ABSTRACT
This chapter outlines the development of organic chemistry to 1874, before J. H. Van't Hoff and J. A. Le Bel introduced spatial concepts of the carbon atom. It explores at the principal weaknesses or drawbacks of the structure theory. The theories of organic chemistry served as the scientific basis of a thriving and rapidly growing industry that employed increasing numbers of professionals trained specifically as chemists, and nearly all university chairs of chemistry were occupied by organic chemists who directed large teaching laboratories. Although the unsaturated acids provided the easiest case for establishing the existence of 'absolute' isomers, the difficult chemistry of the isomeric lactic acids would provide the direct inspiration for Van' t Hoff. As the structure theory emerged in the 1850s and 1860s, it contained explicit hypothetico-deductive characteristics, along with the classificatory devices in the tradition of natural history.
