Analysis by fire

In spite of the failure of alchemy to reach its goals of transmutation, there was a positive gain from the fifteen centuries of alchemical practice. The accumulated knowledge of the particular behavior of metals and their compounds was considerable, and the invention of the art of distillation led to the isolation and characterization of alcohol and the inorganic acids. In its broadest application, distillation became the standard method of analysis by fire. ... 

That mineral sulfur contained the acid of sulphur was an unchallenged fact to chymists of that time, a natural conclusion to draw from the application of analysis by fire. Lemery here points out that the acid spirit from mineral sulfur is the same as that obtained from vitriol. 

Firmly in the iatrochemical tradition, Homberg believed that the analysis by fire revealed the familiar five principles, salt, sulphur, mercury, WATER, and EARTH. SuLPHUR was the active and earth the passive principle, the others having an intermediate nature. Earth never acts, but serves only as a receptacle or matrix for the other principles.These, of course, were the philosophical principles, and he spent some time describ-... 

Allen G. Debus, Fire Analysis and the Elements in the Sixteenth and the Seventeenth Centuries, Annals of Science 23, 1967, 127-147 F. L. Holmes, Analysis by Fire and Solvent Extractions The Metamorphosis of a Tradition, Isis 62, 1971, 129-148. 

Holmes, Frederic Lawrence. Analysis by Fire and Solvent Extractions The Metamorphosis of a Tradition. Isis 62, 1971, 129-148. 

My aim in this paper is to examine the case of Herman Boerhaave in order to suggest that the instruments constituted one solution to what many chemists considered to be a fundamental problem in traditional chymical approaches at the turn of the eighteenth century claims about material composition based on analysis by fire. Many seventeenth-century chemists, for example Robert Boyle, began to doubt the efficacy of traditional fire analysis to decompose bodies into their principles or elements without altering the products of the analysis.7 Following the work of Boyle, Boerhaave... 

In the preface to his plant chemistry, Bucquet distinguished between analysis by solvents and analysis by fire. Like his predecessors, he asserted that the analysis by solvents enabled chemists to extract without any alteration the materials which enter into the composition of plants, and which are very compound principles, (Bucquet [1773] vol. 1 p. vi). 

Fired Heater as a Heat-Exchangee System. Improved efficiency in fired heaters has tended to focus on heat lost with the stack gases. When stack temperatures exceed 150°C, such attention is proper, but other losses can be much bigger when viewed from a lost-work perspective. For example, a reformer lost-work analysis by Monsanto gave the breakdown shown in Table 2. 

The tin content of ores, concentrates, ingot metal, and other products is determined by fire assay, fusion method, and volumetric wet analysis. 

When the copper content in the Dorn metal has been reduced to less than 1% by fire refining, the metal is cast into anodes for electrolytic separation of silver. A typical analysis of Dorn metal is... 

Mahoney (1997) has analysed the 170 largest losses in refineries, petrochemical plants and gas processing plants from 1966 to 1996. Nearly all the losses in the analysis involved fires or explosions. Most common primary cause of losses was piping. Instone (1989) analysed some 2000 large loss claims of hydrocarbon industry at Cigna Insurance. Table 20 lists the ISBL equipment and Table 21 lists the data of the OSBL equipment by Mahoney (1992, 1997) and Instone (1989). 

The difficulty in gaining useful compositional knowledge at this early stage was neatly expressed by Paul Walden. In the early days every new compound body represented a new riddle. The only method of analysis available was that by fire, and the products were necessarily assumed to be simpler than the body that had been heated and perhaps to be the actual components of that body. This has been the most naive assumption as we saw presented and argued by Beguin. 

The use of the analysis/synthesis cycle as a way of confirming the qualitative composition of a body becomes a conscious and deliberate method about this time, made possible by the growing knowledge of the composition of neutral salts. If a body analyzed by fire could be reformed from the elements obtained, it would constitute a convincing demonstration of the validity of the analytical results. The reader may recall that Robert Boyle... 

A sample of CBI ceramic aggregate was prepared for elemental analysis by initially evaporating the sample to dryness in a mixture of concentrated hydrofluoric and sulfuric acids. The residue was then dissolved in hydrochloric acid and analyzed by atomic absorption spectrometry. Table 3 presents these results, and corresponding data from TTLC analyses of unfired and fired samples of the same material. 

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