De Saint-Gilles

Since the pioneering work of Berthelot and Pean de Saint-Gilles in 1862, it has been well known that solvents strongly influence both reaction rates and the posi-... 

M. Berthelot and L. Pean de Saint-Gilles, Chim. Phys. 68, 225 (1863). 

The reaction studied was the quatemarization of triethylamine by ethyl iodide at 100 °C [N. Menschutkin, Z. Phys. Chem., 6, 41 (1890)]. Menschutkin s first discussion on solvent effects dealt with the reactions between acetic anhydride and alcohols [Z. Pl s. Chem., 1,611 (1887)]. The catalytic role of solvents was already recognized in 1862 by Berthelot and Pean de Saint Gilles in their Recherches sur les Aflinit6s [see, e. g., H. G. Grimm, H. Ruf, and Wolff, Z. Phys. Chem., B13,301 (1931)]. 

Ann. Chim.y 1862, Ixv, 385 1862, Ixvi, 5, no 1863, Ixviii, 225 see also Berthelot and Saint-Martin, z6., 1872, xxvi, 433 Swarts, Bull. Soc. Chim. Belg., 1928, xxxvii, LIX. L6on P an de Saint-Gilles (Paris 4 January 1832-22 March 1863), a wealthy man who had a private laboratory PoggendorfT, (i), hi, loio. 

Graham used the dialyser to separate colloids, which dialysed slowly, from crystalloids which dialysed rapidly. He prepared colloidal silicic acid, alumina (discovered by Crum)," ferric oxide (including the meta -form described by Pean de Saint-Gilles), etc. He thought colloids could be freed completely from crystalloids by dialysis, but probably traces of crystalloids remain. He says ... 

In most of cases nevertheless the origin of that example is not cited. It comes from a series of experiments done by a couple of Parisian chemists arotmd the 1860 Pierre Eugene MarceUn Berthelot (1827-1907) and Leon Peon de Saint-Gilles (1832-1863), the first one full professor of chemistry at the Ecole de Pharmacie, the second a wealthy dilettante. 

Wilhelmy s work remained largely unnoticed until Ostwald drew attention to it over 30 years later. In the meantime, three pairs of workers had performed important work on reaction kinetics and chemical equilibria. They were the Frenchmen Berthelot and Leon Pean de Saint-Gilles (1832-1863), the Norwegians Cato Maximilian Guldberg (1836-1902) and Peter Waage (1833-1900), and the Englishmen Augustus Vernon Harcourt (1834-1919) and William Esson (1839-1916). 

In 1862, the French chemists Pierre Berthelot and Leon de Saint-Gilles reported on the reaction between ethanol and acetic acid to ethyl acetate and water. They found that the rate of product formation was proportional to the product of the reactant concentrations. In the same years, the Norwegian chemist Waage and the mathematician Guldberg formulated their law of mass action, which, in hindsight, was based on invalid kinetic procedures, although the result was correct. 

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