62 MINERALS AND GEOLOGY 



where it appears occasionally to replace the mica of these rocks. It 

 occurs also in large flakes in some of the beds of iron-ore associated 

 with the Laurentian limestones, as at Hull, on the Ottawa. In other 

 places, graphite forms large lenticular masses, or actual beds a foot 

 or more in thickness, in these limestones. Occasionally also, it occurs 

 in the form of distinct veins, traversing different strata of the Lauren- 

 tian series. The more important localities comprise, the townships- 

 of Buckingham, Lochabar, Petite Nation, and Grenville, on the left 

 bank of the Ottawa, where this useful mineral occurs in comparative 

 abundance, and is more or less largely worked. Other localities com- 

 prise, more especially, the township of Burgess in Lanark county, 

 and Loughborough and Bedford in Frontenac ; but small quantities 

 are met with in almost every locality in which crystalline limestone 

 occurs. Graphite is found also in thin coatings and finely disseminated 

 scales amongst many of the altered slates of the metamorphic region 

 south of the St. Lawrence (See Part V.), as in Melborne, Shipton, 

 and elsewhere, but nowhere in workable quantities. The chief 

 employment of graphite or plumbago is in the manufacture of draw- 

 ing pencils, and refractory crucibles, the common kinds and refuse 

 being used as a polishing material for stoves, grates, &c. It is also 

 occasionally employed to remove friction in machinery. 



2. Sulphur : Normally, in Ortho-Rhombic crystals (chiefly acute 

 rhombic octahedrons), and in granular masses of a yellow or yellowish- 

 grey colour. H = 2.5 or less ; sp. gr. 2.0. Inflammable, burning 

 with blue flame and sulphurous odour, and melting into brownish- 

 yellow drops which become pale-yellow on cooling. 



In Canada, sulphur occurs very sparingly in the simple state : chiefly 

 as an efflorescent crust on specimens of decomposing pyrites from 

 Lake Superior, and elsewhere. It is also occasionally deposited as 

 an incrustation from springs containing sulphuretted hydrogen. In 

 this condition, mixed with carbonate of lime, it occurs in the Town- 

 shid of Charlotteville, (Lot 3, Con. 12,) Norfolk County, Ontario. 

 It is found also here and there, as first pointed out by Dr. Bigsby, 

 in the form of minute crystals, and in earthy coatings, on some of 

 the lower thin-bedded limestones around Niagara Falls. 



B. NATIVE METALS. 



2- Native GoM: Golden yellow ; malleable: Regular in crystalliza- 

 tion, but occuring chiefly in small granular or leafy particles imbedded 



