The correspondence of Professor Thomas Stewart Traill includes letters from some of the most distinguished scientists of the day especially in the fields of medicine, natural history, and mineralogy. Traill's wide ranging interests have also resulted in correspondence concerning political matters, the founding of Mechanics Institutes, and his art collection. His applications for the Chairs of materia medica and medical jurisprudence at Edinburgh result in a concentration of correspondence in 1832 and MS.19344 consists of testimonials in Traill's favour.