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cates that the high ground actually met, in some former period; that the valley was originally a lake; and that its water was discharged by a waterfall. There is so much resemblance between the bed of Long Lake and some of these places which I have examined, that I cannot doubt the correctness of this opinion. Had the waters of that lake been discharged two centuries earlier, its bed, and the gulley which it formed, would have been filled with a thrifty forest; and the evidence that it had ever been a lake would have been no more satisfactory than we now possess, that the places to which I have alluded were once filled with water. We now know the fact, however, that lakes may be suddenly and finally emptied, and their beds changed to fertile valleys, so as to lose, in no great length of time, all traces of the immediate action of water.

Several individuals, well acquainted with the country, informed me that the ground at one extremity of Lake Willoughby, which lies a few miles east of Barton, is formed like that at the northern extremity of Long Lake; and that its waters could be discharged with even less labour, than were those of the latter. Lake Willoughby is about seven miles long, about three miles wide in the broadest part, and very deep; and its waters, if thus discharged, must flow south-eastward, through the valley of the Presumpsick, into the Connecticut. Could the discharge be achieved without too much hazard, it would be an incalculable advantage to a large extent of country; as a long range of towns in the neighbourhood of this lake, are separated from the Connecticut by a chain of pathless mountains, through which no road can be formed, except over the emptied bed of Lake Willoughby, and are thus compelled to find their market down the valley of the Presumpsick; a fact which has almost entirely prevented their settlement.

After we had examined the bed of Long Lake, and the ravages

which its waters had occasioned, as long and as minutely as our time would permit, we returned down the gulley, and arrived at our inn at 3 o'clock, where we sat down to a meal rendered welcome by laborious exercise and the fasting of 'ten hours. Immediately after, bidding four of my companions adieu, I rode down the river in company with the fifth, to the village of Barton. Our course was on the eastern bank of the gulley, and every step of the way I could witness the desolation of the torrent. Taking the whole excavation for the twelve miles in which I followed it, it is the highest exhibition of the effects of physical force, instantaneously exerted, which I have yet seen.

See Plate III. for a Plan of the Lakes, illustrative of the details above given.

Overland Arctic Expedition. As any notice, however short, of the scientific doings of this enterprise, cannot fail to prove acceptable, we now add the following details to those already communicated.

“ FORT FRANKLIN, GREAT BEAR LAKE,

February 6. 1826. Nothing of any importance has occurred since I wrote you last, except that we have received a friendly message from the Esquimaux, through the Sharp Eyes, a neighbouring tribe, who frequent Fort Good Hope, the most northerly of the Company's posts. On the 29th of November last, the S. W. quarter of the sky was cloudless, but of a pure emerald-green colour, (compared at the moment with Syme's book), soon fading away into mountain-green. The rays of the sun setting to the S.S.E. at the same time tinged some clouds gold-yellow, &c. The aurora has not been so frequent, and our observations of course upon it are not so interesting, as at Fort Enterprise As far as they go, they confirm the few general remarks then hazarded, although I think not favourable, in general, to Hansteen's theory. With regard to facts, Captain Franklin's observations and Hansteen's seem to agree. The Edinburgh Philosophical Journal for March 1825 reached us last month, and has proved a great treat to us. I am glad to see it go on so vigorously.

“We expect, if every thing prospers with us, and at present we have no reason to fear any misadventure, that we shall reach England early in November 1827. This is rather too quick a movement for the purposes of science. Even a cursory view of the geology of the Rocky Mountains skirting Mackenzie's River

OCTOBER-DECEMBER 1826.

L

might occupy some months very pleasantly; but the delay of a few days here is the loss of a season, and we cannot reckon on more than two months in the year for such purposes.”

“ Fort FRANKLIN, GREAT BEAR LAKE,

March 23. 1826. “ MY DEAR SJR, “ In consequence of an imperfect, but very interesting, Indian report of Captain Parry's wintering on the coast, and which Captain Franklin is desirous of investigating, I have another opportunity of writing to you this season. The particulars of the report, when ascertained, will be transmitted to Mr Barrow, from whom you may get them.

“ I mentioned, in a former letter, that a formation of lignite occurs in this quarter. The lignite has a slaty structure, thinnish, or only moderately thick; and, when exposed to the atmo sphere, cracks into forms generally nearly rectangular. Some portions, which are rather thick slaty, with a flat conchoidal fracture in the small, bear a very near resemblance to the slaggy mineral pitch or bitumen so common in the limestone forma tion of Slave River (zechstein ?). It is distinguished from it when put in the fire.

