top of the same hillock are compact, scabrous, and of a slight cellular texture (No. 24). Going on always S. W., we see the same vein continued over the next hill, close to the road going to the Kundas and so much divested of iron, that it resembles a friable stratified sandstone, the quartz being granular (No. 25),

It is in this kind of magnetic iron ore, particularly in the blocks below Gradation Hall, that I remarked on the quartz laminæ, small brilliant, gold-coloured specks, precisely similar to those seen in the auriferous quartz veins in the rocks of the Malabar coasts, specimens of which have been deposited by my friend Colonel CULLEN in your museum. Does this appearance indicate the existence of particles of gold in this ore? We know that in America, gold is occasionally found in the siderocriste, which is a species of quartz iron ore, like the one just described*.

It is the belief of some people, that owing to the similarity of the rocks, of the detritus, and of the quartz veins, of the Malabar coast, and of these hills, gold may be found in this last, as well as in the former. The specimen of the earth I send is taken (No. 26) from an excavation made, some years ago, by an officer, who had been employed on the Malabar coast, for the purpose of ascertaining the existence of gold in the detritus of that coast. It is said that he found gold in the earth dug up on the side of one of the hills of the Dodabetta group, facing the cantonment†.

Before concluding my observations regarding this magnetic iron ore, I must repeat what I said in the beginning; that it is found in thick beds, evidently imbedded either in the original rock, or, which comes to the same thing, in the lithomargic earth, the result of its decomposition.

Iron ores are so common on these hills, independently of the oxides of that metal contained in the minerals forming the rock, that many springs of water are of the chalybeate class.

* The specimen of Colonel CULLEN is marked "auriferous quartz, stratified: Nelli Allum, Malabar." The same gentleman sent to your museum another specimen, which he calls "auriferous micaschist," which contains the same kind of shining, gold-coloured specks.

† The sand which results from the desintegration of this species of iron ore is very nearly similar to what is called titauiferous sand.-Does any menaccanite exist in this sand? The rock in which this ore is contained, appears to be similar to that which is seen in Cornwall, from which the sand containing that new mineral is derived. Professor SEDGWICK informs Mr. DE LA BECHE, that the menaccanite of Cornwall is derived from the decomposition of a hornblende rock, composed of hornblende and felspar.-Geological Manual. BAIKIE'S Observations on the Neilgherries, page 14.

The next species of iron ore on the Neilgherries is the hæmatitic, forming immense beds, and sometimes whole hillocks, among the hornblende rocks, and sienitic granite. In all the places where it is found, large blocks of this ore are seen projecting through the soil, having a scabrous, cellular, and sometimes cavernous appearance at the surface.

As this rock resembles very much the laterite of this part of India, I shall be more particular in describing its geological position and association, in order that it might be seen whether it ought to be classed with the laterite of the low lands, or among the iron ores found in many other parts, associated and in veins, in primitive districts.

Before entering into the description of this rock, I must remark, once for all, that the position and association of the rocks on the Neilgherries is not so easily ascertained, and clearly seen, as in other localities of India, on account of the enormously thick stratum of red earth and vegetable soil, which cover uniformly the whole plateau. So that we are often reduced to the necessity of judging of the nature of the rock composing the hills, by the few projecting masses at the top, or on its declivities.

It is for this reason, that I am unable to say positively whether the rock I am going to describe be overlying, or one of those metalic veins which traverse the original rock; although I have more than one reason to surmise, that the last is the position of this ferruginous ore on the Neilgherries.

All I have been able to ascertain regarding this ore, may be detailed by describing one or two of the localities, where this formation is seen developed in a more marked manner than any where else on the Neilgherries.

The most extensive formation of this hæmalitic iron ore is seen on both sides of what I shall call Scotland Valley*. It is the valley through which the superfluous waters from the lake discharge themselves into the Moyar river. This valley runs nearly E. and W. above two hundred yards below the bund of the lake; close to the left bank of the stream, we see a large block of compact iron ore jutting through the soil (No. 27). Proceeding westward along the right bank of the torrent, for about a quarter of a mile, we come to a place where the stream is joined by another flowing from the S. W. On both sides of this river (until we come to this junction), the projecting rocks,

* Sir FREDERICK ADAM, our present Governor, while on the hills, used to call it by that name, on account of a resemblance he saw in it to some place in Scotland.

which in some places make up knolls and hillocks, are of the usual sienitic granite, with a good deal of hornblende and a few garnets.

On fording the river, at the place of junction, we see on the opposite bank all the projecting rocks to have totally changed their character; they are now cellular, hæmatitic iron ore, rich in metal (No. 28). That rock is seen protruding through the soil of this and of the next hill (W). Some of the enclosures for cattle on the declivities of this hill are constructed with large masses of the cellular iron ore, which however in some of them has a very compact structure (No. 29).

The highest of the two hills appears to be entirely formed of this rock, of which huge masses are seen in the intervening ravine, On the summit of the highest hill, the rock assumes a pudding-stonelike structure, being a hard conglomerate of numerous rounded pieces of ferruginous clay iron ore, strongly agglutinated together by a clayey cement (No. 30). A prodigious number of these rounded pebbles are scattered about, covering nearly the whole of the summit of the hill (No. 31). Many of the hard blocks of this conglomerate resemble very much (if they are not identical with) the laterite of the low lands of India.

Descending from the summit, along the western declivity of the hill (facing Pinnapal Hill), and only a few yards from the top, the rock insensibly changes its appearance and structure. It becomes by degrees more compact, and loses its cellular structure; in short, it assumes the compact appearance of common hæmatitic iron ore (No. 32), very rich in iron; and in this state it continues to the foot of the hill on that side, where some of the projecting masses of this iron ore are flanked by others of sienitic granite, or rather hornblende rock.

