CONTENTS. 



Page 



PREFACE iii 



Brononiart^s Classification of the Mixed Rocks ... . tu 



Synoptical Table of Equivalent Formations., by H. T. 

 De la Deche, Esq. F.R.S. Sfc. 



Geological Sketch of the Coal District of Saint- Etienney 

 department of the Loire. By M. Beaunier, 

 Engineer in Chief of the Royal Mining Corps. . . ^ 1 



Memoir on the Geological extent of the Formation of the 



Environs of Paris. By J. J, D'Omalius D'Haleoy 9 



Extract of a Memoir on the possibility of causing fresh- 

 water Moluscce to live in salt-water^, with geologi- 

 cal applications. By M. Beaudant 36 



On Gabbro ( Euphotide of Hauy).^ By M. von Buch. 



Extracted by M. de Bonnard 42 



Memoir on the Mountain of Rock Salt at Cardona, in 



Spain. By M. F. Louis Cordier 52 



Observations on the for/nations of Ancient Gypsum oc- 

 curring in the Alps., particularly on those consi- 

 dered as primitive ; preceded by new facts relative 

 to the transition rocks of that chain. By M. Bro- 

 CHAifT t>E ViLLiERSy Engineer in Chief of the 

 Royal Mining Corps 62 



Geological Sketch of the Thuringerwald. By M. de 



IJoFF, Counsellor of Legation at Gotha 88 



On some basaltic mountains of Hesse and Thuringia. 



By M. DE HOFF ' lOQ 



Report on the Tin of Periac (department of the Loire 

 Inferieure)^ by Messrs. Junker andDuFRENor, 

 Assistants to the Royal Mining Corps 106 



Considerations on the place that the granitic rocks of 

 Mont Blanc and other central summits of the Alps 

 ought to occupy in the order of anteriority of the 

 primitive series. By M. Brochant de Filliers 113 



Memoir on the Geology of the Environs of Lons-le- 



Saunier. By M. Cuarbaut, Engineer of the Mines 127 



