Theoretical limits of Lavoisiers analytical program

38 On this experimental practice of plant chemistry around 1800, see also Tomic [2003]. 

It had long been assumed by chemists that the properties of a substance depended not only on the qualities of its constituting elements, but also on the proportion of 

41 Kiyohisa Fuji has stated that the law of definite proportions was a truism of the eighteenth-century notion of affinity (see Fujii [1986]). However, this interpretation is contradicted by the fact that eighteenth-century affinity tables also included alloys and solutions. Furthermore, as Kapoor has pointed out, it was a problem for Proust to explain the general vahdity of his law (Kapoor [1965]). For the content of the law of definite proportions, see also Christie [1994]. On the acceptance of the law, see also Mauskopf [1976]. For life and work of Proust, see Gillispie [1970-1980] vol. XI p. 166ff 

In his Philosophie Chimique Fourcroy stated that most of the sixteen immediate materials of plants, which he had clearly discerned as different kinds of materials, agreed in their elemental composition and differed only by the diverse proportions of these elements. If one calculated the number of different compounds resulting from the combinations of different proportions of three or four simple elements, he continued, a very great number of compounds was possible  

In this method we might indicate which of their elements [of vegetable substances] existed in excess, without circumlocution, after the manner used by Rouelle for naming vegetable extracts he calls these extracto-resinous when the extractive matter prevails in their composition, and resino-extractive when they contain a larger proportion of resin- 

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