apparatus. Something similar to this has been projected in Australia, where the peculiarities of the climate permit the immediate threshing of the grain as soon as cut. It is somewhat doubtful whether so complex an apparatus will meet with perfect success in practice. But it is not impossible that an apparatus itself drawn by horses, but with the sickle and threshing-cylinder driven by a steam-engine closely boxed on the wheeled frame, might harvest and thresh the grain much more cheaply than by present methods. The plan would not be more audacious than that experimentally carried into effect a half-century since in Devonshire, England, of connecting a threshing and winnowing apparatus with a run of mill-stones, so that the grain was stripped from the straw, separated from the chaff, ground, and bolted at one continuous operation.

JAMES A. WHITNEY.

Thrift, the Armeria vulgaris, a European seaside and mountain plant, found also on British American shores, and often grown in gardens as an edging for flower-borders. It has diuretic powers. A. latifolia is a fine ornamental plant from Portugal. They are of the order Plumbaginaceæ.

Thrips [Gr. Opi], a genus of insects which gives name to the family Thripidae, an interesting group of degraded organisms, generally considered to be hemipterous, although their position is not quite established. The Thripida are destructive to grain, flowers, and the bark of growing plants. Thrips cerealium is one of the most destructive species. It is a very minute insect, with long fringed wings, but it appears to leap rather than to fly.

Throat, Diseases of. Although the specialty of the study and treatment of throat diseases is designated "laryngology," it includes diseases of the posterior nares, the fauces, pharynx, and larynx. Exceptionally, some of these diseases may be suspected or even diagnosticated from symptoms only, as laryngitis from hoarseness, stridulus, and aphonia; chronic tonsillitis from muffled voice and habitual snoring; elongated uvula and papular pharynx from habitual spasmodic pharyngeal cough. But physical exploration, the direct examination of the oral cavity and the passages to the posterior nares and larynx, is essential

ि

FIG. 1.

both to diagnosis and to correct treatment. Simple examination-the depression of the tongue by a spoon or tongue spatula-will suffice in many cases, exhibiting the tonsils, soft palate, uvula, posterior wall of the pharynx, and the top of the epiglottis. To discover the root of the tongue, the entire epiglottis, the true and false vocal cords, the chink of the glottis, and even the upper rings of the trachea and division of the bronchia, the laryngoscopic mirror must be employed. Laryngoscopy may be performed by the use of either bright sunlight or a concentration of artificial light. Specialists employ lamps with condensing prisms, and where very bright light is desired the oxyhydrogen light is used; with such methods of illumination the examination la conducted in a dark room. A good light, whether the sun's rays or artificial, is reflected, by a concave mirror held by the physician or worn

FIG. 2.

Healthy Larynx. upon a head-band, into the patient's opened mouth. The patient's tongue being drawn forward and gently held, a small circular or oval laryngeal mirror is introduced. There are several sizes of mirrors, varying in diameter from onequarter to one inch in diameter; they are attached to delicate handles at an angle, so that when passed to the back

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of the throat they catch the rays thrown into the mouth by the concave mirror, and reflect them downward, illuminating the larynx. The parts thus rendered luminous present a distinct picture in the small laryngeal mirror above them; and this is seen by the observer through the perforated centre of the concave mirror, since the axes of light return by reflection to the reflecting surface from which they started.

The laryngoscopic examination is easily accomplished after a brief period of practice. More difficult is the exploration of the upper pharynx and the posterior nares, termed rhinoscopy. The uvula has to be drawn forward, and the reflecting laryngeal mirror passed well back and turned upward. When correctly held, a distinct image of the septum between the nostrils, and of the extensive corrugated surfaces of the naso-pharyngeal spaces, is transmitted to the eye (Fig. 3). Patients are easily trained to permit the presence of the throat mirror, and even to explore their own throats (auto-laryngoscopy). The move

ments of the vocal cords are displayed best by phonating a (eh). All of these several connecting parts of the throat are richly supplied with blood-vessels, lined by a mucous membrane, secreting mucus. They are therefore liable to hypersecretion of mucus, or catarrh, which may be

acute, subacute, or chronic; to active and passive congestions, inducing redness, heat, and swelling; to active inflammations, with formation of submucous abscess, erosion of the epithelial covering of the mucous membrane, or ulceration and sloughing of its deeper layers. Such destruction of soft tissue may induce necrosis of the underlying hard structures, the nasal and laryngeal cartilages. Inflammation may terminate in an exudation, developing organized membranes, as those of croup and diphtheria. Repeated congestions and inflammations tend to engorge and hypertrophy the structures of the mucous membrane and glandular bodies embedded in it. The papillæ of the back of the throat and of the columns of the fauces are very often thus enlarged. The surface is seen to be studded with prominent ovoid papules or tubercles, a condition known as "clergyman's sore throat," and technically as "papular pharyngitis." Polypoid growths of variable size develop in the nares, pharynx, and on and around the vocal cords-products of papular growth and of granulation process.

