Pathfinder is the biography of a ground-breaking English scientist who, like many women, has been neglected by posterity. Harriette Chick began her career at the turn of the twentieth century, when vitamin deficiency diseases—in particular, beri-beri, pellagra and rickets—were major killers and disablers. During her 40-year tenure at the Lister Institute in London she made fundamental discoveries in understanding and preventing these diseases, saving many thousands of lives. She became the first British woman since the eighteenth century to earn a job as a full-time scientist and her accomplishments opened the door for other women. This book describes the life of a Victorian woman working in a man's world and explores the reasons for Harriette Chick's unique success.