The Specialization of the Sciences.

By the 1850s two of every three American scientists were limiting themselves to specific fields, and many were focusing on subfields. In the six major areas—chemistry, mathematics, physics, life sciences, earth sciences, and astronomy —American scientists made notable advances, and some of them acquired worldwide reputations. Yet American science, for the most part, remained less sophisticated than European science. Unlike Europeans, American scientists tended to focus on experimentation, measurement, and description rather than theory, although important exceptions existed.

Chemistry.

In the mid-nineteenth century European chemists made revolutionary discoveries, establishing the atomic theory and the periodic table of the elements and making important advances in organic chemistry. American chemists, far behind the Europeans in theory, applied the new ideas to develop new or better industrial products, such as dyes, explosives, and petroleum derivatives. The economic benefits...