Humphry Davy grew up poor, helping his mother pay off debts left by his father, a woodcarver who had lost his earnings in speculative investments. As a result, Davy's education was haphazard, and he disliked being a student. The schools in his part of the country (Cornwall, the southwest tip of England) were far from outstanding at that time; still, Davy managed to absorb knowledge of classic literature and science. In later life, he said that he was happy he didn't have to study too hard in school so that he had more time to think on his own. Without money for further education, Davy began at age seventeen to serve as an apprentice to a pharmacist/surgeon. During this time, he took it upon himself to learn more about whatever interested him, such as geography, languages, and philosophy, as well as science. When he was nineteen, Davy...