tiles and fishes. The portion of a tooth above the socket is called the crown, the concealed part the root or fang, between these being a more or less well marked constriction or neck. Vertebrate teeth, like bones, have for their earthy basis phosphate of lime, the enamel also containing fluate of lime; the teeth of invertebrates consist essentially of carbonate of lime. The body of a tooth is composed of a tissue called dentine, the outer crust of the cement or crusta petrosa, with generally a thin covering of enamel on the grinding surface. Dentine is disposed in the form of very minute cells and tubes of an animal gelatinous basis, containing the earthy matter, some of its varieties closely resembling bone; the cement corresponds in texture with the osseous tissue of the animal, forming nearly of the mass of the elephant's molars, and wearing away sooner than the dentine; the enamel is the hardest constituent of the tooth, and the hardest of the animal tissues, consisting of the earthy matter contained in the canals of an animal matrix.-There are 3 kinds of teeth distinguishable in mammals, viz., incisors, canines, and molars. The incisors are situated in the front and median portion of the jaws, and have a simple flattened root and a thin cutting edge, suitable for dividing and collecting food, as in the jaws of the beaver and squirrel and in the lower jaw of the ox. The canines, 4 in number, are next to the incisors, separated from them by an interval, except in man; the crown is conical, and the root long and simple; they are the so called eye and stomach teeth in man, and form a striking character and very formidable weapons in the carnivora; they are best adapted for securing and tearing a living prey. The molar teeth are the most posterior, and have flattened and tuberculous crowns suited for grinding down vegetable food; they are most developed in herbivorous animals; the roots in man are often much bifurcated, rendering extraction difficult.-Teeth are so intimately related to the food and habits of animals, so easily examined from their situation, and of such indestructible materials, that they are of the first importance in the classification of animals, both living and fossil. The importance of the teeth in preparing food for the digestive process has been noticed under DIGESTION; in man they are also subservient to beauty and to speech; when fully formed they are subject to decay, but have no inherent power of reparation; they may increase by abnormal growth of the cement, their most highly organized constituent. For the diseases and the mode of treatment of the teeth, see DENTISTRY.-In fishes the teeth vary from none in the sturgeon and lophobranchs to countless numbers in the pike and the siluroids; they are usually conical, but sometimes flattened or pavement-like, villiform, serrated, and cutting; they may be situated on any of the bones of the oral cavity, on the tongue, and in the pharynx; in most cases they are firmly united to the jaws by continu

ous ossification, but in some are movable; they are composed of dentine and its modifications, enamel occurring in only a few cases, like the parrot fish (scarus); and they are frequently shed and renewed, the germs being developed from the free surface of the buccal membrane. Among reptiles, the whole order of chelonians (tortoises and turtles), and also the toad family among batrachians, are without teeth; in the others these organs are usually simple, and adapted for seizing and holding but not chewing their food; the number is never so small nor so large as in fishes, and is rarely characteristic of species; they are generally_conical, sharp, and smooth, and may be placed on any of the bones entering into the structure of the mouth; the base never branches into diverging fangs, and in most is anchylosed in various ways to the bone which bears them, as noticed under the different families; dentine and cement are always present, and sometimes enamel, as in the saurian crown. Among mammals, some of the edentates, as ant-eaters and pangolins, have no teeth; in the others they are implanted in sockets, and the molars have 2 or more roots when they have a limited growth; they are confined to the superior, inferior, and intermaxillary bones, a single row in each. Mammals have been divided by Owen into monophyodonts, or those which generate a single set of teeth, and diphyodonts, or those which generate 2 sets of teeth; the former include the monotremes, edentates, and carnivorous cetaceans, and the latter all the other orders. The teeth of mammals and their dental formulas have been sufficiently described in their respective divisions.-For full details on this subject the reader is referred to the following writings of Prof. Richard Owen: Odontography" (London, 1840-'45); article "Teeth” in vol. iv. of the "Cyclopædia of Anatomy and Physiology" (1852); and "The Principal Forms of the Skeleton and Teeth," in vol. i. of Orr's "Circle of Sciences" (London; reprinted in Philadelphia, 1854).

