In 1791, he was admitted a student of the arts in Columbia college. Nicholas Romayne, M.D. was at this time among the physicians of highest consideration in New-York, and was engaged in delivering lectures on different subjects of medical science in Columbia College. Having pursued the early part of his medical studies with Dr. William Bruce, he felt a generous gratitude for the instruction and attention which he had received from him, and endeavoured to requite them by advising with his son, and promoting his views, as far as lay in his power. Here commenced a friendship which increased with advancing years, and terminated but with life. At this period, young Bruce began to evince a desire to oppose the inclination of his father and friends by studying medicine; this study, without their knowledge, and while a student of the arts in the senior class, he commenced by attending Dr. Romayne's lectures. Such was the strong bent of his mind towards the study of medicine, and its collateral physical pursuits, that the persuasion and remonstrances of his friends proved alike ineffectual, and he soon gave free scope to the prevailing inclination. The collection and examination of minerals, a pursuit not then at all attended to in this country, was his particular relief from other studies; for even during his recreation, he was ever on the look-out for something new or instructing in mineralogy. Dr. Romayne being about visiting Europe, young Bruce pursued his studies with Samuel Bard, M.D.; and having attended the usual courses in Columbia College, he left the United States for Europe in 1798, and in 1800 he obtained the degree of doctor in medicine from the University of Edinburgh, after defending a Thesis, De Variola Vaccina. Having now finished his medical studies, he was prepared to visit the continent of Europe with peculiar advantage; for his continued attachment to mineralogy, a liberal distribution of American specimens then comparatively new in Europe, and his social habits and dispositions, which were very conciliating, secured him the best introductions from Edinburgh, and laid the foundation of permanent friendships. During a tour of two years, he visited France, Switzerland, and Italy; and collected a mineralogical cabinet of great value and extent. After his return to England, he married in London, and came out to New-York in the autumn of 1803, to enter on the active duties of a practitioner of medicine.