presses for printing Greek and Latin works in London.

VALTELINE; lordship of Austrian Italy, at the foot of the Alps, now forming the greater part of the province of Sondrio. It is bounded north by the Grisons, and was subject to these till 1797. Square miles, 1270; population, 81,000. This country, called by the Germans Veltlin, or Veltlein, and by the inhabitants Valle Tellina, is a valley, enclosed between two chains of lofty mountains, about fifty miles in length, and from eight to twenty in breadth. It is fruitful, and, throughout its whole extent, watered by the Adda. The whole country is divided into three districts, called Sopra, Mezzo and Sotto, or Upper, Middle and Lower. Tirano is the capital of the first, Sondrio of the second, and Morbegno of the last.

VALUE. The exchangeable value of commodities depends, at any given period, partly on the comparative facility of their production, and partly on the relation of the supply and demand. If any two or more commodities respectively required the same outlay of capital and labor to bring them to market, and if the supply of each were adjusted exactly according to the effectual demand; that is, were they all in sufficient abundance, and no more, to supply the wants of those able and willing to pay the outlay upon them, and the ordinary rate of profit at the time; they would each bring the same price, or be exchanged for the same quantity of any other commodity. But if any single commodity should happen to require less or more capital and labor for its production, while the quantity required to produce the others continued stationary, its value, as compared with them, would, in the first case, fall, and in the second, rise; and, supposing the cost of its production not to vary, its value might be increased by a falling off in the supply, or by an increase of demand, and conversely. But it is of importance to bear in mind, that all variations of price arising from any disproportion in the supply and demand of such commodities as may be freely produced in indefinite quantities, are temporary only; while those that are occasioned by changes in the cost of their production are permanent, at least as much so as the cause in which they originate. A general mourning occasions a transient rise in the price of black cloth; but, supposing that the fashion of wearing black were to continue, its price would not permanently vary; for those who previously manufactured blue and brown

cloths, &c., would henceforth manufacture only black cloth; and, the supply being in this way increased to the same extent as the demand, the price would settle at its old level. When the price of a freely produced commodity rises or falls, such variation may evidently be occasioned either by something affecting the commodity, or by something affecting the value of money. But when, instead of being confined to one, the generality of commodities rise or fall, the fair presumption is, that the change is not in them, but in the money with which they are compared. Exclusive, however, of the commodities now alluded to, there is a considerable class, whose producers or holders enjoy either an absolute or a partial monopoly of the supply. When such is the case, prices depend entirely or principally on the proportion between the supply and demand, and are not liable to be influenced, or only in a secondary degree, by changes in the cost of production. Antique statues and gems; the pictures of the great masters; wines of a peculiar flavor, produced in small quantities, in particular situations; and a few other articles, exist under what may be called absolute monopolies: their supply cannot be increased, and their price must, therefore, depend entirely on the competition of those who may wish to buy them, without being, in the slightest degree, influenced by the cost of their production. Monopolies are sometimes established by law; as when the power to supply the market with a particular article is made over to one individual, or society of individuals, without any limitation of the price at which it may be sold; which, of course, enables those possessed of the monopoly to exact the highest price for it that the competition of the buyers will afford, though such price may exceed the cost of production in any conceivable degree. The rights conveyed by patents sometimes establish a valuable monopoly; for they enable the inventors of improved methods of production to maintain, during the continuance of the patent, the price of the article at a level which may be much higher than is required to afford them the ordinary rate of profit. This advantage, however, by stimulating invention, and exciting to new discoveries, of which it is the natural and appropriate reward, instead of being injurious, is beneficial to the public. (See Patents.) There are also partial monopolies, depending upon situation, connexion, fashion, &c. These, and other inappreciable circumstances, sometimes occasion a difference

