OF CENTRAL CANADA PART II. 



75 



FIGS. 37 to 41. 



combinations of cube 

 and octahedron, in sim- 

 ple octahedrons, pen- 

 tagonal dodecahedrons, 

 &c. (Figs. 37 41.) 

 Found still more fre- 

 quently in granular, 

 nodular, and other irre- 

 gular masses. H = 

 6.0 6.5 ; sp. gr. 4.8 

 52. BB, emits sul- 

 phurous fumes, and melts into a dark magnetic globule. One hun- 

 dred parts contain: Sulphur 53.3, Iron 46.7, but a small portion of 

 the iron is occasionally replaced by cobalt or nickel. Many varieties, 

 also, contain traces of both ggid and silver. (In this connectiou, it 

 may be observed that a percentage of 0.01 is equivalent to 2 oz. 18 

 dwts. 8 grs. (troy) in the ton of 2000 Ibs., or to 3 oz. 5 dwts. 8 grs. 

 (troy) in the British ton of 2240 Ibs.) 



Iron Pyrites is of exceedingly common occurrence. It is present, 

 more or less, in almost every mineral vein ; and occurs also, in crystals, 

 grains, and irregular masses, in rocks of all ages and of various kinds. 

 It sometimes forms the substance of organic remains, as in examples 

 of Trilobites, &c., from the Utica Slate of Whitby and other localities. 

 In this condition it arises most probably from the alteration of carbo- 

 nate of iron. 



In the Laurentian rocks of North Hastings and adjacent counties, 

 in the copper-bearing series of Lake Superior, and in the altered 

 strata of the Eastern Townships south of the St. Lawrence, auriferous 

 varieties have been noticed ; but the amount of gold in these is scarce - 

 ly sufficient to defray the cost of its extraction. In Elizabethtown 

 (Lot 19, Range 2), near Brockville, and elsewhere in this vicinity, 

 some large beds or veins of a cobaltic variety occur. Large veins 

 occur also in Clarendon, on the Ottawa ; in Terrebonne and Lanoraie ; 

 in Hastings, and throughout that district j as well as on the north 

 shores of Lakes Huron and Superior. Extensive deposits are like- 

 wise seen in some of the Eastern Townships (Garthby, Ascot, <fcc.) 

 all of which are likely to become available at no distant day, in the 

 manufacture of sulphuric acid. Cubical crystals of large size occur 



