374 Mineralogy and Geology of Nova Scotia. 



fine powder, and fuses at a heat little exceeding that required 

 to melt brass. In a few places, the whinstone is cleft into 

 layers, which have a vertical position, and east and west direc- 

 tion, like slate. Many portions of it have separated in straight 

 lines, leaving pieces with one, two, or more plain surfaces ; 

 and, in a few instances, all the surfaces are plain, and the 

 pieces have six faces, which are sometimes nearly square, but 

 far more frequently trapezoidal. It may be observed, that the 

 stones which have one plain surface can frequently be broken 

 by the hammer at right angles with, but never in a line pa- 

 rallel to, the plain surface, although they sometimes break in 

 that direction when exposed to fire. Consequently, a stone 

 which has the form of a cube, or parallelopipedon, is spoiled 

 for a building-stone by attempting to break it in the middle, 

 as it is sure to separate in a diagonal direction. It is not easy 

 to find a block of whinstone 3 ft. in diameter which does not 

 contain a number of fragments (for the most part of an an- 

 gular form), which are distinguishable by a different shade of 

 blue, a coarser or finer grain, and a different direction of 

 their fracture. In many instances these fragments compose 

 the greater part of the stone. 



As every variety of our whinstone shivers to pieces when 

 exposed to fire, and the blocks which are exposed to the 

 air all show a disposition to separate, sometimes in straight 

 lines, but far more frequently into irregular fragments, I con- 

 ceive that the greater part of the masses of this rock were, at 

 some former period, broken pieces thrown together, without 

 order, with their interstices filled by the sand which it forms 

 as it decays (a state in which it may be found in many 

 places under peat and turf), and that, by a recrystallisation of 

 the sand, they became again solid rocks ; which, being com- 

 posed (with the exception of the part newly formed) of frag- 

 ments, whose natural lines of fracture were in many different 

 directions, would be incapable of breaking in any uniform 

 manner, either under the hammer, or when exposed to fire 

 or frost. Although the fact is well known to those who are 

 constantly employed in quarrying stone, it may be useful to 

 some persons to know, that building-stone can be most easily 

 procured from whinstone, in those situations where the 

 greatest proportion of stones with what are called smooth 

 faces are found. Whinstone (that which has a regular frac- 

 ture not excepted) frequently contains rolled pieces of blue 

 limestone, which, when first broken, cannot be distinguished 

 from the whin in which it is embedded, except by its fracture, 

 which is rather cubicogranular than splintery : but, after a few 

 days' exposure to the atmosphere, it becomes brown, and 