« In the more common form of the lignite, the surface of the slates is more dull and earthy, of a brownish-black colour, but yielding a shining streak. These slates are entirely composed of fragments, having all the appearance of charred wood united together by a paste of more comminuted woody matter, mixed perhaps with a minute portion of clay. In the paste, there are some minute perfectly transparent crystals, having the form of compressed four sided prisms, and sometimes of tables. The fibrous structure of the woody fragments is fine, and the lustre resembles that of fresh well-made charcoal of brick. The structure is evidently exogenous.

The fragments are generally small, but, when several inches in diameter, their layers of structure are waved and curved, as if they had been knots, which of course would not so easily break down as the other portions. One of my specimens ,shews a small grain, either of resin or of amber; and I have picked out of another a membranous substance, which has all the appearance of a portion of Ulva montana (Bot. App. Franklin's Journey) common

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here at the present time. I inclose this minute specimen, which has already suffered some diminution in the course of my examination of it. Muriatic acid produced no change in it; but I was afraid to try the nitric acid, lest it should destroy it.

« When put into the fire the lignite burns without flame, and emits a very disagreeable stench, unlike that of either peat or of sulphur. The combustion does not cease when the coal is removed from the fire, but goes on slowly, until there is only a brownish-red ash remaining, not one-tenth of the original bulk of the specimen.

“ The beds of lignite lie on the east side of Bear Lake River, where it joins the Mackenzie, are in the aggregate six or seven yards thick, and are covered by a thick bed of loose sand. They were on fire when Sir A. Mackenzie discovered the river (in 1789), and have continued burning ever since. At the distance of a few hundred yards up the Bear Lake River, there are some thick beds of a coarse, bluish-grey, earthy looking sandstone (very like that on the north side of the Calton Hill), dip.. ping at a small angle under the lignite. They were not seen in actual contact. On the opposite side of Bear Lake River, which is 200 yards wide, a craggy hill of (carboniferous ?) limestone rises abruptly to the elevation of 400 feet. About 30 miles farther up Bear Lake River, and nearly east from its mouth, the stream cuts the base of another limestone hill, of similar form and heights belonging to a chain of (partly transition ?) hills, which runs N.W. and S. E. through a flat country. At the foot of the nearly vertical limestone, but separated from it by a small rivulet, there are thick horizontal beds of sandstone, resembling that at the mouth of Bear Lake River. Upon this sandstone lie a number of thin beds of bituminous shale and sandstone, which weather easily. In the shale there are impressions of ferns (polypodiaceæ), and in the slaty sandstone lepidodendra ? I have had no opportunity of examining these rocks, excepting very cursorily, as we passed them in the boat, and occasionally snatched a specimen; but I. purpose, if the snow disappears long enough before the opening of the navigation, to visit them carefully this spring. The finest sections on the banks of the river will be hid by accumulations of ice till the autumn."

On the Luminousness observed in the Eyes of Human Beings,

and also in those of Cats, Dogs, Horses, and Sheep, By Dr CHARLES LUDWIG ESSER *.

APPEARANCES

PPEARANCES of light, as is well known, are not uncommon in inferior animals, and the number of luminous animals in the sea is so great, that large tracts of the water's surface have been seen to be illuminated by them.

This phenomenon, however, is comparatively seldom observed in fishes, and the more rarely the higher we ascend in the scale of the animal kingdom, if under the denomination of luminousness, we understand the real evolution of light, and do not consider it as the reflection of the incident rays of light; for in this latter case the luminous appearance does not inhere in the animal body itself, but is in reality merely a reflection, which is totally different from the evolution of light in the inferior animals. A real phosphorescence is sometimes observed in the higher animals, and even in human beings, particularly in their excrementitious fluids. The light of the eggs of the lizard, the luminousness of the perspired matter in man and horses, the irradiation of light in cats and other animals, from the stroking of their hair, and finally the phosphorescent quality of human urine, have been frequently observed.

On most of these various kinds of light, I have neither performed experiments myself, nor have I collected the facts of others; the present memoir being chiefly devoted to an examination of the light or luminousness of the eyes in human beings and inferior animals.

The more perfectly to accomplish this object, I some years ago performed a series of experiments, that led to an important result.

Having brought a cat into a room half darkened, I observed that the eyes of the animal when opposite the window, and in a certain direction to myself, sparkled very brilliantly, which phenomenon suddenly vanished, when I, either by the motion of my head, changed the direction of my eyes to those of the cat, or the

* Karsten's Archiv, b. viii. heft iv.

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