A most alarming and critical condition is acute cedema of the glottis. The secretion of the region of the larynx being suddenly checked, as by cold, or the seat of sudden determination of blood, serum transudes from the overloaded blood-vessels into the loose submucous connective tissue, and creates a sudden dropsy and tumefaction. The distended, swollen structures overlap the opening of the glottis and occupy the ventricles of the larynx, preventing inspiration, and threaten immediate death by suffocation. The laryngoscopic mirror definitely locates the seat of these dropsical sacs, and is the sure guide to efficient scarification and evacuation of their contained fluid. The vocal cords may be affected by spasms, producing hoarseness, aphonia, and labored respiration, in which case the mirror detects the unusual approximation and irregular action of the cords, and excludes the presence of more serious inorganic disease. One of the vocal cords may be found paralyzed, inactive, and relaxed, while the other remains normal. Such paralysis of a cord may be due to vocal inflammation or abnormal growth, or may depend upon lesions of the recurrent nerves in the neck, or again, coexisting with paralysis of one-half of the body, depend on a lesion of the brain-softening, embolism, apoplexy. Ulceration or inflammation may so seriously damage the vocal cords that cicatricial or scar-like tissues are formed, tending to contract and harden; in time the chink of the glottis becomes contracted and narrow-termed "stenosis of the larynx." The aperture being no longer adequate for the ingress or egress of air, gradual suffocation must ensue unless surgical relief is afforded. Extensive destruction of the vocal cords often occurs from syphilis and epithelial cancer.

The more accurate diagnosis of throat diseases, and intelligent study and classification by aid of laryngoscopy, have led to corresponding progress in treatment. Applications are no longer applied at random by probangs, uncertain of the condition that exists and of the parts which are reached. Remedies are applied with accuracy by various methods, with definite regard for the indications of each case. Astringents-as cold water, alum, tannin, tincture

of iron, and solutions of nitrate of silver-are employed to contract blood-vessels, lessen congestions and relaxations of surfaces. Caustics are used to remove papular and granular developments, and induce absorption of hypertrophied structure. Local applications are made to heal ulcers. Inflammation is checked, limited, and cured by warm solutions and vapors impregnated with salts of soda, ammonia, and potash, or in other cases by cold gargles or spray. The salines tend to increase and liquefy the secretions of the throat; resin oil and astringent agents lessen them; carbolic acid, chlorine, etc., disinfect them when septic. Anodynes are given to allay pain, either by the stomach or locally. Electricity is applicable directly to the paralyzed vocal cord. The knife is constantly of service in treating throat diseases, for the excision of the tonsils and uvula, opening abscesses, the incision of hard papules, preceding use of caustics, removal of polypi, the scarification of cedema of the glottis, and for the operations of tracheotomy and laryngo-tracheotomy, whenever, by congestion, inflammation, ulceration, stenosis, tumors, cancer, sudden ædema, croupous or diphtheritic membrane, or whatsoever obstruction, the larynx is closed to the passage of air and death is imminent by suffocation.

E. DARWIN HUDSON, JR. REVISED BY WILLARD PARKER. Throckmorton, cap. of Throckmorton co., Tex. (see map of Texas, ref. 2-G, for location of county). P. in 1880, 37.

Throcmorton (Sir NICHOLAS), b. in England about 1513; became a page to the duke of Richmond; was afterward a member of the households of Henry VIII. and of the queen-dowager; was engaged in the French campaign 1544-47; was appointed under-treasurer of the mint by Edward VI., to whom he was, as an earnest Protestant, much attached; was present at the death of Edward 1553; was concerned in Wyatt's rebellion 1554, for which he was imprisoned in the Tower and tried for treason, but acquitted; resided on the Continent during the reign of Mary; appointed by Elizabeth chief butler of England, and subsequently chamberlain of the exchequer; ambassador to France 1559-63; afterward sent on a mission to Mary Queen of Scots, and entered into the scheme for her marriage to the duke of Norfolk, for which he was disgraced and committed to the Tower 1569. D. Feb. 12, 1571.

Throm'bus [Gr. @póμßos, a "clot"], in pathology, designates the fixed venous blood-clot. Thrombus often accompanies phlebitis. It is conceded that dilatation or contraction of a vessel, or great weakness of the heart's action, may favor the formation of thrombus, but whether a special miasmatic influence may have the same result is not settled. Slight pressure also on the side of a vein will sometimes induce this coagulation. Clots thus formed in a vessel increase and extend, and, moreover, they are liable to putrefactive changes, whence follow metastatic abscesses and a long train of deplorable consequences. When thrombus exists, a rich diet, tonics, and pure air afford the only prospect of recovery.

Throop (ENOS THOMPSON), b. at Johnstown, Montgomery co., N. Y., Aug. 21, 1784; studied law; was admitted to the bar in 1806, and removed to Auburn, N. Y.; was appointed clerk of Cayuga co. by Gov. Tompkins; elected to Congress in 1814; appointed circuit judge of the 7th district of New York by Gov. Yates; in 1828 was elected lieutenant-governor of New York, with Martin Van Buren as governor, and became acting governor on the latter's retirement from the governorship to accept a place in Pres. Jackson's cabinet; renominated and re-elected in 1830 at the head of the ticket; declining a third term, removed to Michigan, where he conducted extensive improvements in that sparsely-settled Territory. Returning to New York, he ended his days amid the scenes of his early life, his death occurring Nov. 1, 1875, at Willow Brook, on the shore of Owasco Lake, his former home.

