582 Mineralogy and Geology of Nova Scotia, 



dicular rock, a cavity, equal perhaps to six cubic feet, which 

 seemed to have been exposed to the air for several years, by 

 the falling off of a part of the rock which had covered it. This 

 cavity appeared to have been not long before occupied by a 

 mass of pyrites. The greater part was decomposed, and lay 

 at the bottom, a blackish grey powder, strongly impregnated 

 with vitriol. Mixed with this powder there were several 

 pieces, of the weight of 1 lb. or 2 lb., of the common granu- 

 lar pyrites, which is generally completely decomposed by an 

 exposure of twenty years to the air; yet the roof of this 

 cavern, and the sides as far down as the pyrites had fallen off, 

 were completely covered with crystals, some of which were 

 half an inch long. Collections of crystals generally seem to 

 be connected with stones in a state of decay. In the granite 

 district of the township of Halifax, there is a tract where spe- 

 cimens of crystallised quartz are frequently found, part of 

 which is of a light purple colour. It is generally attached 

 either to a kind of conglomerate formed of granite partially 

 decomposed, cemented by quartz, or to a mixture of quartz 

 with felspar in a state of decay, containing small cavities filled 

 with China clay. 



The appearance of the large masses of rock seems to in- 

 dicate that the veins of every kind found in them were once 

 fissures, and have since been filled by metallic ores, or some 

 other mineral substance which formed a part of the general 

 mass ; and which, dissolved in a fluid or in a gaseous state, 

 and impelled by that kind of attraction which causes the union 

 of particles of matter which are all of one kind, have filled up 

 these vacant spaces ; thus forming collections of many sub- 

 stances useful to man, by drawing their materials from a mixed 

 mass. 



In referring to attraction for the explanation of certain 

 combinations, I wish it to be understood that the term is used, 

 not to cover, but to avow my ignorance. It might be defined 

 to be a law which governs certain physical actions of which we 

 do not know the causes. All kinds of attraction are, doubtless, 

 effects as well as causes ; but they are mostly the effects of 

 causes which man has not discovered. Thus a lie made from 

 the ashes of wood which grows near Halifax, or on any other 

 vitriolic soil, will be found to contain potash, and another salt 

 now called sulphate of potash. This last cannot be dissolved 

 in less than sixteen times its weight of cold water : the potash 

 will dissolve in less than its weight of water ; consequently, 

 by evaporating the lie, the sulphate of potash maybe crystal- 

 lised and separated, while the potash remains dissolved. This 

 might be explained by saying, that, when this salt formed 