of thirty per cent. or more, in the price of the same article, in shops not very distant from each other. The effects on prices produced by the opening of new markets, or new sources of supply, and the effect of war in obstructing the ordinary channels of commercial intercourse, and occasioning extreme fluctuations in the supply and price of commodities, are well known. When a tax is laid on a commodity, its price necessarily rises in a corresponding proportion; for otherwise the producers would not obtain the ordinary rate of profit, and would, of course, withdraw from the business. Speculation has also a great influence on prices. It very rarely happens that either the actual supply of any species of produce in extensive demand, or the intensity of that demand, can be exactly measured. Every transaction in which an individual buys produce in order to sell it again, is, in fact, a speculation. The buyer anticipates that the demand for the article he has purchased will be such, at some future period, either more or less distant, that he will be able to dispose of it with a profit; and the success of the speculation depends, it is evident, on the skill with which he has estimated the circumstances that must determine the future price of the commodity. It follows, therefore, that in all highly commercial countries, where merchants are possessed of large capitals, and where they are left to be guided in the use of them by their own discretion and foresight, the prices of commodities will frequently be very much influenced, not merely by the actual occurrence of changes in the accustomed relation of the supply and demand, but by the anticipation of such changes. It is the business of the merchant to acquaint himself with every circumstance affecting the particular description of commodities in which he deals. He endeavors to obtain, by means of an extensive correspondence, the earliest and most authentic information with respect to every thing that may affect their supply or demand, or the cost of their production; and if he learned that the supply of an article has failed, or that, owing to changes of fashion, or to the opening of new channels of commerce, the demand for it has been increased, he would most likely be disposed to become a buyer, in anticipation of profiting by the rise of price, which, under the circumstances of the case, could hardly fail of taking place; or, if he were a holder of the article, he would refuse to part with it, unless for a higher price than

he would previously have accepted. If the intelligence received by the merchant had been of a contrary description; if, for example, he had learned that the article was now produced with greater facility, or that there was a falling off in the demand for it, caused by a change of fashion, or by the shutting up of some of the markets to which it had previously been admitted, he would have acted differently in this case, he would have anticipated a fall of prices, and would either have declined purchasing the article, except at a reduced rate, or have endeavored to get rid of it, supposing him to be a holder, by offering it at a lower price. In consequence of these operations, the prices of commodities, in different places and periods, are brought comparatively near to equality. All abrupt transitions from scarcity to abundance, and from abundance to scarcity, are avoided; an excess in one case is made to balance a deficiency in another, and the supply is distributed with a degree of steadiness and regularity that could hardly have been deemed attainable. The risk to which merchants are exposed, when they either sell off any commodity at a reduced price, in anticipation of a fall, or buy at an advanced price, in anticipation of a future rise, is a consequence principally of the extreme difficulty of ascertaining with accuracy the grounds on which an abundant or a deficient supply, or an increasing or decreasing demand, may be expected. Rules can here be of no service; every thing depends upon the talent, tact and knowledge of the party. Priority, but, above all, accuracy of intelligence, is, in such cases, of the utmost consequence. Without well authenticated data to go upon, every step taken may only lead to error. The instances, indeed, in which speculations, apparently contrived with the greatest judgment, have ended in bankruptcy and ruin, from a deficiency in this essential requisite, are so very numerous that every one must be acquainted with them. When a few leading merchants purchase in anticipation of an advance, or sell in anticipation of a fall, the speculation is often pushed beyond all reasonable limits, by the operations of those who are influenced by imitation only, and who have never, perhaps, reflected for a moment on the grounds on which a variation of price is anticipated. In speculation, as in most other things, one individual derives confidence from another. One purchases or sells, not because he has any really accurate in