TEETH, MINERAL. See DENTISTRY, vol. vi. p. 396.

TEFFT, BENJAMIN FRANKLIN, D.D., LL.D., an American clergyman, born in Oneida co., N. Y., in 1813. He commenced a course of classics and mathematics at an early age, and at 15 entered upon the study of law, but subsequently, after receiving a collegiate education with a view to the ministry, applied himself for 4 years to legal, metaphysical, and historical studies. He then became pastor of a Methodist Episcopal church at Bangor, Me., and two years later president of a classical seminary at Providence, R. I., where he remained one year; and after residing for a year in Boston, he was called to the professorship of Greek and Hebrew in the Indiana Asbury university, where he remained 3 years. He has since been general editor of the books and magazine of the Methodist book concern at Cincinnati, and still later president of Gene

see college. He has published "The Shoulder Knot, or Sketches of the Threefold Life of Man" (New York, 1850); "Hungary and Kossuth, or an American Exposition of the late Hungarian Revolution" (Boston, 1852); and "Methodism Successful, and the Internal Causes of its Success" (New York, 1859).

TEFLIS. See TIFLIS.

TEGEA, an ancient and powerful city of Greece, situated in the S. E. part of Arcadia. Its territory was called Tegeatis. It is mentioned in the Iliad. Its early history was marked by a constant war between it and the Spartans, who for a long time unsuccessfully attempted to bring about its subjection. Charilaus, a Spartan king, invaded at one time the land of the Tegeans, but was defeated and made prisoner. Two centuries later Leon and Agesicles were unsuccessful in another invasion; but about 560 B. C. the city fell into the hands of the Spartans, and though retaining its independence was bound to furnish a military force when required. In the Persian war 500 Tegeans fought at Thermopylæ, and at Platea 3,000. Subsequently they were again at war with Sparta, and were defeated; but during the entire Peloponnesian war they adhered constantly to the side of the Spartans, as they did also in the Corinthian war which followed. After the battle of Leuctra in 371, the Spartan party having been expelled, Tegea became a member of the Arcadian confederacy, and its citizens in 362 fought under Epaminondas at Mantinea. Subsequently it joined the Ætolian league, and in the wars between Sparta and the Achæan league was alternately in the hands of the contending parties. After the Roman conquest of Greece, it continued to be a place of considerable importance, but toward the close of the 4th century of the Christian era was taken and totally destroyed by Alaric.

TEGNER, ESAIAS, a Swedish poet, born at Kirkerud, Wermland, Nov. 13, 1782, died in Wexiö, Nov. 2, 1846. He was graduated at the university of Lund in 1803, and made professor of Greek literature there in 1812, having in the interval been an under professor. A patriotic poem entitled Svea (Sweden) was his first production, and obtained for the author the prize of the Swedish academy. In 1824 he was made bishop of Wexiö, and from that period devoted himself to his episcopal duties. The most admirable of Tegnér's poems is Frithiofs Saga ("The Legend of Frithiof"), which first appeared in 1825. It consists of 24 cantos, of different metres, each according to the style of the subject, and in imitation of the old Icelandic sagas. The most striking passages have been admirably set to music by Crusell, a Swede, and are constantly sung in family circles throughout the country. Among the works of Tegnér may be cited also the "First Communion;" "Axel," the story of a lifeguardsman of Charles XII.; the "Song of the Sun," a fine bacchanalian; the "Hero," a sketch of Napoleon; the "Sage," a didactic poem; and

Nattwardsbarnen ("The Children of the Lord's Supper"). His writings were collected and edited by his son-in-law Prof. Bottiger (6 vols., Stockholm, 1848). The best translations of Tegnér's poems, according to his own opinion, are those of Longfellow.

