lxiv PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



Dumont had earned the high character for unwearied zeal and energy 

 in geological research, ascribed to him not merely by his own country- 

 men, but by the geologists of all Europe : some further remarks on 

 his writings are, however, necessary to give a clear idea of his great 

 and varied talents, as well as of that independence of mind which 

 led him perhaps sometimes to an excessive dread of being shackled 

 by systems. The Memoir on the Geological Constitution of the Pro- 

 vince of Liege was his first great work, and gained the prize offered 

 by the Academy of Brussels for the essay which should best fulfil the 

 following conditions : " describe the Geology of the Province of Liege ; 

 point out the mineral species and accidental fossils which are there 

 found, the localities where they occur, and the synonyms of all sub- 

 stances already known and which have been before described." 

 There were two other competitors for this prize ; and the epigraphs 

 attached to the papers of Dumont and of his next ablest opponent, 

 who gained a silver medal, are as follows : that of the second com- 

 petitor was a passage from Baillet to this effect, — " few systems and 

 many facts, ought to be the motto of a Naturalist," a sentiment 

 which well defines the views of Dumont himself, whilst his own 

 epigraph, " the relative age of the primordial rocks cannot be deter- 

 mined with certainty from their inclination," may be taken as the 

 expression of the results of his labours. 



M. Dumont adopts the nomenclature of D'Omalius d'Halloy for 

 "Terrains" or Formations, and that of Alexandre Brongniart for 

 Bocks. The primordial formations of the province of Liege he de- 

 scribes as occurring in basins, the stratification as conformable, and 

 the rocks as divisible into three groups, which, in conformity with 

 the views of D'Omalius, he designates the Schist- or Slate-group, 

 the Anthracitiferous group, and the Coal-group ; the coal-group rest- 

 ing on the anthracitiferous group, and that upon the slate-group. 



Describing his rocks from below upwards, he enumerates in the 

 slate-group : 1. Diallage-slate, consisting of a paste of talc with 

 lamellar diallage disseminated ; 2. Red Slate, consisting also of a tal- 

 cose base, with red grains of (?) peroxide of iron ; this and the preceding 

 belong to the " Steaschiste " of Brongniart; 3. Common Clay-slate ; 

 4. Quartz- and talc-slate ; 5. Granular Quartz ; 6. Talcose Conglome- 

 rate and Puddingstone ; 7. Freestone or Diorite of Brongniart. 



These rocks might be considered as forming parts of one great 

 whole, the varieties being consequent on the accidental presence of 

 certain mineral elements in different parts of the series at the time 

 when crystallization was induced in the mass by metamorphic action ; 

 but M. Dumont divides them into two systems : the Inferior com- 

 prising the Diallage-slate, the Granular Eed Slate, the Talcose Pud- 

 dingstone, and a little Clay- slate ; whilst the upper system principally 

 consists of common Clay- slate and of Granular Quartz, including in 

 some parts Talco-quartz-slate and Greenstone : but this arrange- 

 ment, if invariable, would be quite consistent with the theory of a 

 simultaneous metamorphic change through the whole mass. 



The several rocks which have been named as constituting the Slate- 

 formation are not irregularly distributed, but are arranged in definite 

 order. The whole formation in the province of Liege is divided into 



