Daniel Turner’s prolific writings provide valuable insight into the practice of a commonplace Enlightenment London surgeon. Examining his personal, professional, and genteel achievements. Enhances our understanding of the boundary between surgeons and physicians in Enlightenment ‘marketplace’ practice. Turner’s pioneering writing on skin disease, De Morbis Cutaneis, emphasizes the skin’s role as a physical and professional boundary between university-educated physicians who treated internal disease and apprentice-trained surgeons relegated to the care of external disorders. Turner’s career-long crusade against quackery and his voluminous writings on syphilis, a common ‘surgical disorder’, provide a refined view into distinction between orthodox and quack practices in eighteenth-century London.