The origin and early years of any rapidly changing scientific discipline runs the risk of being forgotten unless a record of its past is preserved. In this, the first book-length history of clinical chemistry, those involved or interested in the field will read about who and what went before them and how the profession came to its present state of clinical importance. The narrative reconstructs the origins of clinical chemistry in the seventeenth century and traces its often obscure path of development in the shadow of organic chemistry, physiology and biochemistry until it assumes its own identity at the beginning of the twentieth century. The chronological development of the story reveals the varied roots from which modern clinical chemistry arose.