospital under Woodville, besides attending the regular medical lectures. St. Saviour's Church yard, where he had his rooms, was only a block removed from the Hospital, then near the south end of the old London Bridge. Guy's Hospital nearby was opened for patients in 1725; and from 1768 until 1825 the two institutions were closely united for teaching as the "United Hospitals," and students were at liberty to attend operations and lectures in both.
In August, 1800, he sailed for Boston in the Superb, "a large ship for that period," and reached home in forty-nine days. Two days later he began practice, depending for his first success on vaccination coming into vogue. In his "Reminiscenses," published in old age, he writes:—
"On Oct. 1, 1800, I began business. Vaccination had been introduced about the time that I commenced my studies, but the practice had not been extensively adopted at that day, even in England. Dr. Woodville of London was physician of the Pancras Smallpox and Inoculation Hospital, where he had attended to the subject of vaccination more carefully and more extensively than any other, not exceptting Dr. Jenner. I placed myself under his care (for ten guineas, I believe), and learned all then known about that business. The practice of vaccination had just been introduced here, and Boston was full of it—so far as talking went.
"My friends took me up on that account, so that in that October I derived $150 from that source. I also derived just as much from other business, that made my fees amount to $300 the first month.
"In the remaining 11 months of my first year I earned $500, or nearly $50 a month, or $800 for the year. I must say that everybody talked
