‎MALLARD (E.)‎
‎Explication des phénomènes optiques anomaux que présentent un grand nombre de substances cristallisées ---- EDITION ORIGINALE ---- TIRE-A-PART (OFPRINT) des Annales des mines tome X (1876)‎

‎P., Dunod, 1877, un volume in 8 broché, couverture imprimée, (quelques rousseurs), 141pp., 3 PLANCHES dépliantes‎

Reference : 7490

‎---- EDITION ORIGINALE ---- TIRE-A-PART (OFPRINT) des Annales des mines tome X (1876) ---- "A key figure in the french school of crystallography and a bridge from Bravais to Friedel, Mallard was described as having definitively displaced the center of gravity of crystallography that, thereafter, could not be cultivated as a descriptive science but was elevated to the rank of a rational science. Mallard's contributions in crystallography began in 1876, not long after he had assumed the chair of mineralogy at Paris, He took as his starting point the Etudes cristallographiques of Auguste Bravais. While Sohncke and later A. Schönfiles were developing Bravais's concept of a lattice of translationally equivalent pionts into a complete mathematical description of symmetry of crystals, Mallard independently developed other aspects of Bravais's theories. This work had its notable beginning the memoire Explication des phénomènes optiques anomaux, on optically anomalous crystals, in which the powerful new polarizing microscope showed the importance of twinning in these crystalline edifices and of pseudosymettry as an explanatory concept...". (DSB IX pp. 58/60)**7490/A4‎