586 Mineralogy and Geology of Nova Scotia.^ 



inhabited by a race of savages who carefully preserve the 

 forest, the formation of iron ores (useless to them) is retarded. 

 But that when they are replaced by a civilised race, whose 

 habits lead them to destroy the forest, the ores of this (to 

 them) most useful of metals are rapidly accumulated. As 

 many of our hills of common conglomerate contain a very 

 considerable proportion of iron, some of them might be worth 

 the trouble of an essay intimating the manner in which they 

 must be smelted in large furnaces. It is to be observed, that 

 iron ore is valuable rather for the good quality, than the large 

 quantity, of metal which it gives; for, as iron is a com- 

 bustible metal, it is always found necessary to add to rich ores 

 a large quantity of some kind of stone or sand, partly for the 

 purpose of forming a covering of glassy cinders to protect it 

 from burning, by excluding the air. The late Mr. Pernette 

 showed me a piece of cast iron which he had melted from the 

 common conglomerate. By his assay it had yielded a fourth 

 part, or 25 per cenU 



Slate usually stands vertically, and runs in a direction a 

 little north of east, and south of west. It is almost always 

 rent with fissures for a considerable depth, most of which cut 

 obliquely across the natural line of cleavage of the slate. 

 Some of these fissures are united by veins of pyrites ; others 

 open, with opposite faces coated with oxide of iron. The 

 varieties to be found in the common slate are numerous, al- 

 though, in general, the difference between them is not great. 

 When the rock is naked and smooth upon the surface, the 

 layers which mark these varieties are very visible : a few of 

 them are siliceous, and nearly as coarse as whinstone. Very 

 rarely a thin layer occurs, which will split like roofing slate. 

 The greater part of the slate in which the pyrites is mostly 

 decomposed splits easily, though not with regularity. There 

 are some layers which show no disposition to cleave like slater 

 the most remarkable of these are, a kind of limestone in very 

 thin layers, which usually are of small extent. It is extremely 

 hard and heavy ; strikes fire with steel ; is of a slate colour ; 

 generally contains pyrites, and sometimes granite of the colour 

 of rosin. Like many other kinds of limestone, it decays when 

 exposed to the air, forming a black rotten stone. It burns to 

 a dark sandy lime. I conceive that a portion of the material 

 which forms slate has been introduced into this stone since it 

 has been in its present situation, and that it was originally a 

 common limestone; for I have in a single instance observed a 

 rolled piece of this limestone in common slate, and think it 

 very probable that it was originally of the same kind with that 

 of which many rolled pieces (with the figure of paving stones) 



