before mentioned, and a man that he had heard of, were both dead; and since gentian is of general use in medical compositions, as well as the primary ingredient in the cordial bitters ladies make for their own use.

Of Large Subterraneous Caverns in the Chalk Hills near Norwich. By Mr. Wm. Arderon, F.R.S. N° 486, p. 244.

About a quarter of a mile from the city of Norwich, on the east side, and near the entrance of Moushold-heath, is a large subterraneous cavern, which has been formed in a long series of time, by digging out chalk for making lime. There is only one entrance into it, about 2 yards wide, and nearly the same height; however the height gradually, rises, till at last it measures in some places from 12 to 14 yards. But though the entrance is so small, the whole area within is of such a large extent, that 20,000 men might with great ease be placed in it, and from the entrance to the farthest part of these cells, measures full 400 yards; and these passages are often 10 or 12 yards wide, with branchings out on the sides, into various lanes and labyrinth-kind of windings, which every now and then open into each other; which renders it no easy task to find the way out, when a person has been a little bewildered in these subterraneous mazes,

Most of these vaults are arched at top, by which the immense weight above is well supported; a weight no less than that of hills, whose perpendicular altitude above the tops of these arches is 20 or 30 yards, if not much more.

How deep or thick these rocks of chalk are, no one can tell; for in sinking the lowest wells, they have never been dug through; and consequently must be exceedingly deep. The chalk at the farther end of this cavern is so very soft, that it may be moulded with the hand like paste; which is probably its original consistence, and what it always retains, till it becomes exposed to the air. In the very lowest parts of these vaults Mr. A. has picked up several kinds of fossils, figured by marine bodies; such as echini, pectunculi, common or fluted cockle, belemnitæ, &c. Sounds made beneath these arched roofs are strongly reflected from side to side; so that the least whisper may be heard at a considerable distance. The beat of a pocket-watch was heard distinctly full 20 yards from where it was placed.

He visited this place on the 1st day of November last, to try the temperature as to heat and cold; and carried with him a thermometer regulated by one of Mr. Hauksbee's, which he set down at the farther end of these caverns; and letting it remain there for some time, he found the mercury rested at 52°; which comparing with the register he had kept, was within half a degree of a medium between the greatest heat and the sharpest cold known in that city for 10 years. past; and it is very probable, if the 2 extremes had been taken more exactly, the temperature in these caverns would be found to come yet nearer to the me

dium of heat and cold in this climate; which is also within 1 degree of the temperature recorded of the cave at the Paris observatory.

At the foot of a high hill, adjacent to these vaults, issues out a curious spring, the water of which he found exactly of the same temperature with that underground; though, when the thermometer was exposed to the open air, it stood at 57°.

N. B. A terrible thunder storm, June 12, 1748, shook the earth to such a degree, as to throw down those chalk vaults.

Some Observations and Experiments made in Siberia, extracted from the Preface to the Flora Siberica, sive Historia Plantarum Siberiæ cum tabulis æri incisis. Auct. D. Gmelin. Chem. et Hist. Nat. Prof. Petropoli 1747, 4to. Vol. 1. By John Fothergill, M. D. Lic. Colleg. Med. Londin. N° 486, p. 248.

By direction of the late Empress of Russia, several members of the Royal Academy of Sciences at Petersburg undertook a journey into Siberia, in order to inquire into the natural history of that country, and to make such experiments and observations, as might tend to give a just idea of that almost unknown region, and to the improvement of physics in general.

Dr. John George Gmelin, professor of chemistry and natural history at Petersburg, was placed at the head of this deputation, who, besides several of his colleagues, and some students, had a painter or two, a miner, a huntsman, and proper attendants in his retinue. They set out on this expedition im August 1733, and returned to Petersburg in Feb. 1742, after having spent near 9 years in visiting almost every part of Siberia.

The fruits of this undertaking are designed to be communicated to the public,* and one volume of the history of plants has already appeared, entitled as above. This is intended to be followed by several others, containing not only a descrip tion of the plants, their locus natalis, &c, but their uses among the inhabitants, so far as the Professor could get information concerning them.

