valleys where nature exhibits her usual aspects.

The primary alluvial land was formed from the first retreat or recession of the lake, and then, it is supposed, the most southern line of fortifications was erected. In process of time, the lake receded further to the north, leaving another section of table land on which the other tier of works was made. The soil on the two flats is very different; the inferior being adapted for grass, and the superior for grain, and the timber varies in a correspondent manner. On the south side of lake Ontario, there are also two alluvial formations; the most recent is north of the ridge road; no forts have been discovered on it. Whether there be any on the primary table land, I have not learnt; south of the mountain ridge many have been observed.

In the geology of our country, it is important to remark, that the two alluvial formations before mentioned, are, generally speaking, characteristic of all the lands bordering on the western waters. While, on the eastern waters, there is but one alluvial tract, with some few exceptions. This may be ascribed to the distance of the St. Lawrence and the Mississippi from the ocean, their having prostrated, at two different periods, impediments or barriers, and in consequence of thus lowering the beds in which they flowed, having produced a partial exhaustion of the remote waters. These distinct formations may be considered as great chronological landmarks. The non-existence of forts on the secondary or primary alluvial formations of lake Ontario is a strong circumstance from which the remote antiquity of those on the highlands to the south may be deduced; because if they had been erected after the first or last retreat of the lake, they would undoubtedly have been made on them as most convenient and best adapted for all military, civil, and domestic purposes.

The Iroquois formerly lived, according to their traditions, on the north side of the lakes. When they migrated to their present country, they extirpated the people who occupied it; and after the European settlement of America, the confederates destroyed the Eries or Cat Indians, who lived on the south side of lake Erie. Whether the nations, which possessed our western country before the Iroquois, had erected those fortifications to

protect them against their invaders, or whether they were made by anterior inhabitants, are mysteries which cannot be penetrated by human sagacity; nor can I pretend to decide whether the Eries or their predecessors raised the works of defence in their territory; but I am persuaded that enough has been said to demonstrate the existence of a vast population, settled in towns, defended by forts, cultivating agriculture, and more advanced in civilization than the nations which have inhabited the same countries since the European discovery.

ART. V. Account of a Portable Gas Lamp.

SIR, London, Nov. 1, 1819. IN the second Number of the Edinburgh Philosophical Journal, I observe an account of what is termed a new portable gas-lamp, invented by David Gordon, esq., of Edinburgh. We are further informed that Mr. Gordon has secured, by patent, the exclusive privilege of this invention. May I beg leave to ask, whether, in the Spring of 1817, you did not exhibit a similar contrivance in your lectures at the Royal Institution, with the observation that, "the size of the lamp, the difficulty of filling it with condensed gas, and its great liability to leak, were only a few of the obstacles to its useful application and adoption."

"Professor Brande,

Your obedient Servant,

M. R. I.

Royal Institution."

In answer to the above, I subjoin a short account of the lamp in question, which is represented in the annexed wood cut; and which, as appears from Mr. Newman's books, was made by him for the Royal Institution at my request, in May, 1816,

December, 1819.

W. T. B.

The lamp consists of a hollow glass globe of adequate thickness, and surmounted by a stopcock and burner, resting upon,

and communicating with, a square hollow pedestal of sheet

copper.

a

a The glass globe fitted with a brass cap at b, firmly screwed into the copper box c, and communicating with it at the aperture d; e is a screw-hole supplied with a valve opening inwards, to which the condensing syringe is attached for the purpose of forcing in the carburetted hydrogen; f is a brass cap surmounted by the stopcock g, of very small bore, opening into the chamber h, to which the burners are attached.

ART. VI. On the Manufacture of British Opium. By the Rev. G. SWAYNE.

FROM the frequent paragraphs which have lately appeared in the public prints on the subject of opium, it should seem that the eyes of the British public are at length beginning to open to the prospect of those advantages which would be likely to accrue to the community, from the introduction of an article of commerce, so much wanted at home, to super

sede the abominably adulterated drug with which the guardians of our health are supplied from the Levant, &c., under that name; and so much in demand abroad, that the last advices from India inform us, that whilst trade in almost all other articles was in an unusually depressed state, the price of opium had risen from 20 to 25 rupees per chest. The introduction, therefore, of the plant which produces the article in question, into the agriculture of this country, discouraged as it is in the production of grain, by the existing system of cornlaws, assumes an interesting and important aspect.

In a late Number of the Edinburgh Journal, a new method is announced of collecting the milky juice of the poppy, from the plausibility of which it is not improbable that several persons in the United Kingdom may be induced to undertake this business. As the specimen of opium which Mr. Professor Brande was so good, upon my request, to submit to the trials of some medical friends last winter, was reported to be excellent, having had the experience of another season, added to that of several former years, to confirm the complete efficiency of the method and apparatus by which that specimen was obtained, I am now ready to communicate the same to the public through the medium of the London Journal of Science and the Arts; and I the rather wish them to be published some time this winter, that those persons who may be induced to engage in the preparation of opium in the ensuing season, from the account which has appeared in the Edinburgh Journal, supposing eventually they may not be satisfied with the method there recommended, may not give up the project in despair; but may have it in their power to make trial of another method, which with me has proved perfectly successful and satisfactory. By means of the method and apparatus above alluded to, half an ounce of liquid opium may generally be collected by one person in less than the space of an hour. And I have it upon record, that on one particular day in the year 1818, a single individual, considerably more than 70 years of age, collected no less than five ounces and a quarter of this fluid within five hours.

The apparatus consists of,

1. A scarifier, or lancet-blade, of a larger size than that used in surgery for venesection, about two inches and ths in length, and ths of an inch in breadth, with a rivethole at the blunt end, through which is inserted a strongly-twisted cotton string; the ends of which having been previously drawn through a small slit in a bit of leather intended as a slide, are to be tied in a firm knot, at a length sufficient, when

slung on the right wrist, and confined to it by the slide, for the blunt end of the lancet-blade to reach the tops of the thumb, and first and second fingers, when united. This blade, if covered with thin leather, excepting about one inch from the point, will be softer and more commodious to the fingers.

2. A small pocket with strings, to be tied round the waist, eight inches wide, ten inches long in the back part, and about five in the fore-part, having two straps of cloth (or leather, which is preferable), five inches in length, and 1 inch in breadth, stitched on its back part in a longitudinal direction, 1 inch apart, for the purpose of forming sheaths to receive the arms of the bracket, to be hereafter described. The ends of the straps to stand of an inch above the back of the pocket. The use of this pocket is to hold any small matters which may be necessary.

3. Two goose-quills of the larger size, cut in the form of scoops; for the purpose of taking off the milky juice from the wounded capsules.

4. A tin cup, or receiver, 24 inches in diameter, and two inches deep, with cover to fit close, in the manner of a saucepan. In the centre of the cover, a circular hole is cut out 14 inch in diameter, into which is soldered a tin tube made to fit the same, 2 inches in length, standing 1 inch above the cover, and entering the cup below of an inch. A circular wire is soldered on round the cup on the outside, to form a groove for the ring of