TEHAMA, a N. co. of California, drained by the Sacramento river; area, about 1,000 sq. m.; pop. in 1860, 4,044. The surface is hilly, and the soil fertile and well adapted to grazing. The productions in 1858 were 133,450 bushels of wheat, 232,000 of barley, and 18,886 lbs. of wool. A large amount of timber is exported. There are two Indian reservations in the county, on which 8,000 Indians are settled. Capital, Red Bluffs.

TEHERAN, or TEHRAN, the capital of the kingdom of Persia, and of the province of IrakAjemi, 70 m. S. from the Caspian sea and 210 m. N. from Ispahan, in lat. 35° 41′ N., long. 51° 23′ E.; pop. in winter about 80,000. The town stands in a sandy plain, with mountains to the N. and E., and a fertile, well cultivated country to the W. It is of a square form, surrounded by thick walls about 4 m. in extent, and is entered by 4 gates ornamented with the figures of different kinds of animals. Inside there are many vacant spaces and gardens and extensive ruins; but the streets are narrow, irregular, unpaved, and exceedingly filthy. The houses are badly built and mean in appearance. The royal palace consists of a great number of buildings and gardens, and covers nearly of the area enclosed within the walls. It is fortified, and has a seraglio surrounded by lofty walls and guarded with great care. The bazaars are extensive, but are wretchedly kept and very dirty. There is a royal foundery, where guns of large caliber are made. One of the mosques is roofed with plates of gold. In summer the climate is unhealthy, and the monarch and about of the inhabitants leave the city and encamp on the plains of Sultanieh. On a hill in the neighborhood the king has a palace and beautiful gardens.-Under the Suffavean dynasty Teheran was not a place of importance. It was almost destroyed by the Afghans after the battle of Salman-abad; but it was afterward rebuilt, and has since received frequent additions to its fortifications. It was made the capital of Persia in the early part of the 18th century.

10

TEHUANTEPEC, a territory of Mexico, organized about 1850, and comprising the isthmus of the same name, bounded N. by the gulf of Campeachy, E. by the states of Tabasco and Chiapas, S. by the gulf of Tehuantepec, and W. by Vera Cruz and Oajaca; area, about 16,000 sq. m.; pop. in 1854, 82,395. Its width from gulf to gulf is 130 m. It is drained by the Coatzacoalcos river, which flows northward, discharging into the gulf of Campeachy, and extending about & of the width of the territory; and by the Tehuantepec river, flowing into the gulf of the same name. several lakes and lagoons in the territory.

There are

Capital, Minatitlan.-At one time it was proposed to construct a ship canal across the isthmus, improving the navigation of the Coatzacoalcos for a part of the distance, and using some small lakes as reservoirs at the height of land for the canal; but a subsequent project was the connection of the gulf and ocean by a railway which should form a part of the route from New Orleans to San Francisco, the isthmus being S. S. W. of New Orleans, and the route shorter by several hundred miles than any other proposed ocean route. Measures were taken to secure the grant of the route from the Mexican government, and it was provisionally opened by the despatch of vessels to the ports on either side, and the transportation of passengers by stage across the isthmus. The want of any good harbor on either side of the isthmus, and the immense expense which would be incurred in the erection of breakwaters adapted to produce even a partial shelter, as well as the shallowness of the harbors, have caused the project to be relinquished.-TEHUANTEPEC, a town of the above territory, is situated on Tehuantepec river, about 10 m. above its mouth, and 150 m. E. S. E. from Oajaca; pop. 14,000. It has salt works and cotton factories, and a considerable pearl fishery in which many of the inhabitants are engaged. Indigo is raised in the vicinity, and a purple dye is procured from a shell fish abundant there. The harbor is shallow and exposed to the hurricanes from the N. W.