Thrupp (FRANCIS JOSEPH), b. in England in 1827; educated at Winchester School and at Trinity College, Cambridge, where he obtained a fellowship: took orders in the Church of England; travelled in the East; became vicar of Barrington, Cambridgeshire; d. there Sept. 24, 1867. Author of Ancient Jerusalem, a New Investigation into the History, Topography, and Plan of the City, Environs, and Temple (1855), An Introduction to the Study and Use of the Psalms (2 vols., 1860), The Song of Songs, a New Translation (1862), and other works; contributed to Dr. William Smith's Dictionary of the Bible, and prepared part of the commentary on the Pentateuch in the Speaker's Commentary.

Thrush, the English name applied to various species of the family Turdida, and especially to those of the genus Turdus. As understood by American authors, this genus embraces the species of which the bill is conical, subulate, and shorter than the head, the tip of the upper mandible

slightly decurved, the rictus provided with moderate bris tles, the wings rather long and pointed, and with the first primary small, the tail nearly even, and the tarsi with continuous plates. The genus thus understood has, however, been subdivided into five sub-genera (considered by some as genera), which exhibit differences in the relations of the sexes, the size and shape of the bill, etc. It includes some of the finest songsters and most familiar birds of the northern hemisphere. Most of the American species belong to the section Hylocichla, and among these is the wood thrush, or T. mustelinus, famous for its song. To the section Planesticus belongs our familiar robin (T. migratorius). Baird, Brewer, and Ridgway admit 8 species as inhabitants or visitants of North America and the U. S. THEO. GILL.

Thrush, an abscess in the sensitive frog of the horse's foot. Cleanliness and the paring away of loose pieces of the frog are useful toward a cure. Carbolic-acid lotions or occasional sprinkling with calomel will materially hasten the recovery. This disease is generally the result of neglect. Thucydides, generally considered the greatest historian the Greek people ever produced, was b. at Athens 471 B. C. He descended from a princely family in Thrace, and was connected with the families of Miltiades, Cimon, and Pisistratus. He was also rich; he owned those goldmines on the coast of Thrace, opposite the island of Thasos, which later were worked with so great profit by Philip of Macedon. He received the instruction of the philosopher Anaxagoras and the rhetorician Antiphon. In the eighth year of the Peloponnesian war (424 B. c.) he commanded an Athenian fleet of seven ships destined to defend the Athenian settlements along the coast of Thrace, especially the city of Amphipolis. The Spartan general, Brasidas, attacked this city at a moment when Thucydides and the fleet happened to be absent, and offered it very alluring terms of capitulation. It accepted them, and capitulated before Thucydides could reach it, and as a punishment for this misfortune or neglect he was driven into exile, and lived for twenty years in foreign countries-in Thrace, Peloponnesus, and Sicily. In 403 he returned to Athens, but two years after he was assassinated, whether in Athens or in Thrace is uncertain. His great work on the Peloponnesian war is unfinished. It reaches only to the year 411 B. c.; and the eighth book, which differs considerably from the preceding books, is said to have been written by his daughter. Although he is only thirteen years younger than Herodotus, the difference between them is very striking. It always remains the honor of Herodotus to have invented the art of history, but from him to Thucydides this art has made great progress both in style and method. Herodotus tells everything interesting, and tells it simply because he finds it interesting, but this prolixity sometimes becomes diffuse and garrulous. Thucydides tells only that which has a direct bearing on his subject, and tells it solely on account of this relation. This iron consistency makes him sometimes obscure, but his style belongs, nevertheless,

to a much more advanced civilization; it has reduced the volume of the expression one-half. Herodotus arranges his materials so as to make them all enter into a general view. With Thucydides there is very little arrangement. He takes the phenomena as they show themselves, and his labor consists in finding out the motive of the acting person and the cause of the visible effect; but this method belongs to a higher stand-point of historical art, as it is a deeper world it describes. His work has been edited by Poppo (Leipsic, 1821 seq., 11 vols.), Bekker (1832), Böhme (1856), Krüger (1846), and translated into English by Rev. S. T. Bloomfield (3 vols., 1829), Rev. Thomas Dale (1856), and Richard Crawley (1874). CLEMENS PETERSEN.

Thugs [from the Hindoo thugna, to "deceive"], a religious association, worshippers of the goddess Kali, who in bands of from 30 to 300 roamed all over India, and had established connections everywhere. They decoyed persons into their company, allured them to distant places, murdered and plundered them. But their motive was not so much lust of plunder as certain religious ideas, and of the spoil one-third was given to the goddess. Between 1829 and 1837 the British Indian government succeeded in breaking up these bands entirely. (See Ramasecana, or a Vocabulary of the Peculiar Language used by the Thugs (1836), by Capt. Sleeman, and The Confessions of a Thug, by Meadows Taylor (London, 1858).)

Thu'le, the name which Pytheas (at the time of Alexander the Great) gave to a land which he discovered after sailing six days in a northerly direction from the Orkney Islands. Later, the Romans used the name as a general signification for the northernmost parts of the habitable earth-ultima Thule. What island Pytheas meant by his Thule is unknown.

