150 Proceedings of Philosophical Societies. [Fbb. 



From the great similarity in their chemical composition, Mr. 

 Hisinger objects to the ranking of sparry ironstone and brown spar 

 under different genera, as Werner, from regarding only external 

 cliaracters, has been led to do. 



At the meeting on the 4th of December a communication was 

 read from Capt. Brown, of the Forfarshire Militia, containing 

 descriptions and drawings of some rare and also of some new shells, 

 found on the coast of Noithumberland. 



At the same meeting, Professor Jameson read a paper on con- 

 glomerated rocks. These, he remarked, occur in primitive, tran- 

 sition, and floetz country : the primitive conglomerates are conglo- 

 merated gneis, conglomerated mica slate, conglomerated granite, 

 and conglomerated porphyry rock : the transition conglomerated 

 rocks are greywacke, sandstone, and limestone ; and the floetz 

 conglomerates are sandstone and trap tuff. Mr. Jameson, from the 

 crystalline character of these rocks, conjectures that all of them are 

 original chemical deposites, and that therefore the quantity of me- 

 chanical matter on the crust of the earth is much less than is gene- 

 rally supposed. 



At the meeting on the 8th of January, IS 14, two communica- 

 tions from Capt. Laskey were read. The first gave an account of 

 shells Iiaving been found in a bed of sand and clay, which was cut 

 through in the line of the Ardrossan canal, near Paisley. This bed 

 is situated about 40 feet above the present level of the Clyde. The 

 shells found are chiefly the following : turbo littoreus, rudis, tere- 

 bra; area minuta, nucleus; patella pellucida, vulgata ; buccinum 

 lapillus, undatum : mytilus edulis ; Venus islandica, striata, lite- 

 rata, pecten opercularis ; balanus communis ; anomia ephippium ; 

 tellina plana ; nerita littoralis, glaucinum ; mya truncata ; trochus 

 crassus ; and carduuni echinatum. They are generally somewhat 

 worn or broken ; but all of them are at this day to be found recent 

 or alive in the frith of Clyde and its shores, at the distance, how- 

 ever, of 20 miles from this spot. The second communication 

 described a fossil asterias found in a bed of sandstone near Abor- 

 lady : it seems most nearly allied to Asterias multiradiata. 



Capt, Laskey also laid before the Society some specimens of 

 wavellite in slate clay, from Loch Humphry, in Dunbartonshire. 

 This is the second time this rare mineral has been observed in 

 Scotland. It was first discovered in Scotland, in the isle of Glass, 

 several years ago, by Mr. Neil, Secretary to the Wernerian Society. 

 At the same meeting, Professor Jameson read a series of 

 mineralogical observations and speculations on stratification, veins, 

 and coal. Mr. Jameson considers stratification as having been 

 effected more by a simultaneous crj'stallization than by successive 

 deposition, and that the seams of the strata are merely particular 

 separations eifecied in the crystallizing mass, in the same manner as 

 the seams are formed in distinct concretions, or tlie lamina in the 

 slaty structure. Hence it follows that any two contiguous portions 

 of granite are of simultaneous formation. The same must be the 

 case with any two contiguous portions of granite and gneiss, or of 