These two hills, on the N. E. side, and at their foot, close to the stream, are skirted by immense masses of sienitic granite, through which the waters of the river are heard roaring; except at one place, at the foot of the high hill, where the river is forded to go towards the new road from Nandiwatam to Ootacamund. In that place the iron ore bed crosses the stream; forms numerous projecting masses on the slope of the opposite hill, having a N. E. direction; crosses the road of Nandiwatam, and terminates in the summit of the hillock to the N. E. of the road; beyond the latter place, this rock cannot be traced.

Now this filon of iron ore, after crossing the stream of Scotland Valley, is evidently and clearly seen flanked on both sides by sienitic granite, jutting in large blocks through the soil, in the very same way

as the masses of the iron ore shoot up; and therefore, it is fair to conclude, that the last do not overlie the former.

I must here call the attention of the reader to the almost imperceptible transition of the cavernous tubular kind of ferruginous conglomerate, into the uniformly compact hæmatitic iron ore of this hill: an appearance that I had an opportunity of observing also in the Northern Circars at Pandagaram, near Samalkátah, where the compact, slaty hæmatitic iron ore is seen passing into a conglomerate very much like laterite (Nos. 33 and 34).

Another view of the hæmatitic ore is obtained below the bluff rocks of the summit of Dodabetta, beyond the villages of Mantú, close to the road, which descends from the hollow between Kaití rock and Dodabetta. Coming towards Ootacamund, we see huge masses of ore protruding through the soil (No. 35). It is scabrous and cellular, but not perforated by tubular sinuosities like the laterite. It is similar to some of the masses of the same ore on the declivities of the hills of Scotland Valley. This vein has but a few yards' thickness, having a N. and S. direction. On both sides of, and nearly in contact with the blocks of ore are seen masses of sienitic porphyry, or rather hornblende porphyry, containing some garnets (No. 36), which, as we proceed towards the villages of Mantú, lose the garnets, and become hornblende rock (No. 37).

The two hillocks S. E., and close to the lake, and on which Cluny and South Down houses are built, are chiefly composed of the same iron ore. The sections in these declivities, on account of the road which goes round the lake, show the ore decomposed into a red clayey earth, imbedded in the lithomargic earth, resulting, as we have seen, from the decomposition of the original sienitic rock.

The same ore is seen near the summit of Dodabetta, on the hill before descending into the Elephant Valley, and in other localities, which it would be superfluous to describe, after having detailed the principal features of those places where it most abounds. I must, however, here recall to the memory of the reader what I have said, speaking of the detritus below the vegetable earth. It is in the localities, which abound with this iron ore, that the detritus is composed of ferruginous rounded pebbles, occasionally cemented together into a hard conglomerate, like oolitic iron ore, by a clayey paste.

The hæmatitic iron ore seems to contain some felspar, which in this rock is decomposed into a yellowish clay, lining some of the cavities in the rock but I never found any quartz in it.

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Before concluding these details regarding this iron ore, I will point out some particularities, in which (notwithstanding its similarity in

appearance) it seems to differ from the laterite of the other parts of India, that I have had an opportunity of examining. The rock of the Neilgherries is by no means so cavernous, and has not so many tubular sinuosities as the laterite of the Carnatic, Northern Circars, &c.; it seems also to be richer in metal, and, what appears to constitute a marked difference, it is entirely divested of any quartz, or sandy particles, which abound so much in the laterite of other places. Besides, we are told by Doctor HEYNE, that in the laterite of the Red Hills, Nellore, &c. a marl or carbonate of lime is occasionally one of the ingredients; no traces of this carbonate are found in the stone of the Neilgherries*.

That this rock of the Neilgherries is to be classed with hæmatitic iron ore, rather than with the true Indian laterite (an overlying rock), is very probable, considering that rocks similar in appearance to it are found in Europe, while the last is peculiar to India†.

It is said of the Indian laterite, that it is associated occasionally with trap. On the Neilgherries, basaltic dykes are not rare, yet I never saw what VOYSEY remarked in other parts of India, viz. the passage of basalt into wacke, and into iron clay, (by this last name, meaning laterite ;) another additional difference between the two rocks.

Hitherto no organic remains have been found in this rock on the Neilgherries, which appears also to have been the case with the laterite of the other parts of the peninsula.

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I am not positive regarding the existence of manganese on these hills my friend Colonel CULLEN says, that it is found mixed in the iron ore near the lake; and I found a straggling piece of this ore in the valley of Kaití (No. 38), which I have not analysed, but which has all the external characters of one.

The lowest visible rock of the Neilgherries is of the primitive unstratified class, including true granite, pegmatite, sienitic granite, and hornblende rock: sienitic gneiss, and hornblende slate are occasionally seen, but they belong more to the outskirts of the hills than to the group itself. Besides these rocks, we find granitelle, and a rock composed of four minerals, felspar, hornblende, garnets, and quartz.

True granite, composed of felspar, quartz and mica, is not of rare occurrence; it frequently occupies the summits of the highest hills: thus it is seen in some of the Kundá range, and of the Dodabetta group;

*Tracts.

If my memory serves me right, I think I saw in your museum a specimen marked "black, brown, solid and perforated iron ore, from Poetz in Upper Lusatia," which appears to me similar to the Neilgherries hæmatitic, cavernous iron ore. No. 38 is decidedly an ore of manganese.-ED.