248 



Mr. Whitney being present, stated that he had full confidence 

 in the results of his own examination of the mineral in question, 

 and he must still consider it a new mineral. 



The President exhibited to the Society specimens of dif- 

 ferent American Sandstones and spoke of their various 

 adaptation to building purposes. The specimens were the 

 Potomac, New Jersey, Connecticut, and Nova Scotia Sand- 

 stones. In his opinion of their comparative value, he coin- 

 cided in general with the views expressed at the last meet- 

 ing. On that occasion he had spoken more in favor of the 

 Potomac Sandstone, he said, than the nature of the stone 

 would warrant. He was now satisfied that it was inferior 

 to the others. A letter was read by the Secretary, addressed 

 to the President by his request, from Mr. T. J. Bayley, a 

 stone-cutter, on the comparative value of the American 

 Sandstones, giving that from New Jersey the first place, 

 and the Connecticut the next, but hesitating in ex})ressing 

 an opinion as to the Nova Scotia stone for want of sufficient 

 practical acquaintance with it. The President said, he did 

 not think Mr. Alger's suggestion of the substitution of 

 granite for sandstone would be extensively adopted in the 

 construction of public buildings, on account of the superi- 

 ority of the latter in color and its greater softness. 



Prof. Rogers said, he was unwilling to allow the Nova Scotia 

 stone to be passed over as inferior to the others. He had seen it as 

 it came from the quarry, showing no marks of atmospheric action, 

 and of a compact, homogeneous structure. It has the peculiar 

 advantage of occurring in very large beds without any percepti- 

 ble grain, splitting easily in any direction, and is well adapted to 

 the purposes of coarse statuary. 



Prof. Rogers laid before the Society a theory to account 

 for the origin of the green sand of New Jersey. 



This sand is found under the microscope to be sharp on its 

 edges, not rounded, or showing any signs of attrition. It is in 

 the form of small granules, like grains of gunpowder, of a dark 

 olive, sometimes greenish color, from the presence of protoxide 



