Magnesian mica or phlogopite occurs abundantly, in small scales, in the crystalline limestones of the Laurentian system, but sometimes also in crystals sufficiently large to be economically available. These are generally met with near bands of quartzite, or of pyroxenic gneiss, limiting the limestones, or near to some interstratified mass of a similar character, and they are usually associated with other minerals. Among these, in addition to quartz, pyroxene and feldspar, there occasionally occur tabular spar, apatite, sphene, iron pyrites, idocrase, garnet, tourmaline, zircon, and sometimes corundum. In Grenville, where the mineral is imbedded in massive pyroxene rock, close alongside of a band of crystalline limestone, crystals of mica have been obtained, giving sheets measuring twenty-four by fourteen inches. In North Burgess, where it has been mined by Mr. Cowan, on lot 17, range 9, the mica is imbedded in a soft pyroxenic rock, running apparently N. E. and S. W., and limited by a band of quartzite on the southward side. The mica here appears to run for seventy-five yards in pretty regular bands, and some of the sheets, after being dressed, are as much as twenty inches square; some have been obtained measuring twenty by thirty inches.-Laurentian.

Plumbago or black lead.

1. Pointe du Chêne Graphite Mine, County of Argenteuil... Russell & Co., Kingston. a. Specimen of plumbago from a bed.

The crystalline limestones of the Laurentian system are very generally marked by the occurrence of graphite or plumbago, in small scales, which are often so thickly disseminated in particular bands of the rock, as to give them a black or dark grey color, distinctly marking its stratified character. It occurs also in beds, in sufficient purity and quantity to be economically available. The workable beds which have been observed, are chiefly in various townships on the north side of the Ottawa. They occur in many localities, at considerable distances from one another, but several of the exposures are probably repetitions of the same bed, or, at any rate, of beds approximately equivalent, in repetitions of the same band of limestone. The whole Laurentian series is so corrugated, that the outcrop of one of these bands of limestone, in the counties of Argenteuil and Two Mountains, followed through all its windings, in an area of fifty miles northward by twenty miles eastward, measures upwards of 200 miles. A bed of pure graphite occurs in the Augmentation of Grenville, and has been traced at intervals, for a distance of about three miles, running a little east of north. One of the exposures, occurring on lot 3, range 2, has been mined, to a small extent, by Messrs. Russell & Co. At the opening of the excavation, it shewed a thickness of about ten inches, but the pure graphite was found to form a lenticular mass, which appeared to be separated from other masses of the same character by intervals, in which the graphite became intermixed with the limestone. It is probable that a number of these, running through the rock at the same horizon, may represent the general character of the workable beds. On lot 3, range 6, the bed becomes three feet thick, but here the quality is impaired by the presence of foreign earthy matters, which, however, can scarcely be detected by the eye.-Laurentian.

Asbestus.

1. St. Joseph seigniory..

a. Specimen of asbestus from a vein.

... Geological Survey.

Asbestus, generally a fibrous serpentine or chrysotile, occurs in veins cutting the serpentine of the Eastern Townships.-Quebec group, Lower Silurian.

Friable Sandstone.

1. Pittsburgh, lot 20, range 1.

a. Specimen of sandstone as sent to foundries.

......A. Cowan, Kingston.

This crumbling sandstone occurs in a bed upwards of twenty feet thick, and is in much demand for iron foundries, being used to protect the sides and bottoms of the furnaces. It is supplied to the founders of Montreal at $3, and to those of Toronto at $2.50 per ton, after being carried about 170 miles, in opposite directions, to these places. About 1500 tons are consumed in the foundries of these two cities.-Potsdam formation, Lower Silurian.

Fire-Clay.

1. Dundas

a. Specimen of fire-clay.

....Geological Survey.

This clay is derived from an argillaceous band twenty feet in thickness, near the base of the Clinton formation. The rain washes the clay from the bank, and deposits it in the bottom of pools at its foot. When the water dries up in these, the clay is dug from them, and is used in the iron foundries at Dundas and at Hamilton. From the neighborhood of Dundas, the Clinton formation strikes south-westward, and after folding over an anticlinal axis, which runs southward of west from the extremity of Lake Ontario, it returns on the south side of Lake Ontario, towards the Niagara River. The same clay band is thus again met with in the escarpment near the village of Ancaster. The clay has only lately come into use, and not much is yet known regarding its merits, but it is said to answer a good purpose, and in Mr. Gartshore's foundry, at Dundas, has entirely superseded the fire-clay formerly imported from the United States.-Clinton formation, Middle Silurian.

2. St. Foy, near Quebec.

a. Specimen of clay.

b. Piece of pottery made from the clay.

Michael Finley, Quebec.

This clay, which is represented by the contributor to be of a refractory nature, forms a considerable deposit at Belmont, the property of Mr. J. W. Dunscomb.-Drift.

This building stone is derived from one of the bands of crystalline limestone of the Laurentian series. It occurs on the property of Mr. McLaren, close upon the margin of the Lac des Chats, one of the expansions of the Ottawa; where a great supply of the rock might be obtained. It has been used by the Board of Works in the construction of a bridge over the river Madawaska, the mouth of which is near to this limestone.-Laurentian.

2. Phillipsburg, St. Armand

.....

a. A foot cube of limestone, dressed.

C. R. Cheeseman, Phillipsburg.

The exposure of limestone from which this stone is derived, occurs within a mile of Phillipsburg, Missisquoi Bay, on the land of the exhibitor, near the line of a proposed railway. The rock is compact and crystalline, dresses easily, and appears to have considerable strength. A few obscure fossils are met with in the rock, belonging to the genera Pleurotomaria and Holopea. Higher in the series, the organic remains are more distinct, and shew the formation to be equivalent to the Calciferous.-Quebec group, Lower Silurian.

