Meyer, Johann Friedrich

Plate 37. Johann Friedrich von Meyer, extract from unpublished manuscript Cabala magica et theosophica, circa 1805 (Erlangen, Theologische Fakultat, Institut fiir Historische Theologie). Document kindly furnished by Jacques Fabry. 

In vino veritas ( there is truth in wine ) implies that, suitably lubricated, a person may be more likely to confess all. However, the German apothecary Johann Friedrich Meyer (1705-1765) might well have said In colds veritas ( there is truth in chalk ) since it is through calcium carbonate (chalk limestone) that he discovered his acidum pingue—said to be the general principle innate in all bodies, the principle in fire, and the component of all acids (see Figure 178). And... 

FIGURE 178. A table from Johann Friedrich Meyer s 1766 Essais de Chymie. He believed in an acidum pingue ( fatty or oily acid) present in strong ( caustic ) alkali (e.g., KOH) and absent in mild alkali (e.g., K2CO3). Addition of acidum pingue actually corresponded to loss of CO2 much as the addition of phlogiston corresponded to the loss of another invisible gas—oxygen. 

Black s theory was opposed by Johann Friedrich Meyer (Osnabriick 24 October 1705-10 November 1765), an apothecary in Osnabriick, in a book with a characteristic title ... 

The other half-metal referred to in the preceding letter was hydro-siderum, a false element which Apothecary Johann Karl Friedrich Meyer of Stettin, Scheele, and M. H. Klaproth later proved to be a phosphate of iron (73, 74, 41). In another of his letters to Hjelm Scheele said, As far as I can judge of your work, it does you all credit (9). Although this correspondence shows that Hjelm must have isolated molybdenum as early as the fall of 1781, his first paper on it was not published until much later. 

Johann Carl Friedrich Meyer (Stettin 1733-20 February 1811), Court Apothecary in Stettin, besides his papers on colloidal silica (see p. 188), hydrofluoric acid (see p. 215), the non-convertibility of silica into alumina (see p. 568), and the preparation of sodium carbonate from common salt (see p. 562), investigated the solubility of lead in sulphuric acid and the action of acids on strontia, and analysed minerals. He prepared artificial Seltzer water. He found that Siberian native iron dissolves in dilute sulphuric acid to a green solution, which becomes blue with ammonium chloride. Proust later showed that native (Peruvian) and meteoric iron contain nickel. Meyer s supposed new metal, hydrosiderum, he showed himself was iron phosphide (seep. 194). 

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