TEIGNMOUTH, JOHN SHORE, baron, an English statesman, born in Devonshire, Oct. 8, 1751, died Feb. 14, 1834. He entered the civil service of the East India company as a cadet in 1769, and by successive promotions reached in 1786 the position of member of the supreme council under the governor-general, Lord Cornwallis, whom in 1793 he succeeded in office, and in 1794 he was made a baronet. The new settlement of landed property in the presidency of Bengal, and the new judicial system introduced under Lord Cornwallis, were mainly attributable to the efforts of Sir John Shore. He retired from office in the latter part of 1797, and was created Baron Teignmouth in the peerage of Ireland. Subsequently he was for many years a member of the board of control, and from 1804 until his death president of the British and foreign Bible society. He published in 1804 a memoir of Sir William Jones, whom he succeeded as president of the Asiatic society, and in 1807 he edited his works in 13 vols. 8vo. His "Life and Correspondence" was published by his son (2 vols., London, 1837).

TELEDU, or TELAGON, the name of the mydaus meliceps (F. Cuv.), a carnivorous animal of the family mustelina, emitting a fetid odor like that of the skunk, inhabiting Java, and confined exclusively to mountains 7,000 feet at least above the level of the sea. It is about the size of a polecat, being 15 inches long with a tail of half an inch, but the body is much thick er, the neck and limbs short and stout, and the

feet plantigrade; the teeth are as in the skunk, the snout prolonged like that of a pig, the head badger-like, ears very small and concealed by the long hair, and the eyes very high in the head; the claws of the fore feet are long, compressed, nearly straight, and adapted for digging; the fetid secretion is poured out from 2 glands near the end of the rectum, opening about half an inch within the canal. It is a nocturnal animal, making a shallow burrow, and feeding on insects, larvæ, and worms. The color is blackish brown, with a narrow whitish stripe extending from the occiput to the tail. It is slow in its movements, trusting for safety to its fetid odor; the natives are fond of its flesh, which is almost always fat and tender; it sometimes does considerable mischief by destroying the roots of young plants in cultivated districts. TELEGRAPH (Gr. Tηλe, afar, and ypapw, to write), an apparatus by which intelligence is communicated to a distance. It properly includes the various methods of signalling, of which some account has been given in the article SIGNALS. The most obvious form of these, and one which has been adopted by different nations from remote antiquity, is that of fires made upon commanding points, which were visible at great distances, by their smoke by day and their light by night. By preconcerted arrangements, these are made to designate such intelligence as it may be desirable to communicate, such as the warning of the approach of an enemy, and to call the people together for their protection. The Roman generals, as described by Julius Africanus, perfected this method of communicating intelligence, so as to spell words by means of fires of different substances. The North American aborigines made use of regular stations over the western country for these signals; and the Indians of the north-west territory in this way communicated intelligence of the approach of Fremont, as he passed through their regions. Polybius describes two methods of telegraphing by means of torches; and Bishop Wilkins, after giving an account of this in his book entitled "Mercury, or the Secret and Swift Messenger," describes a method of conversing at a distance with 3 lights or torches at night, which may be so used as to indicate the 24 necessary letters of the alphabet, these being divided into 3 classes of 8 letters each, which are severally designated by one, two, or three torches, and the number of the letter by the number of times the torches are elevated or displayed. Another method was also proposed by Bishop Wilkins, in which intelligible signals were conveyed by means of two lights attached to long poles; and for long distances he suggested the use of the then newly invented telescope, or, as he called it, "Gallileus his perspective." A variety of systems of telegraphic signals were brought into notice by different inventors in the 17th and 18th centuries, one of the earliest of which was that of Dr. Robert Hooke described in the "Philosophical Trans

