120 A POPULAR EXPOSITION OF THE 
gneiss.—3, South Crosby Township, Newborough mine: Bed in 
gneiss, on Mud Lake, 200 feet in thickness.—4, South Sherbrooke 
Township: Bed of 12 feet in gneiss.—5, Hull Township on the 
Ottawa: Dome-shaped bed in gneiss; thickness, about 90 feet.—6; 
Grenville Township, C. E.: Bed of 10 or 12 feet in thickness.— 
7, Grandison Township, C. E., 20 feet bed. The average amount of 
iron in these beds, varies from 60 to 70 per cent. Specular iron ore 
(averaging about 55 per cent. of metal) occurs in a 30 feet bed, in the 
township of McNabb, near the Lac des Chats. Also in “ Iron Island ” 
on Lake Nipissing. Titaniferous Iron (Ilmenite), as already mention- 
ed, forms a bed of 90 feet in thickness, in Feldspar-rock (anorthosite) 
at Bay St. Paul on the Lower St. Lawrence. 
(6). Lead Ore :—This consists of galena or sulphide of lead. 
Mixed with a gangue of calc spar and heavy spar it forms a series of 
narrow veins in the townships of Lansdowne, Ramsay, and Bedford, 
C.W. These veins, which vary in thickness from six inches to a foot, 
belong, probably, to a somewhat more recent period of formation than 
the Laurentian epoch; but as they occur among the Laurentian rocks, 
they are properly mentioned in connexion with these strata. The 
lead ore is very slightly argentiferous, and apparently in no great 
quantity in the veins. It occurs also, under similar conditions, in 
the township of Dummer, Peterborough Co., C. W. 
(c}. Sulphide of Molybdenum :—This mineral (see Part II.) is not 
at present of much value. It forms the source of various molybdeaum 
. compounds, some of which are employed in chemical investigations, 
and occasionally in porcelain painting. It occurs, in small quantities, 
in the Laurentian rocks of several localities, as mentioned under the 
description of the mineral in a preceding part of this Essay ; but in 
workable quantities it has only been found, as yet, at the mouth of 
the Quetachoo River on the north shore of the Gulf of St. Lawrence. 
(“‘ Descriptive Catalogue of the Economic Minerals of Canada in the 
Exhibition of 1862 ”—issued by the Geological Survey.) 
(d). Graphite :—Found in workable quantities in the Augmentation 
of Grenville, on the Ottawa, (see Parr II.) Also in the townships 
of Burgess and Lochaber. The quality is scarcely sufficient to render 
the substance available as a materia] for pencils, but the graphite of 
these localities is well adapted for refractory crucibles, and also as a 
burnishing material for stoves and grates. 
(e). Mica :—This mineral occurs in pieces sufficiently large for 
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