(Born: Chateauneuf-sur-Cher, France, 4 February 1833; Died: Paris, France, 6 July 1894) French mineralogist & mine engineer.

From 1872 to 1894, Mallard was professor of mineralogy at the École des Mines in Paris. In 1890, he was elected to the Academie des Sciences in Paris. Mallard researched crystallography and isomorphism. His investigations into gas and mine explosions helped provide safer conditions for miners. He participated in the geological mapping of France.

Biographical references: ABF: I 695, 338-339. • Annales des Mines: 9th series, 7 (1895), 267-303 [by A. de Lapparent]. • Barr, Index to Biographical Fragments, 1973: 166. • Bulletin de la Société Française de Minéralogie: 7 (1894), 241-66, portrait [by G. Wyrouboff]. • Bulletin de la Société Géologique de France: 23 (1895), 179-91. • DSB: 9, 58-60 [by W.T. Hosler]. • Lacroix, Figures des Savants, 1932-8: 1, 69-79, plates 13-14. • Lambrecht & Quenstedt, Catalogus, 1938: 277. • Mémoire Academie Sci. Institute Francais: 60 (1931), p. I-LXXVI [by A. Lacroix]. • Mineralogical Magazine: 7 (1887), no. 48, 328-30 [by G. Wyrouboff]. • Poggendorff: 3, 1641 & 4, 948. • Sarjeant, Geologists, 1980: 3, 1641. • WBI. • World Who's Who in Science: 1100.

Traité de Cristallographie, 1879

1. French, 1879-84 [First edition].
Traité | De | Cristallographie | Géométrique Et Physique | Par | M. Ernest Mallard | Ingénieur en chef des mines, professeur à l'École des mines | [short rule] | Tome Premier | [short rule] | Atlas | [short rule] | Paris | Dunod, Éditeur | Libraire Des Corps Des Ponts Et Chaussées Et Des Mines | Quai Des Augustins, N° 42 | [short rule] | 1879.

[Vol 1: 1879] 8°: [4], [i]-vi, [1]-372 p. [Vol 2: 1884] 8°: [i]-vi, [1]-599, [1] p., 8 chromolithographic plates. [Atlas] 4°: ?? p.

Contents: [Vol 1] [2 pgs], Half title page, "Traité | De | Cristallographie," verso "...Typographie A. Lahure..."; [2 pgs], Title page, verso blank.; [i]-vi, "Préface."; [1]-363, Text.; [364], Blank.; [365]-366, "Explication Des Planches."; [367]-370, "Table Des Matières."; [371]-372, "Errata."

[Vol 2] [i-ii], Half title page, "Traité | De | Cristallographie," verso "...Typographie A. Lahure..."; [iii-iv], Title page, verso blank.; [v]-vi, "Préface | Du Second Volume."; [1]-587, Text.; [588], Blank.; [589]-599, "Table Des Matières."; [1 pg], "Errata Du Premier Volume."; [At end], 8 chromolithographic plates.

Rare. In his Traité de Cristallographie Mallard presents the subject with clarity, and describes the geometrical and physical properties of crystals and proposes a classification system. Taking as his starting point the researches of Auguste Bravais, Mallard studied those crystals that appeared to have greater symmetry than their optical properties would indicate and which the important new polarizing microscope showed the importance of twinning in these "crystalline edifices." He introduced the concept of a pseudosymmetry as an explanation of such crystals. He summarized his ideas in the Traité de Cristallographie that began to appear in 1879. The first volume described geometrical crystallography, lattice theory, and crystal morphology. In 1884 the second volume was published and it described crystal physics. In this work, for the first time, the difficult mathematical concepts introduced by Bravais to lattice theory were reduced to a comfortable and understandable clarity for nonspecialists. Unfortunately, a planned third volume that was to cover isomorphism, polymorphism, twinning, pseudosymmetry, and crystal growth, was never completed, although individual articles especially with respect to twins were published separately. In all his work, Mallard developed and extended Bravais' lattice theory, especially with respect to the importance of crystal faces and twins.

Bibliographical references: BL [no copy listed]. • Dana's 7th (Bibliography): 76. • Groth, Entwicklungsgeschichte, 1926: 112, 117 & 181-2.

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