The specimens of building stone from Caughnawaga, St. Dominique, and East Hawkesbury, 3-5, are all from one geological formation, the Chazy; which in the area indicated by the distribution of the places named, is composed of massive beds, yielding blocks of stone fitted for the purposes of canal locks and railroad bridges. The quarries of Caughnawaga have supplied a large amount of material for the upper locks of the Lachine Canal, and those of the Beauharnois Canal. That of Hawkesbury, as well as a quarry on the same formation on Isle Bizard, has furnished blocks for the Carillon Canal. The same formation, near Montreal, and on Isle Jesus, near Terrebonne, has been resorted to for similar blocks for the lower locks of the Lachine Canal. In all the places named, the beds abound

in the remains of encrinites and cystidians, and the peculiar crystallization of these, give to the rock a crystalline texture, which constitutes one of its valuable characters. There is occasionally some admixture of magnesia in the stone, and after long exposure to the atmosphere it assumes a yellowish tinge. The St. Dominique stone is more compact than that of Caughnawaga, and has been used for the purposes of the St. Lawrence and Atlantic Railway.-Chazy formation, Lower Silurian.

a. A foot cube of limestone, dressed. The stone of Pointe Claire and Cornwall, 6-7, belongs to the formation next above the Chazy. It is black, compact, and thick bedded. At Mille Roches, near Cornwall, it has supplied stone for the construction of the locks of the Cornwall Canal, and at Pointe Claire, has furnished the stone used in building the piers of the western half of Victoria Bridge, while that used for the other half was brought from what is said to be the same formation, at Isle la Motte in Lake Champlain. On the north side of the Pointe Claire quarry, there is a vertical exposure of thirty feet of massive strata, varying in thickness from one to three feet, the blocks obtained from which, for the bridge, ranged from four to seven tons.-Birdseye and Black River formation, Lower Silurian.

The Trenton formation, which is the next in succession above the Birdseye and Black River, yields excellent building stone at Montreal, at Chevrotière, nearly forty miles above Quebec, and at many intermediate places. The best stone at Montreal is derived from a ten feet band of grey bituminous granular limestone, in beds of from three to eighteen inches thick at the bottom, passing at the top, into a black nodular bituminous limestone; which is interstratified with black bituminous shale, in irregular layers of from one to three inches. This grey limestone, which is near the base of the formation, is a mass of comminuted organic remains, which consist largely of the ruins of crinoids and cystideans. The crystallization of these fossils gives a crystalline character to the rock. A considerable number of quarries are worked upon this band of grey limestone, there being four principal ones near Montreal, and the best houses of the city are built of the stone. The quantity of stone annually quarried in the immediate vicinity of Montreal is computed to be:

Mouldings, from $0.163 to $3.00, or for a fair moulding, $1.50 per linear foot.
Fluted columns 18 inches diameter,.......for the stone, $1.00 per rising foot.

Heavy rough stone, from 6 to 30 cubic feet, from....... $0.30 to 0.50 per cubic foot.
Very heavy rough stone, say 60 cubic feet,...

$1.00

"

The strata in the neighborhood of the city are much traversed by trap dykes, which probably have a connection with an intrusive mass extending over 700 acres, and constituting Mount Royal, from which the city and island take their name. Some of the quarries display a number of these trap dykes, which run in several directions and intersect one another. In some instances, the limestone, having been removed from among them, the dykes are left standing up several feet above the bottom of the quarries, representing in a marked manner the various details of the cracks they once filled.

In the seigniory of La Chevrotière, a very excellent limestone for building is obtained between three and four miles back from the St. Lawrence. It usually goes, however, under the name of the Deschambault stone, in consequence of its being put on board of boats at this place. The stone is of a yellower or warmer grey than the Montreal stone; it is more even in its tint, and becomes somewhat less discolored by weathering. It is more granular and more easily cut, being softer and tougher, but it does not take so fine nor so sharp an edge, nor does it pick so well. Three beds of pretty uniform character are worked; the top and bottom ones are eighteen inches thick each, and the middle one three feet. There is said to be a fourth bed beneath, with a thickness of four feet, which has not been quarried. The strata are so nearly horizontal, that it is difficult to determine their dip; it is therefore probable that the stone will spread to a considerable extent in the vicinity. Along the concession line, it is known for twenty-six acres to the S. W., and five acres to the N.E., and on the road across the concession, it is visible for a breadth of ten acres; beyond which, in sinking wells to a depth of twenty feet in blue clay, no rock is met with. The produce of the quarries of La Chevrotière has a deserved celebrity in Quebec, where it has been used in the construction of churches and other buildings.-Trenton formation, Lower Silurian.

Dolomites or Magnesian limestone.

1. Owen Sound......

a. A foot cube of dolomite, dressed.

....

Geological Survey.

This beautiful and enduring stone can be obtained in unlimited quantities, the formation from which it is derived being here 150 feet in thickness, and divided into beds varying from a few inches to six feet. This stone possesses the very great advantage of being free from any substance producing stains. Its color rather improves with the weather, and the beauty of no building erected of it appears, as yet, to be marred by the growth of lichens. It is especially adapted for heavy masonry, and blocks of any required size can be obtained. The quarries are about half a mile from the harbor.-Niagara formation, Middle Silurian.

......

2. Noisy River Falls, Nottawasaga, lot 3, range 11 ..... Geological Survey. a. A foot cube of dolomite, dressed.

This stone is from the lower part of the Niagara formation, and is rather more compact than the Owen Sound specimen. The cliff is here about fifty feet high, and might be quarried with the greatest facility. Few of the beds are less than two feet in thickness, and some of them are about five feet, but the locality is not near to any navigable water or railway.-Niagara formation, Middle Silurian.