A Missing Chapter in the History of Organic Chemistry: The Link between Elementary Analysis by Dry-Distillation and Combustion

Prior to the introduction of elementary analysis by combustion (i), organic matter was analysed over a period of nearly two hundred years by dry-distillation (2). The results obtained by this method were recorded, where possible, in weighed fractions referred to either as the gaseous part, the phlegma, the oil and the carbon residue, or later on as the carbonic oxide and carbonic acid fractions, the watery fraction, the emphyrematic oil, the acidic fraction, the carburated hydrogen fraction and the charcoal residue. Reference was also made to the volatile alkalies or later on to nitrogen and ammonia. With the introduction of elementary analysis the results came to be expressed either in percentages or in ratios of carbon, hydrogen, oxygen and nitrogen, from which the empirical formulae