Proceedings of' the Wernerian Society/. 199 



This composition differs from that of all other minerals, so far as 

 the author's knowledge extends ; and shows the substance under 

 analysis to be a hydrated quatersilicate of lime, conformably to the 

 formula, 9 S * C + 16 Aq. 



Sir David Brewster, who possesses a mass of the mineral which be 

 received from Count Vargas Bedemar, has observed crystallized faces, 

 but so near the general surface, that they cannot be separated. He 

 has also found that it possesses double refraction ; that it reflects a 

 bluish light, and consequently transmits a yellowish one ; and that it 

 possesses no pyroelectricity. He has no doubt that it is a new mi- 

 neral. 



The author proposes to distinguish it by the name of DysclasitCj 

 [}vo xAflfw], as expressive of its remarkable tenacity and difficult fran- 

 gibility. It will, of course, be arranged with the Zeolites. 



The Secretary read an extract from a letter, giving a short descrip' 

 tion of the Stalactitic Caves recently discovered in the county of 

 Tipperary, and exhibited various illustrative drawings. 



Several additional specimens were exhibited from Burdiehouse 

 Quarry ; and Dr Hibbert read a short notice relative to the position 

 of the limestone there, and the relation it bears to the mountain- 

 limestone of Muirhouse and tlie neighbourhood. His observations 

 were to the effect that, by examining some sections of the strata be- 

 tween Burdiehouse and Loanhead, he had now satisfied himself that 

 the limestone of Burdiehouse lies beneath the great bed of mountain- 

 limestone formerly described by him as traversing the country from 

 Joppa towards the Pentland Hills. The order of the strata between 

 them is as follows : — Burdiehouse limestone^^shoXe and thin beds of 

 the same limestone,— sandstone and shale, — sandstone, coal blaes, 

 ironstone bands, and thin seams of codX~^ Mountain limestone — lime- 

 stone blaes — Coal measures. 



Premiums offered by the Wernerian Natural Histoj-y Society. 



Ediwburoh, 10/A May 1834. 



The Wernerian Natdkal History Society offers the 

 following Honorary Premiums ; open unconditionally to all 

 scientific Naturalists : — 



1. Twenty Sovereigns, or a suitable piece of Plate of that value, 

 for the best Geological Account, with a Geognostical INIap, Sections, 

 and Specimens, of the Three Lothians, with as much of the neigh- 

 bourhood as may be required for the elucidation of the districts.— 

 To be given in against December 1835. 



