Alexandre Édouard Baudrimont: Crystallography, colloids, aqua regia

Alexander Édouard Baudrimont (1806-1880) was a French physician and pharmacist that carried on fundamental research on a wide variety of subjects, among them, philosophy of science, linguistic, colloidal chemistry, cosmology, crystallography, mechanics of materials, etc. The same as Ampère, he proposed a new theory where only certain geometrical shapes were able to induce a
chemical reaction. When atoms combined to form and integral molecule, they assumed an arrangement that if not regular, was at least symmetric. Chemical formulas did not represent the absolute number of atoms present; they represented only a number proportional to the real one. Crystalline particles were always small polyhedrons, which adapted one to the other without leaving
empty spaces, a condition satisfied only by only cuboids, hexahedral prisms, and dodecahedrons. Baudrimont was one of the pioneers of colloid chemistry; many of the results of his experiments about colloids anticipated in many years those of Graham. He showed that the stability of an artificial emulsion depended on the relation of the amount of water added to that of the glue, and not that of the oil. Organic products enjoying a more o less complex organization, they were always solid or soft, forming spherical or spheroidal particles having diameters varying from 2/100 of a millimeter to about one millimeter. At higher levels the particles arranged themselves under the influence of definite forces, Baudrimont proposed that the gas chloronitric acid as the active compound of aqua regia. Its liquid boiled at -7.2OC. This gas attacked all the metals it came into contact and with pulverulent silver it exploded and disappeared instantly. Its composition, NO3Cl2, was very similar to that of anhydrous nitric
acid.