formation as to the state of the demand and supply, but because some one else has done so before him. The original impulse is thus rapidly extended; and even those who are satisfied that a speculation, in anticipation of a rise of prices, is unsafe, and that there will be a recoil, not unfrequently adventure, in the expectation that they shall be able to withdraw before the recoil has begun. It may, we believe, speaking generally, be laid down as a sound practical rule, to avoid having any thing to do with a speculation in which many have already engaged. The competition of the speculators seldom fails speedily to render an adventure that might have been originally safe, extremely hazardous. If a commodity happen to be at an unusually reduced price in any particular market, it will rise the moment that different buyers appear in the field; and supposing, on the other hand, that it is bringing an unusually high price, it will fall, perhaps, far below the cost of production, as soon as supplies begin to be poured in by different merchants. Whatever, therefore, may be the success of those who originate a speculation, those who enter into it at an advanced period are almost sure to lose. To have been preceded by others ought not, in such matters, to inspire confidence on the contrary, it ought, unless there be something special in the case, to induce every considerate person to decline interfering with it. The maintenance of the freedom of intercourse between different countries, and the more general diffusion of sound instruction, seem to be the only means by which those miscalculations, that are often productive of great national as well as private loss, can be either obviated or mitigated. It is superfluous, perhaps, to observe that the precious metals are liable to all the variations of value already alJuded to. Not only, therefore, are prices, as was already remarked, affected by variations in the cost and supply of commodities, but also by changes in the cost and supply of gold and silver, whether arising from the exhaustion of old, or the discovery of new mines, improvements in the art of mining, changes of fashion, &c. Hence it is, that tables of the prices of commodities, extending for a considerable period, communicate far less solid information than is generally supposed, and, unless the necessary allowances be made, may lead to the most unfounded conclusions. The real value of any commodity depends on the quantity of labor required

for its production; but supposing that we were to set about inferring this real value, or the ultimate sacrifice required to obtain the commodity, from its price, it might happen (had the quantity of labor required for its production declined, but in a less degree than the quantity required to produce gold and silver), that its value would appear to rise when it had really diminished. When, however, the rate of wages, as well as the price of commodities, is given upon authentic data, a table of prices is valuable, inasmuch as it shows the extent of the command over the necessaries and conveniences of life, enjoyed by the bulk of the community, during the period through which it extends. Those desirous of detailed information as to the prices of commodities in Great Britain, in distant times, may consult the elaborate tables in the third volume of sir F. M. Eden's work On the Poor; and the fourth volume of Macpherson's Annals of Commerce. Arbuthnot's Tables of Ancient Coins, Weights, Measures, Prices, &c., are well known; but the statements are not much to be depended upon. The Traité de Métrologie of M. Paucton (4to., Paris, 1780) is the best work on this curious and difficult subject.

VAMPIRE. The vampire bat (vespertilio spectrum) is reddish-brown, and about the size of a magpie. It inhabits South America. It has been accused of destroying men and animals by sucking their blood. "But the truth," says Cuvier, in his Regne Animal," appears to be, that it inflicts only small wounds, which may probably become inflammatory and gangrenous from the influence of the climate." It is not altogether improbable that these animals gave origin to the fable of the harpies (q. v.); at least, some ancient authors make mention of these bats. Adelung believes the word vampire to be of Servian origin. The belief in bloodsucking spectres, also called vampires, is very old. The modern Greeks, according to Tournefort's Rélation d'un Voyage du Levant (1st vol., p. 52), call such monsters broucolacas; but even the ancient Greeks had their novσa; and the lamia and lemures of the Romans originated from the same superstition. In 1732, great commotions were caused in Hungary, and particularly in Servia, by the general belief in human vampires, so that investigations were instituted by the government. The common people believed that the bodies of persons who died under sentence of excommunication for sorcery or other crimes, did not decay, but devoured their

