lustre. It passes so gradually into talcose schist of the palest colour, as to leave no doubt of their being but coloured modifications of the same rock. In the rock in which the galleries at present worked are situated, a flesh coloured schist is found, of a mixture of talc and quartz. It passes into a subschistose rock of a similar composition, the latter ingredient being in greatest quantity; in fact a talcose quartz rock. This is exchanged a little lower for a dark olive green soft rock, of a schistose structure, but not laminar, the aspect of the fracture being scaly. I think it consists chiefly of hornblende.

216. The copper mines here are situated in the quartz or talc slate just described, a rock of so soft and tender a nature, as to form a very strong objection to the efficient working of them by its frequent failures in the different galleries. At the time I visited the place, they had all fallen in, and consequently no specimens of the ore were obtainable, except such as could be gleaned from the rubbish lying at the mouths of the several galleries. These pointed to vitreous copper, or the sulphuret, the richest ore known. Copper pyrites was also observed, and blue and green copper in small quantity; whether the ore is in the form of veins or beds, it is impossible to judge in the present state of things. The water which issues from the galleries has a specific gravity of is impregnated with the sulphate, and deposits sulphate of copper on the stones over which it flows. These mines evidently have been very productive, to judge by the extent to which they have been worked.

217. On the ridge from which the descent to Boomot commences, micaceous, or perhaps rather an impure talcose schist occurs. It contains a good deal of quartz, below this a decided talcose schist appears, of a greenish hue. In the bed of the torrent, at the foot of the ridge, blocks are found of hornblende rock, containing pure hornblende in bundles of needles, and glassy actynolite, in contact with a reddish felspar. I did not, however, succeed in detaching any good specimens; some rolled pieces of hornblende were found, having the closest resemblance to charcoal, in all save specific gravity. In these, the apparent fibre was most commonly curved, the lustre always dull. The rock from hence to Boomot is entirely talcose, being either a granular mixture of talc and quartz, (talcose quartz rock,) which occasionally becomes quite soft, and disintegrating; oc

casionally a perfect talcose schist, which oscillates, as the rock always does, towards chloritic schist. A granitic mixture of hornblende and quartz is also found in limited quantity, the type in fact of a green

stone.

218. At Boomot, which is situated on an extensive flat, we find the rounded stones so often described, the flat being entirely composed of them; the height above the river is 200 feet, and the extent considerable. The rock in situ is seen, however, at the third of the ascent, and it is chloritic schist, which appears on the other side to pass into greenstone slate. On the left bank a larger flat is seen, being upwards of two miles long, and half a mile, or more, wide in the broadest part. This is also composed of the same rounded stones; these beds can never have owed their origin to any body of water so limited in quantity as the present supplies of this river; and besides these table lands are in reality 200 feet above the present bed. There occurs here an appearance which is of considerable interest; there are two levels, and a considerable difference between them in height, the lower table being nearest to the river. This condition of things certainly reminds one of parallel roads, as they have been called, in some of the glens in Scotland. Similar appearances have been observed by Captain Hall in Chili. The resemblance is the more interesting, because I believe it is now a generally received opinion, that the latter owe their origin to the successive burstings of a lake, at distant intervals of time.

219. On crossing the suspension bridge, a rock very like greenstone slate is found, it passes into the chloritic schist observed below Boomot, and through that, on this side, into a perfect talcose schist, of white, yellow, and blue colours, &c. On the flat no rock is visible, but again in the bed of the stream, which comes down from Dhunpore, the granite rock, which I have called greenstone, is again detected, occasionally passing into a greenstone slate. It contains nests of indurated tale or potstone. The schists are always conformably stratified, that is, they dip to N. E., but the greenstone is generally amorphous. The schistose rocks continue, often verging on chloritic schist, and interstratified with quartz rock as far as the route lies in the bed of the Nullah, which is of great depth and narrowness, the sides of mural steepness laying open, in beautiful natural sections, all the particulars of the rock worthy of notice.

220. It was observed, that sometimes the change from the green schist to the quartz rock was sudden; sometimes a real transition is seen. In general, the schist has a stronger resemblance to the chloritic types, though it is also found a perfect hornblende schist. The dip and inclination of the strata present great local irregularities, the former being sometimes reversed within a few hundred yards, and the latter not unfrequently 90°. The direction appears to follow a curved line, being in the first instance observed as conformable, i. e. N. W. It is then seen to run N., from which point it gradually changes to N. 35° E. In the first case the dip was as usual N. E.; as the direction changes, the strata become wedge-shaped, and assume a vertical position, till at length it is found that the dip is reversed, being finally S. E.

