to produce instruments for every other purpose in the fields of culture equally superior; it may not be irrele vant to observe, that trivial means (seeing, from thirty years close attention to the subject, it has been clearly ascertained they produce no end whatever) have certainly been tried long enough; and however grating it may be to some, not having been accustomed to ruminate thereon, to hear, it is equally certain that doing things for no end, if not as wise, is certainly as idle, and even more childish than doing nothing at all; whilst, with regard to the consequences of so passing through life, it might be going out of the proper line of the writer to descant on them. He hopes, however, that he may be allowed to observe, that had it never been permitted to back horses on the turf with more than five hundred farthings, we should not at this time have it in our power to breakfast at Bath, and sup in London, but preparatorily, as formerly, making our wills, have been content to take chances therein for life or death in a four or five days journey.

TO BE CONTINUED IN OUR NEXT.

On

On two new Metals, one of them a fixed Alkali, the other a Metallic acidifiable Base. In a Letter from Professor BERZELIUS to M. BERTHOLLET. Feb. 1818.

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From LES ANNALES DE CHIMIE ET DE PHYSIQUE.

HAVE delayed answering your obliging letter, in order to be able to communicate to you the results of some interesting researches made in our favourite science. I have this time to inform you of the discovery of a new metallic substance, the oxyd of which is a fixed alkali; and of another acidifiable metallic substance more analogous to sulphur than to any other body.

The new alkali was discovered by M. Arfredson, a very skilful young chemist, who for this last year has been employed in my laboratory. He has found this alkali in a mineral discovered by M. Andrada in the mine of Uto, and called by him petalite. This mineral consists of about eighty per cent. of silex, seventeen of alumine, and three of the new alkali. To extract the alkali, M. Arfredson employs the common method of calcining the pulverised stone with carbonate of barytes, and afterwards separating all the earthy contents.

The chief characters of this alkali are the following: most of the salts which it forms with acids are very fusible, the sulphate and muriate melt long before they are heated to redness. The carbonate fuses when just red, and then acts on platina almost as actively as the nitrate of any other alkali. The sulphate crystallises pretty readily, and holds no water of crystallization. Its solution is not precipitated either by muriate of platina or tartaric acid. The muriate of this new alkali is extremely deliquescent, more so even than muriate of lime. The nitrate forms rhombic crystals which are very greedy of VOL. XXXIV.-SECOND SERIES. R moisture.

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moisture.

The carbonate dissolves in water with difficulty, the solution gives by evaporation very small prismatic crystals. This alkali has a greater capacity of saturating acids than any other fixed alkali, even than magnesia; and it is from this circumstance that it was discovered, its neutral salt obtained in the analysis being found to weigh much more than it would have done had the alkaline base been potash or soda. It was naturally supposed by the discoverer, that a salt with an alkaline basis which was not precipitated by tartaric acid must be a salt of soda; but having three times repeated the analysis of petalite with the same results, and examined each constituent separately, he found that the alkali had properties different from any already known. We have given it the name of Lithion, to call to mind its origin from the mineral kingdom, whilst the other fixed alkalies which in Sweden we call Kali and Natron, shew by their names their vegetable origin.

The new acidifiable metal was discovered in the following manners in a sulphuric acid manufactory at Fahlun (in which M. Gahn and myself have purchased a share), where the mode of acidifying the sulphur is somewhat different from that practised in England, sulphur obtained from the Fahlun pyrites is burned, during which a reddish sulphureous mass is deposited on the floor of the Teaden chamber. In examining this mass, we found that it burned with a very strong smell of horse-radish, which made us suspect the presence of sulphuret of tellurium, but we could not extract a particle of this latter metal from it. I then took a quantity of it to Stockholm to examine it more accurately. I found that this red sulphureous mass contained a very volatile easily reducible foreign substance, which was not precipitated by alkalies, and I succeeded at last in obtaining it separate.

The

-The characters that I have hitherto discovered in it. are the following: its colour in mass is grey, with a very › strong metallic lustre ; its fracture is vitreous like sulphur, or like the fahlerz, which it also resembles in colour, but with more lustre; its specific gravity is about 4.6; it is hard, but very friable like sulphur. When triturated, it falls into a red powder, with streaks of a metallic lustre, like the other brittle metals. It softens at the heat, of boiling water; and at a little higher heat, melts. It remains semi-fluid while cooling, like sulphur or Spanish, wax, so that it can be moulded between the fingers, or pulled out into small threads having a bright metallic lustre, but which appear quite transparent and red, when held up to the light. When heated further it boils, and distils in opake metallic drops. During the sublimation, the retort is filled with a gas of a less deep yellow than gasiform sulphur. If it is distilled in a large necked retort, it sublimes in flowers of a fine vermillion red, which, however, are not the metallic substance oxydated, for they return to the original grey metallic appearance sim ply by melting again in a mass. These red flowers, when sublimed without taking fire, have no peculiar smell: but on the other hand, if the flame of a candle or of a blow-pipe is directed against the sublimed vapour, the flame becomes of a fine azure blue, and gives out so strong a horse-radish smell, that one-fiftieth of a grain thus evaporated is sufficient to scent a large room, Klaproth asserts that tellurium gives the same odour. However, neither pure tellurium, nor its oxyds, nor its, alloys with other metals, produce this odour. I have only been able to produce it by enclosing a piece of purified tellurium in a small globule of glass, and directing the flame of the blow-pipe on it till the vaporised metal has burst a hole in the softened glass. The smell was then exactly

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like

like that of this new metal, but I shall not decide whether it belongs to them both, or to the new metal accompanying the tellurium. However, to mark this affinity with tellurium, I have called this new metal selenium.

Selenium combines with metals, and often produces with them a bright ignition. The seleniuret of potassium forms a greyish-white metallic button, which dissolves in water rapidly, and with effervescence, giving it the colour of strong beer, and the exact taste of sulphurer of potash. Acids disengage from this alloy a gas, whose smell, when diluted, might be mistaken for that of sulphuretted hydrogen; but when snuffed up the nostrils, even in very small quantities, gives a considerable pain, followed by catarrhal inflammation. The hydroseleni-2 uret of potash, dissolved in water, becomes covered with a skin, at first of a vermillion red, which becomes grey: as it thickens. Mixed with muriatic acid the liquor becomes turbid, and deposits a red powder, which shews. that the selenium in the solution is in excess, as happens with the sulphuretted hydrosulphurets. Selenium dissolves in the fixed alkalies both by fusion and watery solution. These compounds are vermillion-red, as well as those made by fusión with barytes and lime, but these latter are insoluble. Selenium also dissolves in the fat oils, giving them the same red colour: These solutions have not the hepatic smell of those with sulphur. ›

Nitric acid, assisted by heat, dissolves selenium. The solution, evaporated in a retort, gives a salt which crystallises, and easily sublimes in needles, often an inch long. The sublimate is very soluble, both in water and alcohol. Its taste is simply acid; it reddens litmus, and gives distinct salts with the alkalies. It is, therefore, an acid, whose base 'is selenium. The alkaline seleniates crystallise with difficulty, and attract the moisture of the