Thomas Jefferson was a devoted amateur scientist, who took great pride in being president of the American Philosophical Society (1797-1815). He administered America's first patent office, although he never patented his own invention of a more efficient plow. Among his other inventions, was a "polygraph" machine with a second pen that automatically copied letters as he wrote them—a handy device, since he wrote forty thousand letters in his lifetime. In 1785 Jefferson published Notes on the State of Virginia Originally conceived as a refutation of a French naturalist's view that nature is "less active, less energetic" in the New- World than in Europe, and that the animals of America are smaller than those of the Old World, Notes on Virginia covers geography, history, climate, religion, laws, and society, as well as his controversial views on slavery. As a promoter of science Jefferson helped popularize smallpox vaccination and...