After leaving college he began the study of law under the direction of Mr. Story, but very soon abandoned it, and entered the office of his uncle, the late Dr. B. Lynde Oliver, of Salem, as a student of medicine. In 1809, he entered the University of Pennsylvania, at that time distinguished by the names of Rush, Wistar, and Physick, and by his talents and attainments soon attracted the notice of Dr. Rush, whose favorite pupil and warm friend he afterwards became. On receiving his medical degree, the following letter, written in terms of the highest compliment, was addressed by Dr. Rush to his uncle and former instructor.
"Philadelphia, May 1, 1810.
"Dear Sir: I sit down with great pleasure to answer your letter by your nephew, now Dr. Oliver, and to inform you at the same time that he has received the honor of a doctor's degree in our university much to his credit and the satisfaction of his teachers. From his singular talents, and from his acquirements and manners, he cannot fail of becoming eminent in his profession. Long, very long, may he live to reflect honor upon all who are related to him, or who have been instrumental in opening and directing his acute and capacious mind in the prosecution of his studies! Be assured he carries with him my highest respect and sincere affection.
"With respectful compliments to the venerable patriarch of medicine, Dr. Holyoke (if not translated to a better world),
"I am, dear sir, very sincerely yours,
"Benjamin Rush.
"Dr. B. Lynde Oliver."
On his return to Salem, Dr. Oliver commenced the practice of medicine, and in July, 1811, as appears from his diary, he connected himself with Dr. R. D. Mussey, then a rising young surgeon, and with whom he was afterwards so long associated. From the following entry in the diary referred to, under date of July 12, 1812, may be learned somewhat of his tastes at this time, and his mode of passing the waiting hours of an early professional life:
"This day completed the first year of my connection in the medical profession with Dr. R. D. Massey. On reviewing this period, I am sensible of a great loss of time, and of a degree of professional and literary improvement altogether inadequate to such an extent of time. Some improvement, however, has I hope, been made. With respect to the books which I have read during the past year, the most important are Mosheim's 'Ecclesiastical History,' which I have not yet quite completed,—a learned and judicious outline of the history of the church, embracing many collateral topics of learning and philosophy ...; Homer's 'Iliad' in Greek, with the exception of the last book; the 'Æneid' except the last two; two or three books of Livy, and several of Juvenal's 'Satires.'
"The most important literary enterprise which I have undertaken and accomplished has been the delivery of a course of lectures on Chemistry in connection with Dr. Mussey. In Anatomy, also, we have executed something. Medicine will, in future, claim more of my attention, but not to the neglect of the two important collateral branches above mentioned."