Jean Baptiste Julien d'Omalius d'Halloy

Jean Baptiste Julien d'Omalius d'Halloy (17 February 1783 in Liège – 15 January 1875 in Brussels) was a Belgian statesman and geologist.

His daughter Sophie married on February 27, 1838 Baron Edmond de Selys Longchamps, vice-president of the Senate of Belgium, renowned entomologist, president of the Royal Society of Sciences of Liège.

After completing his classical studies in his home town he was sent to Paris in 1801 by his parents to avail himself of the social and literary advantages of the metropolis.

A lively interest, however, in geology awakened by the works of Buffon, directed his steps to the museums and the Jardin des Plantes.

[1] He devoted himself energetically to the work and by 1813 had traversed over 15,500 miles across France, Belgium, the Netherlands and portions of Germany, Switzerland and Italy.

The map which he had made of France and the neighbouring territories was not published until 1822 and served as a basis for the more detailed surveys of Armand Dufrénoy and Elie de Beaumont.

He insisted on the harmony between faith and science, making this the subject of his oration on the occasion of the golden jubilee of the Belgian Academy in 1866.

He studied also in detail the Tertiary deposits of the Paris Basin, and ascertained the extent of the Cretaceous and some of the older strata, which he for the first time clearly depicted on a map (1817).

In his book Des Races humaines ou Eléments d'Ethnographie, Halloy established a racial classification according to skin colour.

As a statesman Halloy had at heart the well-being of the people and, though his duties allowed him little opportunity for extended geological research, he retained a lively interest in his favourite science and engaged occasionally in field work.