Scientific Meeting in Germany. 289 



pistazite and thin layers of Wollastonite. Parallel to the blende 

 strata is a bed of brown garnet, containing mica and dichroite, 

 and in like manner subordinate to the gneiss. There were similar 

 layers of white cobalt and copper pyrites imbedded in quartzose 

 mica-slate. This occurrence of zinc blende is peculiar, and does not 

 seem to harmonise well with our common views regarding mine- 

 ral veins. 



Sir Roderick Murchison exhibited the plates of a new edition 

 of his Siluria, and explained the most important additions that 

 had been made to our knowledge of the Silurian rocks during the 

 last three years. He maintained that it was now proved, both by 

 physical and zoological facts, that the Bala beds of Wales were 

 identical with the Caradoc beds, resting similarly upon the Llan- 

 deilo formation, in the lower division of which a number of new 

 fossil species had been discovered. He then referred to the group 

 of the Llandovery rocks in South Wales (containing the Pentam- 

 erns Oblongus) lying between the lower and upper Silurian, and 

 closely connected with each. Finally, he exhibited figures of gi- 

 gantic crustaceans (pterygotus) found in the upper Silurian beds? 

 which had been published by Mr. Salter in the Decades of the 

 Geological Survey. 



M. Ch. St. Claire Deville exhibited his topographical map of the 

 island of Guadaloupe. In the centre rises the cone of the Son- 

 friere, surrounded by a crater of elevation. The latter consists of 

 dolerite ; the central one of a trachyte, the feldspath of which ap- 

 proaches in chemical composition to Labrador. The Sonfriere i s 

 an extinct volcano. At the request of Sir Roderick Murchison 

 and Mr. Merian, the speaker then communicated his views with 

 regard to the volcanoes of Italy and their mode of action. He 

 held Von Buch's theory of elevation, but laid considerable stress 

 upon etoilement. Vesuvius and Etna, as central volcanoes, he re- 

 garded as the points of intersection of radiating fissures, in which 

 volcanic action burst forth. The Phlegrean fields, the Rocca Monfi- 

 na, the Lago d'Amsanto, Ischia, and other points he considered 

 as lying upon these fissures. 



Herr von Carnall exhibited maps of the coal formation in Rus- 

 sian Poland on a scale of 1-20,000, and of Lower Silesia, at which 

 Beyrich, Rose, and Roth had been working for years, on a scale 

 of 1-100,000. 



Director Nauck, with reference to the question agitated on 

 Monday by Professor Blum, reported the result of a series of ex- 