Thumb'screw, or Thumb'kin, an instrument of judicial torture formerly used in various parts of Europe,

but particularly in Scotland. The thumb was compressed by means of a screw. Its last official use was in the trial and on the person of Principal Carstairs in 1682, after the Rye-house Plot.

Thun (LEO), COUNT, b. at Tetschen, Bohemia, Apr. 7, 1811, studied jurisprudence in Prague; travelled in Germany, France, and England; held various positions in the administration, and became a member of the Bohemian diet in 1848. He took his seat among the extreme Left and gave his full support to the claims of the nationalists, in opposition to the government. In 1849 he was appointed minister of public instruction, which position he held till 1860; but he continued to be one of the leaders of the national party also after his retirement. Author of several political pamphlets.

Thun'berg (CARL PETER), b. at Jönköping, Sweden, Nov. 11, 1743; studied at Upsal under Linnæus; resided at the Cape of Good Hope 1771-73, and in Japan 1773-79; returned in 1779 to Sweden; succeeded Linnæus in 1784 as professor of botany at the University of Upsal; d. there Aug. 8, 1828. His principal works are-Flora Japonica (1784), Prodromus Plantarum Capensium (1794-1800), Icones Plantarum Juponicarum (1794-1805), Flora Capensis (1807-13), and Resa uti Europa, Africa och Asia (4 vols.,

1788-91).

Thunder. See LIGHTNING, by J. HENRY. Thun, Lake of, in the canton of Berne, Switzerland, at an elevation of 1775 feet above the level of the sea, is 10 miles long and 2 miles broad. On its eastern shore stands Interlaken, and on its north-western-or, properly speaking, on the Aar, about 1 mile from its exit from the lake-the town of Thun. Both these towns are every season visited by a great number of tourists journeying to the Bernese Oberland. Steamers ply on the lake.

Thurber (GEORGE), M. D., b. in Providence, R. I., in 1821; became professor of mathematics, medicine, and botany in the New York College of Pharmacy, and is co-editor of the American Agriculturist. He has edited American Weeds and Useful Plants, being a second and illustrated edition of Darlington's Agricultural Botany, and has contributed largely upon botanical subjects to the American Cyclopædia.

Thurgau, canton of Switzerland, bordering N. on the Rhine and the Lake of Constance, comprises an area of 384 sq. mn., with 99,552 inhabitants, of whom 69,231 are Protestants and the rest Roman Catholics. The surface is undulating, but not mountainous, except in the southernmost districts. The soil is very fertile, and agriculture is the main branch of industry pursued; several cotton and linen spinning and weaving factories are in operation. Cap. Frauenfeld.

Thu'rible [Lat. thuribulum, from thus, "incense"], or Cen'ser, in the Roman Catholic Church service, a vessel of silver suspended by four short chains. It is charged with burning charcoal, upon which incense is placed. The thurible is borne by an acolyte called the thurifer.

Thü'ringerwald ["the forest of Thuringia"], a mountain-range in Central Germany, extends along the right bank of the Werra, from the influx of the Horsel, for about 60 miles, and joins the Frankenwald in Northern Bavaria. Its highest point is Schneekopf, 3400 feet high. It is covered with pine forests, and consists mostly of granite, porphyry, and slate, interspersed with rich veins of iron ore. The country it occupies was formerly called Thuringia, but is now parcelled into many petty states.

Thurin'gia [Ger. Thüringen], the general name for that region of Central Germany which lies between the Hartz and the Thuringian Forest, the Saale and the Werra, and which comprises parts of the Prussian province of Saxony and the Saxon duchies. The name originated from the Thuringii, who settled here, but since the fifteenth century it has had no definite political signification.

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Rev. Thomas Thurlow, being rector of that parish; studied the classics at a school in Canterbury; entered Caius College, Cambridge, Oct., 1748; left the university without a degree on account of some breach of discipline 1751; became fellow-pupil, in a solicitor's office, with the poet Cowper; also studied law at the Inner Temple, where he was called to the bar Nov., 1754; became accidentally acquainted with one of the Scotch solicitors employed in the great Douglas case; was in consequence employed as junior counsel, gaining great distinction and the powerful patronage of the house of Douglas, one of whose members, the duchess of Queensberry, obtained for him the rank of king's counsel 1761; was elected to Parliament for Tamworth 1768; was a zealous supporter of Lord North; became solicitor-general Mar., 1770, attorney-general Jan., 1771, and lord chancellor and Baron Thurlow June 3, 1778, in reward for his powerful advocacy of the American war; retained the chancellorship by express command of the king through the succeeding administrations of Lords Rockingham and Shelburne, whose policy he vigorously and successfully opposed in the House of Lords; was excluded from the coalition ministry on its formation Apr. 9, 1783, but returned to office on the accession of the younger longer, in reliance upon the personal favor of the king, Pitt Dec. 23, 1783; retained the great seal eight years while frequently venturing to oppose the policy of the ministry; was dismissed from office on the demand of Pitt June 15, 1792, after which he became a bitter enemy of the government, but lived in comparative obscurity. He opposed the abolition of the slave-trade, and was a warm partisan of Warren Hastings. D. at Brighton Sept. 12, 1806. He was possessed of an overbearing dogmatism, which did duty for eloquence in Parliament, and had a great contemporary reputation for ability, which later generations have not confirmed. Neither his forensic nor judicial record exhibits any traces of a master-mind. He had no children, but by a new patent of peerage, executed 1792, his title was made heritable by his nephews, one of whom, EDWARD HOVELL-THURLOW, second baron (b. 1781; d. 1829), was a poet of some distinction. PORTER C. BLISS.

