The Karlsruhe Congress and its Aftermath

Abstract

Soon after the publication in 1858 of his classic paper on the tetravalent carbon atom, Kekulé started work on his textbook entitled Lehrbuch der organischen Chemie. Organic chemistry had made considerable progress in recent years, but was suffering from the confusion that had been rife ever since the chemical atomic theory had been proposed by Dalton. Atomic weights could not be determined from equivalent or combining weights without a knowledge of the formulae of a few simple compounds. Lack of certainty over atomic weights led to uncertainty in the formulae of all other compounds. Many chemists had turned to equivalent weights instead, and indeed there was confusion over the precise meaning of the terms atom, molecule and equivalent. Gerhardt had suggested a system of atomic weights which was substantially correct, but had not won general acceptance. When Kekulé’s book appeared, he quoted nineteen different formulae that had been suggested for acetic acid.