221. From the bed of the Nullah, the route ascends to Dhunpore, where are worked the most valuable and productive copper mines in the mountains. The rocks which are found in the ascent to the Koangola Pass and descent thence are various in character, and a more enlarged examination of this neighbourhood is required to determine their true relations to each other. In the ascent to Dhunpore, quartz rock is the prevailing substance, which passes on the summit of the ridge into a very thin slaty rock of a yellowish colour, exceedingly hard, and composed apparently of quartz with some talc. The laminæ of this are not above a tenth of an inch in thickness. They separate with greatest clearness, are often bent or curved, are rather brittle, and consequently not obtainable of any size. This type might be called slaty quartz rock, in contra-distinction to schistose quartz rock. It passes into the pure amorphous type; argillaceous schist, then succeeds, variously intermixed with limestone more or less pure. The former occurs here of an intense black colour, similar to that of basanite. It has a schistose structure, but never separates into thin slates, the attempt to obtain such generally producing a conchoidal surface, or at least one more or less uneven. It is moderately hard, of a fine grain, receives a good polish, would form a most superior description of writing slate, and is not even inapplicable to the purposes to which basanite is applied. It has a cleavage, or set of natural joints, the surfaces of which present the appearance of a slight iridescence, or pavonine tarnish. This cleavage is most commonly, or at least very often, transverse to the direction of the schistose

structure. It is in contact on two sides, with an argillaceous or siliceous limestone, which in its immediate neighbourhood passes into a perfect rotten stone. What the nature or cause of this caries is, which so often appears to attack rocks of the greatest solidity, no one has yet explained in a satisfactory manner. The unchanged rock is of blue colour, impalpable in composition, with a conchoidal fracture, and in appearance resembling perfectly the most regular limestone. It is, however, a very impure one, being highly charged with argillaceous or siliceous ingredients, or perhaps with both, occasionally it even strikes fire with steel, and approaches the nature of schist. In its passage into the rotten stone it is observed, first to change a little in colour, becoming gradually more tinged with the peculiar mud colour of the latter, which is so far different from the rotten stone of Derbyshire, as to be of a more yellowish than a brownish tinge. The grain is observed gradually to make its appearance, and the rock to be full of joints or cleavages, till at last it is found of a dirty yellow colour, fine grain, very friable, and with a specific gravity of only 0.9. A series of specimens connecting the two extremes has been collected, which shews the progress of the change with great clearness; a rotten stone of bright colour appears to originate in a real argillaceous schist.

222. The rock in the neighbourhood of Dhunpore is, as I have already stated, a quartz rock, it is distinguished for its peculiar shattered and fissured aspect, no trace of stratification being observable except on the great scale. The irregularity of the strata is great, and the change of dip frequent. A mass of red dolomite appears in the middle of it east of the village, and it is in this latter rock that the copper mines are situated. This dolomite is evidently connected with the siliceous limestone on the Dhobree side, in which also a mine is worked, but the produce is inconsiderable. This mine is remarkable, however, for furnishing lumps of limestone, apparently changed by a similar process to that which produced the rotten stone, the result in this case being a perfect chalk; such a change in the surface of limestone fragments is common, and has been noticed in the preceding details; but excepting at Dhobree, I have never met such large pieces so perfectly changed to chalk, These fragments are used as a flux in the reduction of the copper ores.

223. On the Telkhunnee Pass, a brown schist is found, and thence descending to the village of Bissona, various modifications of the same passing occasionally into argillaceous quartz rock. Near the village, a granular rock is seen composed of quartz and indurated clay, having much the aspect of a greywacke. Here a mass of reddish limestone is found imbedded in the slate, in extent about 50 yards by 10, and capable of furnishing a very beautiful marble. Schistose rocks continue to Kirsal, where traces of limestone occur in local conglomerates, in tufaceous masses, and even as an ingredient in the more compound schists. The prevailing type approached to that of stone slate, being of a composition almost impalpable, moderately hard, and of colours varying from greenish grey through yellowish grey, to reddish and purpleish grey. These specimens are seldom of a perfect slaty structure, the cross fracture is easily obtained, and it is often conchoidal. Below Kirsal, these schists assume more of a chloritic or talcose character, and become more decidedly compound at the foot of the descent. Argillaceous schist is established of a very regular type, though it is found intermixed with the green schists also, which are of a chloritic character.

224. There is another route tending from the Boomot suspension bridge to this point in which the rocks have been examined, and it will be more in place to record the particulars here. This route ascends by the village of Acend, in which the talcose schist observed in the vicinity of the bridge is exchanged for quartz rock, containing, it would appear, nests of indurated talc. At the village, a decided chloritic schist is found. The dip in all the schistose rocks is conformable, but in the quartzose or granular types, the strata are obscure. Between Acend and Jak the same rocks continue with an occasional appearance of brown tender micaceous schist. From Jak to Bendoolee, the transition into the latter is more frequently observable, and it also assumes an argillaceous character. The granitic rock which I have for distinction sake termed greenstone also occurs, forming as usual a transition into the green schist.

225. From the village, the route descends to the bed of the Bendoolee Nullah, the rock being still chloritic schist, verging on argillaceous, and enclosing huge masses of quartz rock, the relations of which to the schist appear very interesting, and deserving of further developement. From what I could observe, it struck me, that these masses were