Thurman (ALLEN G.), b. at Lynchburg, Va., Nov. 13, 1813; removed to Ohio in 1819; received an academic education; studied law, and was admitted to the bar in 1835; was Representative from Ohio in the 29th Congress; elected judge of the supreme court of Ohio in 1851, and chiefjustice from 1854 to 1856; Democratic candidate for governor of Ohio in 1867; elected to the U. S. Senate, in place of Benjamin F. Wade, Mar. 4, 1869, and re-elected in 1874. His term of service expired Mar. 3, 1881; was prominent among the candidates for the Democratic nomination for President at St. Louis in 1876.

Thurs'day ["Thor's day;" Ger. Donnerstag], the fifth day of the week. The name seems to have originated among the later Roman pagans, who adopted the week of seven days, and named the fifth day Joris dies, "Jove's Day" (Fr. Jendi),

Thurston (ROBERT HENRY), son of Robert Lawton Thurston, b. in Providence, R. I., Oct. 25, 1839; was trained in the workshop of his father, and graduated at Brown University in 1859. He was engaged in the business firm of which his father was senior partner until 1861, when he entered the navy as an officer of engineers; served during the civil war on various vessels; was present at the battle of Port Royal and at the siege of Charleston; was attached to the North and South Atlantic squadrons until the close of 1865, when he was detailed as assistant professor of natural and experimental philosophy at the U. S. Naval Academy at Annapolis, where he also acted as lecturer in chemistry and physics. In 1870 he visited Europe for the purpose of studying the British iron-manufacturing districts, and in 1871 was appointed professor of mechanical engineering at the Stevens Institute of Technology. In this year he conducted, in behalf of a com

Thur loe (JOHN), b. in Essex, England, in 1616; studiel law was called to the bar at Lincoln's Inn 1647; enjoved the favor of Oliver St. John, through whom he obtained the post of secretary to the council of state 1652; was secretary of state 1653-60; sat in Parliament; was chief postmaster, privy councillor, governor of the Charterbouse, chancellor of Glasgow University, and suffered a short imprisonment at the Restoration. D. in London Feb. 21, 1668. His collection of State Papers was edited by Dr. Birch (7 vols., 1742).

Thurlow (EDWARD), BARON THURLOW, b. at Ashfield, near Stowmarket, Suffolk (according to others at Little Bracon-Ash, Norfolk), England, about 1732, his father,

on steam-boilers, in which for the first time all losses of heat were noted, and by condensing all the steam generated the quantity of water entrained by the steam was accurately noted. In 1873 he was appointed a member of the U. S. scientific commission to the Vienna Exhibition, served upon the international jury, edited the report of the commissioners, and published his own Report on Machinery and Manufactures, in 5 vols. (1875-76). In 1874 and subsequently he conducted at the Stevens Institute a series of researches on the efficiency of prime-movers and machines, and upon the strength and other essential properties of the materials of construction. In 1875 he was appointed a member of the U. S. commission on the causes of boiler explosions, and of the board to test the metals used in construction. He is a member of various scientific associations in the U. S., Great Britain, France, and Germany,

in

and has written numerous papers on technical subjects, which have appeared in scientific journals in Europe and America, and prepared articles upon similar topics for this CYCLOPEDIA. Some of his more important papers are the following: On Losses of Propelling Power in the PaddleWheel (1868), Steam- Engines of the French Navy (1868), H. B. M. Iron-clad Monarch (1870), Iron Manufactures Great Britain (1870), Experimental Steam-Boiler Explosions (1871), Report on Test-Trials of Steam-Boilers (1872), Traction-Engines and Road Locomotives (1871), Report on the Stevens Iron-clad Battery (1874), Efficiency of Furnaces burning Wet Fuel (1874). The Mechanical Engineer, his Preparation and his Work (1875), and a number of papers embodying accounts of original investigations of the strength and other properties of materials of construction. Among his numerous inventions are the magnesiumribbon lamp, a magnesium-burning signal apparatus, an autographic recording testing-machine, a new form of steam-engine governor, and an apparatus for determining

the value of lubricants.

Thurston (ROBERT LAWTON), b. at Portsmouth, R. I., Dec. 13, 1800; was engaged as early as 1821 in building steamers and machinery; founded the Providence Steam-Engine Co. and the firms of R. L. Thurston & Co., Thurston, Greene & Co., and Thurston, Gardner & Co., which were the first to build and introduce the "drop cut-off" expansive steam-engine, invented by F. E. Sickles and N. T. Greene. D. at Providence, R. I., in 1873.

Thy'ine Wood [§vλov vivov, the "wood of the Thuja, or yew improperly so called], a kind of wood mentioned in the Bible, is probably the arar or sandarach wood, the wood of Callitris quadrivalvis, a large tree of Barbary. This tree affords the resin called gum-sandarach, and its timber is considered imperishable by the Turks, who floor their mosques with its planks.