In a large preface to this first volume, the ingenious and indefatigable author has given a concise account of Siberia in general, its rivers, lakes, mountains, mines, the nature of the soil, fertility, &c. with several judicious experiments and remarks on the altitude of the earth above the level of the sea; but espe cially on the qualities of the air in that climate.

Pauda is allowed to be the highest of all that ridge of mountains, called Wer

Professor Gmelin's travels in Siberia were published in the German language, in 4 vols. 4to. Many and very important additions, relative to the geography and natural history of Siberia, were afterwards made by the late professor Pallas.

+ Three more vols. of this splendid work were afterwards published; a further account of which will be found in the 48th vol. of the Philos. Trans.

3

koturian. Our author endeavoured to take the height of it by means of the barometer. Dec. 11, 1742, at his lodgings at the foot of Pauda, the mercury in the barometer, in a cold place, but within doors, stood at 26, Paris measure. He then carried it up the mountain as high as he could go, which was about one-third of the whole height, where he hung up the barometer on a tree, from 9 to 11 in the forenoon, making a good fire pretty near it, lest the intense cold, which sunk the quicksilver in De Lisle's thermometer to 201, should affect the barometer, and lead him to ascribe that to gravity, which was only owing to the contraction of cold. Under these circumstances the quicksilver sunk to 25. Hence, according to Cassini's calculation, the first station will be 941 feet higher than the level of the sea: the second on Pauda 1505 feet, and the whole height of this mountain 4515, or 752 Paris toises; which, added to 941 feet, the height of his lodgings at the foot of Pauda, makes 5456 feet, or 909 toises, the height of Pauda's top above the sea; supposing the level of the sea to be 28 inches, as the Paris academicians have fixed it; though this differs from observations made on the barometer at the sea-coast of Kamschatka at Bolcheretz, where, from experiments made for above 2 years, the mean height of the mercury was 27 inches, 6 lines; and at Ochotz, during a year's observation, the mean height was found to be 27 inches and about 84 lines. Hence it would appear, that the sea of Kamtschatka is higher, with respect to the earth's centre, than the ocean and Mediterranean; and at Bolcheretz higher than at Ochotski.

The author finds that the plains in some parts beyond the lake Baical, are almost as high as the tops of high mountains in some other countries; mount Massane, according to the French geometricians, being but about 408 toises high, which differs but little from the plain country at Kiachta; which yet has considerable mountains rising in its neighbourhood. Whence our author concludes, that the elevation of the earth, in this tract, above the level of the sea, is very great, compared with the west part of Siberia and Europe.*

The coldness of the air of Siberia is the most remarkable quality. In some places it snows frequently in September, and not seldom in May; in Jacutsk, if

* M. De la Condamine, in his voyage through the inland part of South America, makes Quito to be between 14 and 1500 toises above the level of the sea. Suppose

He tells us, that Pichincha is 750 higher..

This makes in the whole.

above the level of the sea.

...

1450
750

2200 toises

P. Martel, engineer, in his account of the Glacieres in Savoy, printed at London 1742, tells us, that the barometer at Geneva, by the side of the Rhone, stood at 27 I. which is 656 feet above the level of the sea, according to Scheuzer; and that the highest point of Mont Blanc, measured partly by the barometer, and where inaccessible from the snow that covers it, by trigonometrical operations, is 12459 feet, or somewhat more than 2076 toises above the level of the Rhone; which, added to the height of this above the sea, makes 13115 French feet, or about 2 English miles and two-thirds.

the corn be not ready to cut in August, which often is the case, the snow sometimes prevents it, and buries the harvest all together. At Jacutsk the Professor ordered a hole to be dug in the earth, in a high open place, on the 18th of June, the mould was 11 inches deep, below that was sand about 24 feet; it then began to feel hard, and in half a foot more it was frozen as hard as possible. In a lower place, at no great distance from this, he ordered another hole to be dug: the soil was 10 inches; soft sand 2 feet 4 inches; below this, all was congealed. So that the earth is scarcely thawed, even in summer, above 4 feet deep.

