William Osler's address, The Reserves of Life, was given to students at St Mary's Hospital Medical School in London in 1907. In the talk Osler likened a medical career to a race through London, pointing out that to be successful one had to have sufficient 'reserves' or staying powers. He also commented on several of his favourite topics and included some of his most memorable aphorisms. Almroth Wright was the colourful and controversial physician at St Mary's Hospital who described opsonins and was a strong advocate of vaccine therapy for bacterial infections. Wright was often critical of clinicians and scoffed at their crude methods. During the address to the St Mary's students, Osler abruptly departed from his theme to criticize Wright ('that Celtic Siren') and defend clinicians, emphasizing that the art and science of medicine were inseparable. Despite their differences, Osler and Wright maintained a cordial relationship.