Thylacine. See THYLACINIDE.

Thylacin’idæ [from Thylacinus-dúλakos, “pouch "the name of one of the genera], or Dasyuridæ [from Dasyurus-daovs, "hairy," and ovpá, "tail"-the name of another genus], a family of mammals of the order Marsupialia and sub-order Dasyuromorphia, including the chief carnivorous mammals of Australasia. The form is diversiform in the several genera, the larger species much resembling a dog externally, others an opossum, and the small species simulating mice in appearance, although anatomically they differ but little from each other; the snout is dog-like or acutely pointed; the ears moderate or large; the tail is generally more or less long, and the feet have separate toes, four or five in number. The teeth are well developed, and simulate those of the placental carnivores (dogs, etc.), and are in considerable number-viz. M. †, P. M. or 3, C. †, I. 3 = 42-46; there is no such distinction between molars and premolars as in placental carnivores, only the last premolars (P. M. 3d) having deciduous predecessors; the molars have cusps connected more or less by sectorial ridges; the premolars are compressed, conical; the canines generally well developed and typical in form, and the incisors cylindroid and curved, and moderate or rather large. The skull superficially has much resemblance to that of a dog, but is of course radically different, and exhibits the typical marsupial modifications of the mammalian skeleton, and the small size of the cerebral cavity is indicated externally by the absence of inflation; the palate has a pair of large longitudinal vacuities between the true molar teeth of the respective sides. The stomach is simple, and there is no intestinal cæcum. The family is peculiar to the Australasian region, and its representatives there take the place in the economy of nature held by the placental carnivores and insectivores in other parts of the world. The species are quite numerous. They are primarily divisible into three groups, which may be provisionally considered as sub-families. These are (1) Thylacininæ, represented by one genus (Thylacinus) and two species in Van Diemen's Land; (2) Dasyurinæ, represented by two genera, Dasyurus and Diabolus (or Sarcophilus); and (3) Phascogalinæ, including the small insectivorous animals, represented, according to Krefft, by five genera and fourteen species-viz. Phascogale, with 2 species; Antechinus, with 6; Podabrus, with 4; Antechinomys, with 1; and Chatocereus, with 1. The most notable of all these are the Thylacini ( T. cynocephalus and T. breviceps), which are called "tigers" by the colonists of Tasmania, and the Diabolus ursinus, which rejoices, among the same people, in the significant name" devil:" the Thylacini are about the size of a large dog or a wolf, and are very powerful and savage animals; the Diabolus is little larger than a terrier dog, but much stouter about the head and shoulders, and has enormous strength in its jaws. The several large animals of the family are very destructive to the sheep of the Tasmanian colonists. THEODORE GILL.

Thyme [Gr. Ovμos], the name of certain non-American labiate half-shrubby plants of the genus Thymus. Two kinds are cultivated in gardens, the common, T. vulgaris, and the lemon-scented, a variety of T. serpyllum or wild thyme. Both plants afford good bee-pasture. The leaves are used for flavoring soups and forcemeats; the volatile oil is sold for oil of origanum, which it closely resembles.

Thyme, Oil of, a volatile oil obtained by the distillation of the herb Thymus vulgaris with water. It usually has a brownish-red color and a thickish consistency, although when freshly prepared it is nearly colorless and is mobile. It possesses a pleasant pungent odor and an aromatic taste, has a sp. gr. of about 0.9, and is but slightly soluble in water, although it dissolves in alcohol and in ether. Oil of thyme contains two hydrocarbons, a terpene (C10H16) and cymene (C10H14), and an oxygenated camphor, THYMOL (which see). These compounds are separated by submitting the oil to fractional distillation. When oil of thyme is distilled with a mixture of 8 parts of chloride of lime and 24 parts of water, chloroform is formed. J. P. BATTERSHALL.

Thym'ol (Thymylie Hydrate, Thymylic Alcohol, Thymylic Acid), (C10H140), is a homologue of phenol and an isomere of cymylic alcohol. It is obtained from the OIL OF THYME (see above), of which it is the oxygenated camphor or stearoptene, by distillation. Thymol forms crystalline rhomboidal plates, which have a weak odor and a peppery taste. It fuses at about 111° F. to a colorless liquid, which has a boiling-point of 446° F., and dissolves with difficulty in water, but easily in alcohol and in ether. By the action of chlorine, bromine, and nitric acid upon thymol, series of derivatives are formed.

J. P. BATTERSHALL.

Thy'mus [Gr. Ovμós, "soul"] Gland, a ductless gland, with no known function, located in the neck below the thyroid gland, and in the chest beneath the sternum, in the mediastinal space, as low as the fourth costal cartilage. It develops at the third month of foetal life, weighs half an ounce at birth, grows until the second year, attaining a length of two inches. Thereafter it atrophies, and at the fourteenth or sixteenth year is obliterated, or its site marked only by a few fibres and a small deposition of fat. It has abundant blood-vessels, nerves, and lymphatics, but endless research has failed to disclose its use in either the fœtal state or during childhood.