Our author inclines to the received opinion, that the eastern climates under the same latitude are colder than the western; and thinks this is confirmed by experiments made in different parts of Siberia. The mercury in De Lisle's thermometer often sunk in winter in very southern parts of this country, as near Selinga, to near 226, which is equal to 554 below 0 in Fahrenheit's thermometer. But the cold is often much more intense than this, as appears by the following experiments, made at Kirenginski.

Feb. 10, 1738, at 8 in the morning, the mercury stood at 240 degrees in De Lisle; which is 72 below 0 in Fahrenheit's. On the 20th it sunk one degree. At the same place in 1736, Dec. 11, at 3 in the afternoon, 254 in De Lisle. Almost 90 below O in Fahrenheit.

Dec. 20, 4 o'clock p. m. 263 in De Lisle, or 99

below 0 in Fahrenheit.

· 270D = 10773F below 0.

275 = 113%.

260.

280 = 120.

250 and rose by degrees till 11

Such an excess of cold could scarcely have been supposed to exist, had not experiments, made with the greatest exactness, demonstrated its reality. During this extreme frost at Jenisea, the magpies and sparrows dropped down as they flew, and to all appearance dead; though they mostly recovered when brought into a warm room. This was quite new to the inhabitants of that country; though it frequently happens in Germany in much less intense cold, when the weather sets in at once very severe. The air, says the author, was at that time extremely unpleasant; it seemed as if itself was frozen, being dark and hazy; and it was scarcely possible even to bear the cold in the door way for 3 or 4 minutes.

But the utmost limits of cold are yet unknown; or to what degree an animal can subsisi in it when gradually inured to it. The history of heat is alike imperfect. Boerhaave thought, that a man could not bear, without the utmost danger, a greater heat than that which would raise the mercury to 90 in Fah

renheit's; but an ingenious and accurate correspondent of the author's at Astrachan informs him, that it not only rises there to this degree frequently, but even to 100, and he has seen it 1034. Even in the bagnios in Russia, the heat is often equal to 100; it sometimes makes the quicksilver ascend to 108, 110, and to 116; and yet people not only bear them with impunity a few minutes, but often stay half an hour or an hour. [On this subject, see Dr. G. Fordyce's experiments, Phil. Trans, vol. 77.]

By John Henry From the Latin.

It carries off with

A New Discovery of the Usefulness of Electricity in Medicine. Winkler, Prof. at Leipsic, and F. R, S. N° 486, p. 262. Electricity has the property of dividing bodies very subtilly. it the parts of those bodies it dissolves, to those places where the electric sparks appear. If odorous substances be ever so closely confined in glass vessels, it so divides them, that their exhalations penetrate the glass as easily as magnetism, and flow like a river through the atmosphere of cylinders and chains. The electric matter that issues from the other extremity of the cylinder, gives an aromatic odour to the hand that touches it. Yet the odour communicated does not stop in that part of the body on which the electrical stream has flowed, but with a continued aspiration pervades the whole human frame. Not only are the skin and garments scented, but even the very air breathed by the lungs, the spittle, and the sweat of the person, smell of the aromatics, which are agitated by electricity in the closed vessel.

All this has been proved by several experiments that have been carefully made. In 1747 Mr. W. filled a glass vessel with water, and dissolved nitre in it. After standing some weeks, the water became very clear, by the heavier parts subsiding. At the latter end of the year he put a wire into this clear water, and joined it to a metal tube suspended on silken threads. He put under this tube sometimes metals, sometimes metallic vessels full of water, in which were glass spheres filled with metalline particles. Then he excited the electricity, the electrical fire touching the bodies underneath, and he repeated the electricity several days. He then found a great quantity of nitrous parts in the metals and vessels, which had been touched by the electric fire under the metal tube. Other vessels, that were placed in the room where the experiments were made, but not touched by the electric matter from the tube, showed no traces of the nitre. Hence it appears that the parts of the nitre are taken out of water by electricity, and conveyed to places touched by the electric fire.

This conjecture was greatly confirmed the same year by a publication in Italy, by Sig. Jo. Franc. Pivati, on medical electricity; in which a manifest instance of the virtue of electricity was shown on the balsam of Peru; which was so concealed in a glass cylinder that, before the application of electricity, not the least