S72 Scientific Intelligence — Geology. 



conceive how much all these make me regret the impossibility 

 of my visiting those regions, so interesting to the geognost.'"' 



5. Discovery of Carbonate and Sulphate of Lithia in a 

 Spring. — A mineral spring recently discovered at Rosheim, be- 

 tween Strasbourg and Schelestad, has been found to contain 

 two substances hitherto unknown as ingredients of spring water, 

 viz. sulphate and carbonate of lithia. 



6. Siliceous Si?iter of Ice/and. — M. Robert, in his account 

 of the geology of Iceland, mentions, that in the vicinity of the 

 Geysers, the siliceous concretionary deposits constitute a mass of 

 no less than four leagues in length. 



7. Native Mercury in Granite. — M. Alluaud sen. of Li- 

 moges, has communicated to the Philomathic Society of Paris a 

 notice regarding the mercury of Peyrat-le-Chateau, in the de- 

 partment of Haute Vienne. The district is composed of differ- 

 ent varieties of granite passing into each other, and also into 

 pegmatite, gneiss, and similar rocks. It is in the decomposed 

 quartzose granite of the esplanade of the ancient castle that dis- 

 seminated liquid mercury has been found at various isolated 

 points. 



8. Fall of part of Dent du Midi. — M. Elie de Beaumont 

 read to the Geological Society of France a communication from 

 M. Lardy upon the fall of a part of the Dent du Midi, one of 

 the high Alps. This fall took place on the 26th of August 

 1835. M. Lardy states, that on Tuesday the 25th of August 

 there was a violent storm in the evening all round the Dent 

 du Midi ; and it was asserted that its peak was often struck by 

 the thunderbolt. Next day, the 26th, between ten and eleven 

 ©""clock in the morning, a very considerable portion of this peak 

 suddenly broke off from its eastern edge, and precipitated itself 

 with a dreadful crash upon the glacier which is situated upon 

 the southern side of the Dent, and in its descent drew along 

 with it an immense proportion of this glacier. This enormous 

 mass of stone and ice fell into the deep ravine which separates 

 the Dent du Midi from the Col dc Salenfe, into which the tor- 

 rent of St Barthelemy runs. Speedily there issued from this 

 gorge, through which this torrent flows to the valley of the 

 Rhone, as it were, a mountain of black and viscid mire, on the 



