Why have we waited so long for a biography of Haldane? He was an intrepid investigator of mine disasters during the late Victorian period, and his work not only saved lives, but advanced knowledge of the way our bodies work. He pinpointed the way in which carbon monoxide acts as such a virulent poison, by combining with haemoglobin of the blood much more actively than oxygen, so depriving the body of its vital support. It was he who introduced the canary as an indicator of the deadly gas, simply because the small bird reacts so much more quickly that it gives warning of a problem in the air. Haldane also warned of the problem of breathing silica dust, leading to the disease of silicosis, which killed many miners and quarry workers. His research was ground breaking, and life saving. Indeed, it was said of him that he had saved more lives than the rest of the medical profession put together. He received little recognition from his academic peers, except towards the end of his long life, but much recognition from the miners. His methods of research, usually using himself as a guinea pig for experimentation remain an inspiration to all medical researchers. Martin Goodman should be praised for his excellent book on the life of John Haldane, both for describing his scientific achievements and his vibrant personal life.