Description of the Tableau

A first glance at the table (figure 5.1) shows that the classificatory system it renders cannot be grasped immediately. The table is crowded with such an enormous number of names of chemical substances that it takes some time to recognize structures and patterns. The first task is, therefore, to pave a way to such stmctures and patterns. For this purpose, it might be useful to present some diagrams that approach the main structure of the table step by step. 

This reduction is justified by the table. In the cases of the salts (field V/b) and of the metal oxides (field III/c), the authors of the table themselves listed only a selec- 

1 See the literature referred to above in footnote 1 to chapter 4. This collection of secondary literature could easily be extended if we drew in literature on the four authors of the Methode or on the Chemical Revolution in general, which usually addresses more or less elaborately the nomenclatural enterprise of 1787. 

The question of whether the table is complete in the strong sense or in the weak sense must take into account that the authors of the Methode confined themselves to classifying and naming a rather small selection of the chemical substances known at the time. The wealth of substances extracted or distilled from plant or animal materials is almost entirely absent in the table, as is the majority of mineral raw materials known from mines or oryctological collections. In other words, the table does not try to classify and name all substances then known, but only a small part of them. Whether the table can claim a strong or weak classificatory completeness for this selection of substances depends, of course, on the criteria for this selection. 

Since the four authors even did not mention the very fact that names were proposed for only a small selection of chemical substances, let alone argue for the criteria of their selection, these criteria become manifest only in analysis. Since no contemporary complained about this omission, we can conclude that the selection and its criteria must have been obvious to the historical actors. In hindsight, it is clear what was selected the table provides slots only for pure chemical substances, that is, substances that are either simple substances (Lavoisierian elements), or chemical compounds that undergo reversible decompositions and recompositions.  

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