XCVl PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



our body we have this day had to record, who said, " Give me a sub- 

 stance containing sulphur, — admit the presence of the vapours of sul- 

 phur, or sulphurous or sulph-hydrous vapours, — let limestone be also 

 present, and water on the surface or in the atmosphere, and we shall 

 readily have gypsum." M. Frapolli adopts sulphurous acid as the 

 j)rincipal agent of gyiisification, and supposes that, evolved from be- 

 neath, it acted on the edges of recently fractured beds of limestone, 

 replacing the carbonic acid of the latter, the sulphurous being con- 

 verted into sulphuric acid under such a pressure that a portion of the 

 oxygen of the carbonic was appropriated by the sulphurous acid, the 

 remainder escaping as oxide of carbon. 



The gypsum of the zechstein, regularly interstratified in lenticular 

 masses with limestones and dolomite, is not thought to have been 

 formed in the manner above noticed, but by the wet way {la vote 

 huniide), sulphurous acid gas being evolved through cracks at the 

 bottom of the sea, which, forming gypsum with the lime it found, 

 stopped up these cracks, others being however produced from time to 

 time by new movements in the earth's crust, so that alternations of 

 gypsum and limestone were effected. In like manner the dolomitic 

 rocks of the district are inferred to have a metamorphic origin, the 

 needful gaseous emanations having acted on limestones. With respect 

 to the rock-salt, its occurrence in alternating lenticular portions amid 

 the dolomite and gypsum of the zechstein, it is supposed, might 

 arise from the presence, in the waters, of the carbonates of lime and 

 soda, and the simultaneous emission of sulphurous and hydrochloric 

 acids, or of chlorine with the chloride of magnesium from vents at 

 the bottom of the sea, the abundance of each varying, sometimes the 

 sulphurous acid being the most abundant, sometimes chlorine, and at 

 others chloride of magnesium. 



M. Elie de Beaumont communicated to the Society an extended 

 note on the most ancient systems of European mountains, in which, 

 after adverting to his well-known labours on the subject of the eleva- 

 tion of mountain systems, the first account of which was read before 

 the Academy of Sciences of Paris in June 1829, he alludes to his 

 continued researches in the same field, and describes four systems, 

 succeeding each other in the order of geological time, to which he 

 assigns the names of the Finisterre, the Longmynd, the Morbihan, 

 and the Westmoreland or Hundsriick systems. 



It would be impossible to give a correct view, in the limits to which 

 we are necessarily restricted in an address of this kind, of the mass 

 of matter connected with his subject which M. Elie de Beaumont 

 has brought forward in this memoir. We must refer to the paper 

 itself for tables and calculations which are essential to the right un- 

 derstanding of his communication, one which, moreover, is drawn up 

 in a very condensed form, and therefore difficult of satisfactory abridg- 

 ment. 



M. Elie de Beaumont remarks that during the greater part of his 

 labours on mountain systems he had used a graphic method of record- 

 ing his observations, employing a stereographic projection on the 

 horizon of Mont Blanc, which he had calculated and had engraved 



