Page:The American Cyclopædia (1879) Volume III.djvu/543

 CADIZ CADMIUM 537 are narrow, but regularly laid out; the finest is the calle Ancha, which contains the bolsa, or exchange, and is connected with the prin- cipal square, the plaza San Antonio. The city is divided into four quarters, containing 6 great and 23 smaller squares, and 260 streets. It has 2 cathedrals, 7 churches, 13 convents, 2 theatres, and a bull ring. There are some fine paintings in the city. Mu- rillo fell from the scaffold while painting a picture which is in the convent of San Fran- cisco, and died from the effects of the fall. The casa de misericordia is a large hospital, and there are other charitable institutions. There are also a custom house, colleges, a draw- ing academy, and an observatory. The cli- mate of the city is hot, and it is at tunes ren- dered uncomfortable by the winds from Africa. The manufactures are not of much importance, hut fans, mantillas, gloves, guitars, and sweet- meats are made. Its chief importance is com- mercial. The harbor is excellent, although changes produced by the action of the river Guadalete and other causes tend to obstruct its entrance. Upon the discovery of America Cadiz attained great commercial importance. It was the port from which the trade with the Spanish colonies was carried on ; but when these colonies became independent Cadiz lost much of its commerce. Its position, however, at the entrance of the Mediterranean and at the southern end of the peninsula renders it still commercially the most important port of Spain. Its business has been increased by the opening of the railway from Seville, and by improvements which have been made in the harbor. Merchandise destined for Seville is commonly unloaded here. The principal ar- ticles of import are sugar, coffee, cocoa, spices, indigo, rice, wheat, salt fish, butter, cheese, hides, cotton, wool, linen, iron, brass, glass, and earthenware. Among the exports are fruits, brandy, barilla, cork, lead, quicksilver, raw silk, paper, silk and woollen manufactures, and lace. Wine is, however, the main article of export; the value shipped from Cadiz and the other ports around the bay in 1864 was $6,300,000. Cadiz is the starting point for Spanish mail steamers for the colonies in America, Africa, and the East ; there are also lines of steamers to England, Gibraltar, Lisbon, Marseilles, Havre, Amsterdam, and Hamburg. Cadiz was founded about 1100 B. C. by the Phoenicians, who called it Gadir. Before the second Punic war it belonged to the Cartha- ginians, but in 206 B. 0. surrendered to the Romans, who changed the name to Gades. The remains of a temple of the Phoanician Her- cules, and some other edifices of the ancient city, are still visible at low water. It fell into the hands of the Goths, from whom it was taken in 711 by the Arabs, who held it till 1262, when it was taken by the Spaniards. It was long known by the name of Cales to the Eng- lish, by whom it was taken and sacked in 1596 ; the booty was immense ; 13 ships of war and 40 huge treasure galleons were de- stroyed, causing almost universal bankruptcy in Spain. It was unsuccessfully attacked by the English in 1625, was blockaded by Admiral Blake in 1657, and was again unsuccessfully attacked by the English in 1702. From 1810 to 1812, when it was the seat of the central national junta, it was invested by the French, who raised the siege upon the approach of Wellington. In 1823 it surrendered to the duke of Angouleme, after a siege, which was the closing operation of the French interven- tion in favor of Ferdinand VII. It has since been conspicuous for its liberalism in several crises of Spanish affairs. The first movement in the revolution which overthrew the throne of Queen Isabella took place at Cadiz, Sept. 17, 1868. CADMIA (Gr. KaSfieia), a name applied by the Greeks to zinc ore, in honor of Cadmus, who first introduced the manufacture of brass into Greece. The same term is also applied to the impure oxide of zinc found in chimney stacks in the metallurgical working of ores contain- ing traces of zinc. The zinc ore is now called calamine. CADMIUM. In 1818 the attention of chem- ists was called to some samples of zinc that were sold for medicinal purposes ; they gave, when in solution, a suspiciously yellow color with sulphuretted hydrogen, and hence were condemned as containing arsenic. A number of chemists were furnished with specimens for examination, and several of them detected evidences of a new metal at the same time. Friedrich Stromeyer, professor of chemistry at Gottingen, was the first to publish, in Septem- ber, 1818, a full account of his investigations into the properties of the substance. He gave to the new metal the name of cadmium. Kar- sten simultaneously proposed to call it meli- nium, from the quince-yellow color of one of its compounds ; Gilbert gave it the name of Juno- nium, from the planet Juno ; and John christ- ened it Iflaprothium, after the chemist Klap- roth ; but cadmium is the only name now rec- ognized. The discovecy of cadmium forms an era in the line of scientific research. It was the first metal found in a compound and not in an ore, and it could not have been detected until chemical analysis had reached an advanced state of accuracy. Traces of it were soon found in zinc ores, but it was not till 20 years from the time of Stromeyer's publication that an ore of cadmium was discovered. Lord Greenock at that time described a mineral which had been picked up on his estate, and which proved to be a cadmium blende, analogous to zinc blende or to galena. The new ore was called Green- ockite, and since that time it has been found in various localities ; it is, however, a very rare mineral. For commercial purposes, the metal is obtained from zinc ores and furnace deposits. By subjecting zinc to downward distillation, the first portions that come over often contain cadmium. The pure metal is oh-