The Quality of Mercy is the biography of two individuals who touched the lives of millions of people. The setting is the second half of the nineteenth and first quarter of the twentieth century. James Cantlie was a doctor, surgeon, founder of civilian first aid and specialist in tropical diseases. He also saved the life of Sun Yat-Sen, First President of China, after Sun was kidnapped in London. Mabel Cantlie supported the tireless activities of her husband but she was also very active in her own right. Mabel’s stability and poise complements the energetic style of her husband. This book gives a vivid history of the period and recreates the hopes of a generation and their faith in progress and sense of purpose. Most noteworthy, it captures James and Mabel Cantlie’s ethic of working selflessly for others. The book covers James Cantlie’s work for the growth of public health institutions and new hospitals. It describes in detail the start of first aid in the mines and streets of Britain. Also, the rise of the Voluntary Aid Societies and the raising by Cantlie of the Volunteer Medical Staff Corps – now Royal Army Medical Corp (Volunteers). All are portrayed in lively and human style. The last chapters describe the agonising clash between democracy and autocracy in the First World War. In addition, the book recaptures the atmosphere of old Hong Kong in a fitting background to the story of tropical medicine. Sir James founded the Royal Society of Tropical Medicine and many facts are told here for the first time. This book gives a sympathetic portrayal of Sun Yat-Sen, the great Chinese leader. Sun was one of Sir James’ first medical students in Hong Kong and one of the first Western trained Chinese doctors. Sun and Sir James became lifelong friends. The account of Sun’s rescue by Cantlie from imprisonment in the Chinese Legation in London reads like a modern detective story. The book makes an original contribution to the history of China from 1887 to 1918. It relates the relevance of these years in Asia to the development of the world.