Separation of the ultimate chemical principles

1 See also chapter 2, in which we relate these inquiries to experimental history, technological improvement, and experimental philosophy.  

Seventeenth- and early eighteenth-century chemists beheved that all natural bodies—plants, animals, and minerals—consisted of more or less the same kinds of simple ultimate principles. In the seventeenth century, French chemists such as Etierme de Clave, Nicaise Le Febvre, Christopher Glaser, and Nicolas Lemery proposed five elemental constituents or principles of natural bodies, namely water or pMegma, an acid spirit or mercury, an inflammable sulfur or oil, a fixed salt, and an earth. By dry distillation most plants yielded water, a volatile acid, and a volatile oil, as well as a fixed alkaline salt and a fixed earth, both remaining in the retort. The majority of late seventeenth- and early eighteenth-century chemists considered these five materials to be manifestations of the ultimate chemical principles that is, almost pure principles. Hence, plants played an important role for the corroboration of the French chemical philosophy of five principles they were taken as representatives of all natural bod- 

As with any other theoretical concept, the concept of ultimate chemical principles was defined not only by its reference to chemical operations and to substances that can be observed in the laboratory, but also by its relation to other concepts. In the seventeenth and early eighteenth centuries, the concept of ultimate principles was loaded with meaning going back to alchemical philosophy. As we have shown in chapter 2, in seventeenth-century alchemy and chymistry principles were not quotidian perceptible substances. Rather, they were defined as semina invested with a set of qualities that generated perceptible substances in co-action with the elemental matrix. In most seventeenth-century chymical philosophies—especially those not 

4 For life and work of Dodart and Perrault, see ibid. vol. IV p. 135f. and voL X p. 519ff, respectively. 

5 See Dodart [1731] pp. 153-161. In his considerations on the goal of the chemical analysis of plants, Dodart repeatedly stated that the goal was not the separation of simplest or first principles but rather the separation of principes prochains. The effects of plants often depend on the union of principles, he added (ibid. p. 157f.). He also pointed out that the more compound parts that carry the virtues of plants may be altered by fire, and he proposed to also use extractions by solvents as a means of chemical analysis. On the controversy about methods of chemical analysis among the participants of the Academy s project, see Stroup [1990] pp. 89-102. 

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