778 



VAMPIREVANADIUM. 



in the field ; and supposing, on the other hand, t hat 

 it is bringing an unusually high price, it will full, 

 perhaps, far below the cost of production, as soon 

 as supplies begin to be poured in by different 

 merchants. Whatever, therefore, may be the suc- 

 cess 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 per- 

 son to decline interfering with it. The mainte- 

 nance 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 alluded to. Not 

 only, therefore, are prices, as was already remarked, 

 affected by variations in the cost and supply of com- 

 modities, but also by changes in the cost and supply 

 of gold and silver, whether arising from the ex- 

 haustion 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 gen- 

 erally supposed, and, unless the necessary allow- 

 ances be made, may lead to the most unfounded 

 conclusions. The real value of any commodity 

 depends on the quantity of labour required for its 

 production; but supposing that we were to set 

 about inferring this real value, or the ultimate sac- 

 rifice required to obtain the commodity, from its 

 price, it might happen (had the quantity of labour 

 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 commodi- 

 ties, is given upon authentic data, a table of prices 

 is valuable, inasmuch as it shows the extent of the 

 command of 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 commo- 

 dities in Great Britain, iti distant times, may con- 

 sult 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. Ar- 

 buthnot's Tables of Ancient Coins, Weights, Mea- 

 sures, Prices, -c., are well known ; but the state- 

 ments are not much to be depended upon. The 

 Traite de Metrologie of M. Paucton (4to., Paris, 

 1780) is the best work on this curious and difficult 

 subject. 



VAMPIRE. The vampire bat (vespertilio spec- 

 trum) 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 

 Rcgne Animal, " appears to be, that it inflicts only 

 small wounds, which may probably become inflam- 

 matory and gangrenous from the influence of the 

 climate." It is not altogether improbable that 

 these animals gave origin to the fable of the harpies ; 

 at least, some ancient authors make mention of 

 these bats. Adelung believes the word vampire to 

 be of Servian origin. The belief in blood-sucking 

 spectres, also called vampires, is very old. The 



modern Greeks, according to Tournefort's Relation 

 d'un Voyage du Levant (1st vol., p. 52), call such 

 monsters l/roucolacas ; but even the ancient Greeks 

 had their i^<ri/<r<; and the lamiee and lemures of 

 the Romans originat-ed 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 insti- 

 tuted 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 own 

 flesh, and, during the night, left their graves, mid 

 sucked the blood of persons with whom they had 

 been connected, so as to kill them. 



VAN ; a Dutch preposition. See Von. 



VAN DER VELDE, ADKIAN, WILLIAM, and 

 CHARLES. See Velde. 



VAN DIEMEN'S LAND. See Diemen's Land. 



VAN EYCK. SeeEyck. 



VAN SPEYK, JOHN CHARLES JOSEPH, born in 

 1802 or 1803, in Amsterdam, lost his parents early, 

 was educated in an orphan asylum, and learned a 

 mechanic's trade, which he soon quitted to enter 

 the navy. He distinguished himself in the battle 

 at Palembang, and was made a lieutenant. Feb. 5, 

 1831, he was in command of a gun-boat at the siege 

 of Antwerp. Being driven by the wind up to the 

 city, he was attacked by the Belgians, notwith- 

 standing an armistice then existed. Upon their com- 

 ing on deck and insulting the Dutch flag, in spite of 

 his repeated warning that he should blow them up, 

 he went below, and was shortly after found, by 

 one of the crew, in the attitude of prayer. He 

 told the man that the crew must take care of them- 

 selves, and, after a brief space, fired a pistol into 

 the powder magazine, containing about 1500 pounds 

 of powder, and blew up the vessel. Four of the 

 crew, consisting of thirty-one, were saved : all the 

 rest, with the Belgians, about forty on board, 

 perished. The king of the Netherlands ordered 

 that there should be always a vessel in the Dutch 

 navy bearing the name of Van Speyk. 



VAN SWIETEN. See Swieten, Van. 



VANADIUM ; the name of a newly-discovered 

 metal. It was first found in a lead mine at Zima- 

 pan, in Mexico, in the year 1801, by Del Rio, who 

 announced it as a new metal, under the name of ery- 

 thronium but the same mineral having soon after- 

 wards been examined by Collet Descotils, he as- 

 serted that erythronium was merely impure chro- 

 mium. Del Rio himself adopted the opinion of the 

 French chemist, and considered the mineral as a 

 subchromate of lead. In the year 1830, Sefstrom 

 discovered this substance in a Swedish iron, re- 

 markable for its ductility, obtained from the iron 

 mine of Jaberg, not far from Jonkoping, in Sweden. 

 He named it Vanadium, from Vanadis, a Scandina- 

 vian deity. The finery cinder of the cast iron of 

 Jaberg contains more vanadium than the iron itself, 

 and it exists in it in the condition of vanadic acid. 

 To obtain the metal, the following process is 

 adopted : The finery cinder is powdered, and mixed 

 with nitre, and carbonate of soda, in the propor- 

 tions of one part of cinder, one of nitre, and two 

 parts of carbonate : this mixture is strongly calcined 

 for an hour. The soluble portion of the powdered 

 mass is dissolved by boiling water : the solution is 

 filtered, and the excess of alkali saturated with 

 nitric acid, and afterwards precipitated with muri- 

 ate of barytes, or acetate of lead. The precipitate 

 is vanadate of barytes or lead, containing also some 