logical order. The discovery by Dr. Watson in 1747, that the earth itself and intervening bodies of water might be made use of to complete the electric circuit, was one important step toward this application. He transmitted shocks across the Thames and the New river, in one instance at Shooter's Hill the circuit being composed of 10,500 feet or about 2 m. of wire, and 2 m. of the earth; and he supported his wires, as now practised on the telegraph lines, upon posts. Signals were communicated by means of the electric shock from one apartment to another by Lesage at Geneva in 1774, and by Lomond in France in 1787, probably by causing the divergence of pith balls on some concerted plan; and in 1794 Reizen of Germany employed the electric spark for telegraphing, making use of an ingenious arrangement of lines and interrupted spaces upon strips of tin foil, so arranged that when these spaces were illuminated by the spark the form of the letter or figure was exhibited. He employed 37 wires from one station to another, each one of them communicating with one of the letters or figures, and each one connecting with a return wire, thus making 72 in all. This plan is described in vol. ix. of "Voigt's Magazine." Cavallo in his "Treatise on Electricity" (1795) suggests the explosion of gunpowder to call attention, and then the transmitting of signals by succession of sparks at intervals and in numbers according to the system agreed upon. Don Francisco Salva of Madrid and Sr. Betancourt constructed similar telegraphs at Madrid in 1797 and 1798, one of them extending between Madrid and Aranjuez, a distance of about 26 m. This, too, is noticed in vol. xi. of the work just referred to. Salva communicated his plans to the royal academy of sciences at Barcelona, and according to the journals of 1797 they were highly approved by the minister of state. Salva appears to have had a clear idea of the practicability of this electric communication even beneath the sea, and in the last of his memoirs he proposed to substitute the voltaic pile for the electrical machine. Other attempts to employ machine or friction electricity were made by Francis Ronalds at Hammersmith, England, in 1816, on a line of 8 m.; and in 1827 by Harrison G. Dyar at the race course on Long island, N. Y., on a line of 2 m. in length. The latter made use of iron wire, glass insulators, and wooden posts for supporting the wire, and employed the chemical action of the electric current to change the color of litmus paper as his method of communicating. Ronalds introduced the plan of employing a clock at each of the two stations, both of them running together exactly, and each bringing into view one after the other the letters of the alphabet arranged upon a disk which revolved behind a screen with an opening for one letter. Each clock was provided with two pith balls connected with the electrical machine at the other station; and as the shock was passed the divergence of these called the

attention of the other operator to the letter then in view. As the letters appeared in succession they spelled out the message communicated. The clock movement is an important feature in most of the modern telegraph systems. The voltaic pile, discovered in 1800, furnished in its constant current a more promising agent for transmitting intelligence than the sudden and transient shock of the electrical machine; and electricians were not long in testing its capacity for this purpose. Sömmering commenced his experiments in 1809, and devised a plan of telegraphing which was as perfect as was practicable in the condition of the science at that time. He made use of 35 wires, each terminating in a gold point, and all the points were set up vertically on a horizontal line at the bottom of a glass reservoir of water. In the other direction these wires, brought together in a tube, extended to the other station, where they again diverged, each one terminating in a brass plate, and the plates attached along a horizontal wooden bar. The plates at one end and the points at the other were marked with corresponding letters, and the current from the battery was established whenever two of the brass plates were touched, one with the negative and one with the positive pole. Decomposition of the water immediately occurred in the reservoir on the two corresponding gold points, the one producing hydrogen and the other oxygen gas, and the letters thus designated were noted down as part of the message communicated. Sömmering found that the addition of 2,000 feet of wire produced little or no sensible additional resistance, and that the galvanic action was instantaneously developed at least for the distance of about 3,000 feet. The galvanic batteries then known were however inapplicable to the transmission of currents through great distances, both on account of not continuing long in action, and also for want of sufficient intensity without using an inconvenient number of pairs; and no further progress was made in perfecting the electric telegraph until the principles of electro-magnetism had been developed. (See ELECTRO-MAGNETISM.) The first discovery in this branch of science was that by Oersted of Copenhagen, in 1819, of the electric current as it passes through a wire causing a magnetic needle near by to place itself at right angles to the current, and that the direction of the movement may be changed by changing the connection of the wires with the two poles of the battery. Schweigger of Halle in 1820 discovered the method of increasing the deflection by placing the wire that carries the current around the needle, and this improvement is adopted in all the telegraphs of this character. The same year Ampère laid before the academy of sciences at Paris the plan of a telegraph based on the movement of magnetic needles thus induced. Each needle was to stand for a separate letter or figure, and consequently a great number was required. The early telegraphs of