Proceedings of the Royal Society of Edinburgh. 195 



April 7. — Sir Thomas Makdougall Brisbane, K. C. B. 

 President, in the Chair. The following communications were 

 read : — 



1. Remarks on the Remains of an Oak dug from a Peat-moss 

 near Lanfyne, Ayrshire. By Thomas Brown, Esq. 



[^Tbis memoir published in Vol. xvii. of this Journal.] 



2. Analysis of Levyine. By Arthur Connell, Esq. 



A few years ago, this mineral was described as a new species by 

 Sir David Brewster, on account of peculiar optical properties ascer- 

 tained by himself, and its crystallographic characters, as determined 

 by Mr Haidinger. Berzelius, however, inferred from the analysis of 

 a specimen sent to him by Sir David Brewster, that it is merely a 

 variety of chabazite, its chemical constitution appearing to be. Silica 

 48, Alumina 20, Lime 8.35, IMagnesia 0.4, Potash 0.41, Soda 2.75, 

 Water 19.30. But, from a subsequent explanation, it seemed probable 

 that Berzelius had analyzed not the true levyine, but a mixture of 

 this and chabazite, constituting the specimen which was sent. The 

 author therefore considered it desirable to execute a new analysis of 

 the mineral in question, which he has found to yield the following 

 results ; — 



101.77 



The specific gravity is 2.198, the fundamental crystalline form a 

 rhomb 79* 29', as stated by Mr Haidinger, while that of Chabazite 

 is 94* 46'. Sir David Brewster found the crystals to possess one 

 axis of double refraction, like other rhombohedral crystals, while the 

 optical properties of chabazite are very anomalous. It is impossible, 

 therefore, to consider the two minerals to be the same, without dis- 

 regarding several marked differences. 



April 21. — Sir Thomas Makdougall Brisbane, K. C. B. 

 President, in the Chair. The following communications were 

 read : — 



1. Summary of the Discoveries hitherto made in the Ossife- 

 rous Beds of the Basins of the Forth and Clyde. By Dr 

 Hibbcrt. 



The author gave a summary of the discoveries which Iiad taken 

 place during the course of the session relative to the ossiferous beds 



