v J.J. UOmalius d! H alloy 221 



composed that remarkable series of eloges in which so 

 much of the personal history of the more distinguished 

 men of science of his time is enshrined. Eloquent and 

 picturesque, full of knowledge and sympathy, these bio- 

 graphical notices form a series of the most instructive 

 and delightful essays in the whole range of scientific 

 literature. They include sketches of the life and work of 

 De Saussure, Pallas, Werner, Desmarest, Sir Joseph Banks, 

 Haiiy, and Lamarck. 



Five years after the appearance of the earliest conjoint 

 memoir by Cuvier and Brongniart, the structure of the 

 country which they described was still further explored 

 and elucidated by a man who afterwards rose to fill a 

 leading place among the geologists of Europe J. J. 

 D'Omalius d'Halloy. In 1813 this able observer read to 

 the Institute a memoir on the geology of the Paris basin 

 and the surrounding regions. 1 It corrected and extended 

 the work of his predecessors among the Tertiary forma- 

 tions, but its interest for our present purpose centres 

 mainly in its important contribution to the stratigraphy 

 of the Secondary rocks. He recognized the leading sub- 

 divisions of the Cretaceous series, and actually showed 

 the extent of the system upon a map. He likewise 

 ascertained the stratigraphical relations and range of the 

 Jurassic system, which he called the " old horizontal lime- 

 stone," and which he correctly depicted in its course 

 outside the Chalk. His little map, with its clear outlines 

 and colours, is of historical importance as being the first 

 attempt to construct a true geological map of a large tract 

 of France. It was not a mere chart of the surface rocks, 



1 Ann. des Mines, i. (1817), p. 251. 