E. DARWIN HUDSON, JR. REVISED BY WILLARD PARKER. Thyroid Gland, a glandular structure consisting of two lateral lobes, with a connecting band or isthmus, situated on the anterior surface of the neck (hence its name, from Gr. Oupeós, a "shield," and eldos, "like") and attached to the sides of the larynx. The gland moves with the larynx in respiration and deglutition. The isthmus bridges across from the lower or basic portion of the lobules, and covers in its transit the front of the second and third tracheal rings. By this relation and its great vascularity it has an important surgical relation to the operation of tracheotomy. The gland is ductless, and its function is as yet unknown. It has an external fibrous coat, which gives off numerous internal partitions and bands, so that the gland consists of communicating cavities like a sponge. This sponge is the seat of the peculiar disease termed GOITRE (which see).

E. DARWIN HUDSON, JR. REVISED BY WILLARD PARKER. Thysanu'ra [from @voavos, “fringe," and ovpá, "tail"], a group of insects by some considered as a peculiar order or orders of the class, and by others as a sub-order of either the order Orthoptera or the order Neuroptera. They are wingless insects, with a hairy or scaly body, with the parts of the mouth variously and peculiarly developed, and generally more or less rudimentary, and which do not undergo a regular metamorphosis. The group embraces small insects, some of which are remarkable for the sculpture of the scales, which are common objects of microscopical examination. The formerly commonly-admitted families were Lepismida and Poduridæ, and to it was also later added a family, Campodeida or Campodeæ. Recently, however, Sir John Lubbock has completely remodelled the group, and divides it into two orders-viz. (I.) Thysanura (restricted), with three families, Lepismida, Campodeidæ, and Japygida; and (II.) Collembola (nearly coequal with the old family Poduridae), with the families Anuridæ, Lipurida, Poduridæ, Degeeriida, Synthuridæ, and Papiriida. (Consult Lubbock's Monograph of the Collembola and Thysanura, London, 1873. See also PODURA.) THEODORE GILL.

Ti, a liliaceous tree-like plant, Cordyline Ti, found in the Pacific Islands and in parts of Asia. Its leaves afford roofing for houses, food for cattle, and fibre for cloth. The sap yields sugar and a stimulating drink, while the roots, when baked, afford a valuable supply of food.

Tiahuanu'co, a group of interesting ruins in Bolivia, 12 miles from the shore of Lake Titicaca, on an eminence which may have once been an island in that lake. The elevation is 12,930 feet, and the surrounding country is a desolate and sterile plain. The ruins at this point are confessedly much older than the age of the Incas, but there seems to be no possible clue to their date. A marked character of the ruins is the use of enormous and finely-wrought stone blocks, in some instances clamped together with bronze. Mr. Squier believes that Tiahuanuco was never a city, but was built for a shrine or sacred place by some pre-historic race of men. The whole area is, however, very considerable.

Tia'ra [Gr. Tápa, a Persian head-dress], the papal crown, a cap of cloth of gold having three golden circlets, two silken embroidered pendants, and at the top a golden cross. It was at first a plain round cap (worn first by Damasus II.). The first crown or fillet was added before, or by, Nicholas I. (S58-867); the second, either by Nicholas II. (1059-61) or by Boniface VIII. (1294-1302); the third, either by Clement V. (1305-14) or by Urban V.

(1362-70).

Ti'ber [Lat. Tiberis], the most celebrated of Italian rivers, rises at the foot of Mount Aquilone, a spur projecting from the S. W. flank of the Apennines, in N. lat. 43° 45', W. lon. 12°, at the height of 1600 feet above the sea, drains a basin of about 6500 sq. m., and after a course of 220 miles, generally in a S. direction, though with many sinuosities, empties into the Mediterranean near Ostia, 27 miles below Rome, in N. lat. 41° 45'. The mean delivery of the Tiber is about 400 cubic yards per second; its smallest observed delivery is 215 cubic yards. It is navigable from the sea to Rome for vessels of 140 tons and with some difficulty 60 or 70 miles farther for vessels of 60 tons. The Romans kept the channel of the Tiber above Rome, up to the outlet of the Nera, about 100 miles from the sea, as well as those of the lower course of the Nera, the Chiana, and the Anio, always in a boatable condition, and employed them very largely for transportation; but at present those channels are little used for any form of navigation, except, on a small scale, for flotation of firewood and lumber. Up to Rome the bed of the Tiber may be considered an estuary, for at various points below Ponte Sisto the bottom of the river is from 30 to 20 feet below the level of the sea. The sedimentary deposits of the river have both raised its bed and lengthened its lower course since the days of ancient Rome, and hence it is not diffieult to understand that, though there is now generally depth of water only for small vessels, it was possible under the Empire for a ship to transport an obelisk weighing 400 tons from Egypt to a landing-place on the Tiber 3 miles below Rome. For the upper half of its course the current of the Tiber, though not torrential, is too rapid for navigation, and it is worth mentioning that above Rome it is not divided by a single noticeable island. Its waters are scarcely anywhere utilized as a motive-power or for irrigation, though they might be made largely available for both purposes. The epithet flarus ("yellow") applied to the Tiber by the Romans referred, no doubt, to the turbid appearance of its waters due to the quantity of sediment then, as now, borne down by them. Rozet calculated that the quantity of sediment annually deposited by the Tiber at its outlet had been for many centuries approximately constant, and sufficient to extend the coast seaward at the rate of a little less than 13 feet per year. Later observations show that at some points, at least, the rate of advance is greater. In general, we may say that there is no satisfactory proof of any considerable changes in the physical conditions of the Tiber, except those produced in its lower course by this accumulation of sedimentary deposit and by the creation or removal of artificial obstructions in its bed. We may add, however, that, according to the testimony of old writers, the Tiber was more frequently partially or completely frozen over in ancient than in modern times. The effects of the deposit of mineral and vegetable matter in the river-bed have been the same as similar causes have produced near the outlets of other rivers. The estuary, which originally formed the harbor of Rome, was so reduced in depth by the silt let fall by the river, as well as by sand rolled in from the sea, that it was found necessary in the days of the Empire to cut an emissary from a point considerably above Ostia to serve as a ship-canal to the Rea: and this is still the only navigable channel from the Mediterranean to Rome. Besides this, an artificial harbor, known as the port of Trajan, was filled up in the same way. and the river-silt united with the sea-sand both to form | shoals in what had been deep water, and to build up along the coast a vast range of banks rising above the water, behind which the overflow from the river spread out into shallow morasses of great extent, the miasmata from which

