Stanislao Cannizzaro, remembered today largely for the Cannizzaro reaction, had rendered great service to chemistry with his 1858 paper Sunto di un corso di Filosofia chimica, or Sketch of a course of chemical philosophy, in which he had insisted on the distinction, previously hypothesized by Avogadro, between atomic and molecular weights.
Cannizzaro had showed how the atomic weights of elements contained in volatile compounds can be deduced from the molecular weights of those compounds, and how the atomic weights of elements of whose compounds the vapor densities are unknown can be determined from a knowledge of their specific heats.
These achievements are of fundamental importance to atomic theory.
Cannizzaro plays an influential role in the atomic-weight deliberations of the Karlsruhe Congress in 1860.