The reduction occurs almost instantaneously, with a kind of detonation. The crucible, when cold, is to be put into water, to dissolve the potash, and the reduced vanadium is to be collected on a filter: it is obtained in the state of a black powder, which shines in the sun, and takes a grayish metallic lustre under the burnisher; but this is not the true aspect of the metal. Vanadium is white; and, when its surface is polished, it resembles silver considerably, or molybdenum, which, of all metals, it is most like. It is not ductile, and is easily reduced to a powder of an iron-gray color. It is a good conductor of electricity. The powder of vanadium takes fire at a heat below redness, burns without energy, and leaves a black unfused oxide. Vanadium dissolves readily in nitric acid, and in aqua regia: the solution has a fine blue color. The sulphuric, muriatic and fluoric acids do not attack it at all, even when they are concentrated and boiling. It is not oxidized by the alkaline hydrates, and it may be heated with them to redness without undergoing any alteration, if the air be excluded. The compounds of vanadium and oxygen are three in number:1. Suboxide of vanadium. It is obtained by reducing vanadic, by hydrogen gas, at a red heat, or by fusing vanadic acid in a cavity in charcoal. It has not hitherto been combined with other bodies, or with acids or bases. When heated in the air, it takes fire, and burns, leaving an unfused black residue. It is composed of 89.538 parts of metal, and 10.862 of oxygen.-2. Oxide of vanadium. It is obtained in a state of purity by mixing 9.5 parts of suboxide with 11.5 parts of vanadic acid, and heating the mixture to whiteness in an atmosphere of carbonic acid gas. It is not fusible at the temperature at which glass softens. It is insoluble in water; but if it remains long in it, the water gradually becomes green in consequence of increased oxidation. It dissolves slowly, but completely, in the acids: the solution is blue, and the oxide acts as a base; but it combines with bases, and forms salts, which may be called vanadites. It is composed of 81.056 vanadium, and 18.944 oxygen.-3. Vanadic acid is obtained by exposing vanadate of ammonia to a heat near redness, in an open platina crucible, and stirring it occasionally. The vanadate decomposes, becomes at first black, and afterwards, in proportion as it absorbs atmospheric oxygen, of a red-brown color, which, by cooling, becomes gradually pale, and finishes by turning to a rust color. It is tasteless and inodorous:

it reddens the color of moistened litmus paper. As soon as it is red hot, it fuses. In this state, it sustains a white heat without losing oxygen, if kept from contact with combustible bodies. When fused, it crystallizes on cooling, and then exhibits a phenomenon which merits observation. It solidifies at a heat which is invisible in day-light; but the moment that solidification commences, à luminous circle extends from the periphery to the centre, where, owing to latent heat, becoming free, the mass remains red hot as long as the crystallization continues. The acid contracts much on solidifying, and is readily detached from the crucible: it is then of a yellowish-red color, and formed entirely of a mass of interlaced crystals. It is not a conductor of electricity. It is sligh⚫y soluble in water, to which it imparts a bright yellow color. One thousand parts of boiling water scarcely dissolve one part of acid. The acid is deposited, on evaporation, in the form of red concentric rings. It is easily reduced to the state of an oxide, especially under the influence of an acid. Fused on charcoal by the blow-pipe, it leaves a coherent mass, of the color of plumbago, which is the suboxide: with the phosphate of ammonia and soda, it gives a fine green color to glass, which appears brown while it is hot: with borax, it also gives a green glass. In this reaction, vanadium resembles chromium; but the green color, produced by the former, may be changed to yellow by the oxidating flame, which does not happen with chromium. With carbonate of soda, it is not reduced to the metallic state. It is composed of 74.044 vanadium and 25.955 oxygen. The affinity of vanadium for sulphur is but weak at moderately high temperatures; nevertheless, there are several modes of obtaining sulphurets of vanadium. Hitherto, only two have been formed. The sulphuret consists of 68.02 vanadium and 31.97 sulphur. The supersulphuret is composed of 58.647 vanadium and 41.353 sulphur. When vanadium is heated to redness in an atmosphere of vaporized phosphorus, they do not combine; but when phosphate of vanadium is heated to whiteness in a charcoal crucible, it is reduced, and gives a porous, gray, unfused mass, which may be compressed, and has then the color and lustre of plumbago.-Alloys of vanadium. In experiments upon vanadium, the surface of platina crucibles is often alloyed with vanadium, which does not alter either the color or the metallic lustre of the platina; but when it is afterwards