10 Proceedings of the 



searching examination for boracic acid in prehnite. In all these localities 

 the mineral had been recognised by its crystallographic characters, no 

 analysis of a British specimen having yet been published. A specimen 

 from Glen Farg had been examined by Dr Heddle, and the analysis 

 showed nothing different from those made of foreign specimens, with the 

 exception of -28 per cent, of oxide of iron ; and as a second analysis 

 (made upon crystals apparently absolutely pure) gave '24 per cent, Dr 

 Heddle was inclined to think that the iron is the colouring matter, giving 

 the mineral its light yellowish-green or asparagus stone tint. 



The following gentlemen were then elected members of the Society : — 

 James Wardrope, Esq. ; Hugh Redpath, Esq. ; Stevenson Macadam, 

 Ph.D., F.C.S. 



Wednesday, February 28, 1855. — Robert Chambers, Esq., President, 



in the Chair. 

 The following Donations to the Library were laid on the table, and 

 thanks voted to the respective donors : — 1. (1.) Transactions of the Royal 

 Society of Edinburgh, Vol. XXI., Part I. Session 1853-4. (2.) Pro- 

 ceedings of the Royal Society of Edinburgh. Session 1853-4. From 

 the Society. 2. Transactions of the Michigan State Agricultural Society. 

 4 vols. 8vo. From the Michigan State Agricultural Society, through the 

 Smithsonian Institute. 



I. On the late Severe Frost. By Hugh Miller, Esq. 



In the hope of attracting attention round our shores to one of those ca- 

 tastrophes in the animal world which throw light on the disappearance of 

 species in geological history, Mr Miller stated he had inserted in the 

 Witness of last Saturday the following paragraph : — 



" The present intense frost, coincident at new moon with a stream tide, 

 has killed many of the littoral shell-fish around our shores, and they now 

 lie by thousands and tens of thousands along the beach. On the beach 

 below Portobello, and for at least a mile on the western side of the 

 town, they are chiefly of two species, — Solen siliqua, or the edible spout- 

 fish or razor-fish, and Mactra stultorum, or the fool's cockle, both of 

 them molluscs, which burrow in the sands above the low water line of 

 stream tides. The spout-fishes, when first thrown ashore, were carried 

 away by pail and basketfuls by the poorer people, and yet of their shells 

 enough remain, in the space of half a mile, to load several carts ; but the 

 fishes themselves, devoured by myriads of birds, chiefly gulls, have al- 

 ready disappeared. The Mactra, though they may be picked up in some 

 places by basketfuls, are less abundant. It is probable, however, that 

 both species will be less common ,on our coasts than heretofore for years 

 to come ; and their wholesale destruction by a frost, a few degrees more 

 intense than is common in our climate, strikingly shows how simply, by 

 slight changes of climate induced by physical causes, whole races of ani- 

 mals may become extinct. It exemplifies, too, how destruction may fall 



