This inspiring series on "Scientists of the World" has been specially planned for children. Young readers will find that science is fascinating and that it has made the world a far better place to live in A special feature of the series is that it highlights each scientists childhood. Young readers will see quite vividly that the great scientists had once been children like themselves and that if their natural curiosity as children can be combined with perseverance, they may also be able to achieve what these people did. Like Alexander, brought up on a farm, walked four miles to school every day. It was a hard life. An unexpected legacy enabled him to study medicine. Hard work and curiosity led him to an important discovery. What was it?