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not only render their immediate vicinity uninhabitable, but, as is commonly thought, are among the chief causes of the present insalubrity of Rome and the whole Campagna. The regulation of the Tiber involves the draining of these pestiferous marshes or the filling of them with the sediment brought down by the river, which some able engineers think sufficient in quantity to accomplish this great work in a relatively short period of time. To restore the Tiber to its ancient function as the great maritime approach to the capital of Italy the construction of an artificial harbor at or near its mouth is a necessity; and this, as recent works of the like sort elsewhere have shown, is not to be regarded as an undertaking technically formidable or extravagantly costly.

Great

Aside from historical associations, into which we cannot enter, the special interest of the Tiber arises from certain peculiarities in its régime, and from its importance as a source of danger to the city of Rome. Of these peculiarities the most remarkable is the provision made by nature for the disposal of the precipitation in its basin. The mean annual delivery of the river is computed to equal two-thirds of the downfall in its valley, the proportion being above the mean in dry, below it in humid years. Comparatively little of the precipitation is conveyed to the channel of the Tiber by direct superficial conduction, but a vast amount of the water of rains and snows is received into subterranean cavities or absorbed by the bibulous earth which covers much of the surface, and slowly conveyed by underground conduits into the channel of the river, or possibly, to some extent, into the sea. Lombardini estimates "the subterranean discharge of the Tiber" at not less than three-fourths of the total delivery. The result of this natural arrangement is that this river has no true low-water stage, and at Rome, as well as far above the city, it flows always with a strong full current, its lowest known discharge being, as we have already seen, 215 cubic yards per second, or more than one-half its mean volume. Its minimum, therefore, is little inferior to that of the Po, while the mean discharge of the latter river is more than five times as great as the average delivery of the Tiber. The renewed importance of Rome as the social and political capital of a great nation, now happily restored to no small share of its ancient dignity and power, is drawing greatlyincreased attention to the dangers which threaten the city from the inundations of the Tiber, and to the means by which those dangers may possibly be averted. floods have occurred in the Tiber at frequent intervals through the whole historic period, and some of the most ancient seem to have been almost as overwhelming and destructive as the most violent of modern times; but in general the data we possess respecting them are too vague to enable us to arrive at precise comparative results. Under the first emperors the diversion of some of the principal tributaries, and even of the main channel of the Tiber itself, was suggested as a remedy for the evil, and similar measures form a feature of several of the plans now under consideration. To this there are grave objections, and, so far as we know, there is but a single point in which all engineers agree; we mean the expediency of widening and straightening the channel at various points within and near the limits of the city-where by human encroachment or other causes it has been narrowed and made tortuous-and of removing the numerous artificial obstructions, chiefly piers and piles of old bridges, by which the flow of the current is retarded and the deposit of sedimentary matter greatly promoted. There is much difference of opinion in regard to the extent of the relief to be obtained by this measure, but it could hardly fail to be considerable, and some are of opinion that the increased velocity of the current would suffice to scour out the accumulated deposits of many centuries, lower the bed of the river to its ancient level, and render the construction of dikes or river-walls upon the banks, which most of the projects contemplate, quite superfluous. The question is complicated by doubts which have been suggested as to the stability of the coastlevel at the outlet of the Tiber; and some geologists believe that not only the immediate shores of the Tyrrhenian, but the whole Campagna far into the interior, are undergoing a secular elevation.

Contrary to the general rule, the overflows of the main tributaries of the Tiber are contemporaneous, not successive, but their flood-waves reach Rome not together, but at intervals of some hours, and high water at the city is oscillating. The approach of these waves may be known by telegraph, and consequently in a certain degree guarded against.

There is another point connected with the operations for securing the lower parts of the city and its environs from overflow by the waters of the Tiber which has not been very fully investigated. We mean the action of the W. wind, either indirectly retarding the flow of the stream by impinging