William Hooker and his son Joseph were famous as botanists and as the creators of the Royal Botanic Gardens in Kew. Joseph was famous also as the friend and mentor of Charles Darwin. But there was another brother, a little older than Joseph, also a doctor and naturalist. He went to Jamaica in the interests of his health and soon died there of yellow fever. His life was short and tragic with a medical conundrum at its end but its story also illustrates many of the beliefs and concerns that preoccupied doctors in this early Victorian era. It also illustrates the close relationship between medicine and botany that prevailed then.