312 Account of the Proceedings of the 



of France contains the observations of those present at the different 

 meetings upon the papers read before them, and that among them 

 there are remarks of great value, both as respects the memoirs be- 

 fore the Society, and points of geological interest and importance 

 connected with them. Indeed many a i-emark, as in the discussions 

 upon papers read before us, may be considered as the foundation for 

 subsequent researches and discoveries. This year the members of 

 the Geological Society of Fi-ance have had presented to them the 

 first part of a History of the Progress of Geology, from 1834 to 

 1845, by the Vicomte d'Archiac, a closely-printed octavo volume of 

 679 pages, published under the auspices of the French Minister of 

 Public Instruction, M. de Salvandy. This part contains Cosmogonie 

 and Geogenie, the Physique du Globe, Geographie physique and 

 Terrain moderne. 



Geological Society of Ireland. — Our sister society in Dublin 

 has, as heretofore, been active in promoting the advance of our 

 science in Ii-eland. The earliest communication made to it during 

 the year was by Sir Robert Kane, on the occurrence, in the county 

 Clare, of carbonate of manganese as a thin earthy bed, interposed 

 between a decomposed surface of old red sandstone and a bog, two 

 feet deep. To all appearance this carbonate of manganese is of com- 

 paratively recent origin. Respecting mineral substances a valuable 

 paper was read by Dr Apjohn upon an undescribed variety of hyalite 

 from Mexico, where it is found in large, glossy, transparent, globu- 

 lar concretions. It is considered a hydrate of silica, containing 

 about 2-5 of water, and was found by the optical researches of Dr 

 Apjohn to be formed of a confused aggregation of microscopically- 

 miimte rock-crystals. This result will be appreciated by those ac- 

 quainted with hyalite, a mineral exhibiting, at first sight, few traces 

 of crystalline ai-rangomcnt ; and it at the same time proves the value 

 of optical methods of research in the examination of minerals. 



Another communication of interest respecting mineral substances 

 was made by Professor Oldham. Among the many alterations in 

 the structure of the various beds of the older fossiliferous rocks of 

 the counties Wicklow and Wexford, caused by the protrusion through 

 them of the granites, is one wherein the component parts of the beds 

 have been so acted upon, that crystals of andalusite are abundantly 

 formed amid micaceous slates, themselves altered argillaceous slates. 

 The crystals of this mineral, sometimes of large size, occur in mul- 

 titudes, crossing each other in all directions. Among these, Profes- 

 sor Oldham discovered some which had themselves been again re- 

 placed by mica, the latter occupying the space once filled by the 

 matter of the andalusite, and its cleavage planes usually running 

 across the principal axis of the original crystal, though sometimes 

 occurring' in planes perpendicular to every surface of it. This Aove- 



