TUMOR. 533 TUNGUS. lyniphatie glands ma}- Ijc excised. Caustics are rarely successful. Quacks are prone to diagnose simple fibromata as cancers, and then cure them with caustics. The use of light has proved of increasing efficacy in the removal of malignant growths, and it is confidently expected that Fin- sen's light or the X-ray will become a substitute for the knife. See Phototherapy; X-Ray. Epithelioma, or 'epithelial cancer,' is often diagnosed from other tumors with much diffi- culty. The following points are of assistance: ( 1 ) It occurs almost invariably on nuico-cutane- ous surfaces. (2) It ulcerates very early. (3i Ul- ceration follows upon the new growth so rapidly that it seems to spread hj ulceration. (4) It arises after local irritation. (5) There is no metastasis to internal organs in the vast ma- jority of cases of epithelioma. It is common in middle-aged or elderly people. Epithelioma of the lip, an ordinary form, follows smoking (and hence is called 'smokers' cancer'), or irri- tation from a broken tooth, intermittent pressure of some article lield in the moutli. as a painter's dust-brush, etc. It commences generally as a small wart or flat tubercle with hard edges and a suppurating surface. Ulceration spreads, the edges of the ulcer being hard and tliickened. Jt scabs over and the scab scales oH' again. Glands in the neck become enlarged, and the muscles of the face become involved. Early excision of a lib- eral V-shaped section of the lip, the larger part being remoxed from the vermilion border, and the cut edges being stitclied together afterward, is the proper treatment. Freqiientl.y from three to seven j'ears pass before recurrence in the scar follows, or recurrence may never take place. In some instances the ligature, or the ^craseur, or caustic is preferable. The X-ray or Finsen's light may also .succeed. Consult: Delafield and Prudden, Handbook of Puthological Anaiomy niid Bistologi/ (New York, 1901); Virohow. Die kninkhaflcn Geschwiilnfe (Berlin, 1900) ; Park, Surgery by American Au- tliors (Philadelphia, 1901). TTJNA. See Prickly Peab. TTJN'BRIDGE. A market town in Kent, England, on the Medway, 27 miles southeast of London (Map: England, G 5). The manufac- ture of toys, boxes, and articles of wood in Tun- bridge ware, a mosaic veneer of beech, holly, etc., is a specialty. A notable feature is the remains of a inediiEval castle, which stands on the Med- way, near the entrance of the town. It has a noble gate tower of great size, richly orna- mented. Among other structures are the parish church, a large restored building, and the gram- mar school, founded in IS.?.?, with an endowment of £5.500 a year. Population, in 1901, 12.736. TXJNBRIDGE 'WELLS. An English inland watering-place, on the liorder of Kent and Sus- sex, five miles south of Tunbridge (Map: Eng- land. G 5). Its picturesque surroundings, healthful climate, and chalybeate springs have rendered it a fashionable resort since the seven- teenth century. It has a large trade in the vari- ous articles made of Tunliridge ware. The wells, discovered in 1006, are situated at the head of a promenade called the Pantiles. The princijial buildings are the corn exchange, town hall, public hall, sanatorium, and mechanics' insti- tute. The town was incorporated in 1889: it owns an excellent water supply, sewage farms, electric lighting works, and a cemetery. Popu- lation, in 1891, 29,254; in 1901, 33,388. Consult Ward, Nurrry uiid tiuntit'x (London, 1897). TUNDRA (Russ., from Finnish tuntur, marshy plain). The name given to regions in Arctic America, Asia, and Europe, characterized as swamps of bog moss on which the snow- white reindeer moss and various kinds of lichens flourish. A luxuriant growth of flower- ing plants is ahso a cliaraeteristic of some of the tundras. The tundras are visited by wild birds in the summer, at which time they are inac- cessible morasses, but in the winter they may be readily crossed. The soil at a depth of one or two feet below the surface remains frozen throughout the .year, and the thickness of the vegetable growth increases annually, so that the surface of the tundra slowly rises. The rivers that flow tlirough the tundras expose a great depth of layers of ice and frozen soil, in which the bones of the mammoth, the rhinoceros, and other extinct animals are sometimes found. See Alaska ; Siberia. TUNGSTEN (Swed. tungsten, from tung, heavy -)- sicn, stone), or Wolfram. A metallic element discovered by d'Elhujar in 1781. It is not found native, but occurs as the tungstate of iron and manganese in the mineral icolframite, as the calcium tungstate or seheelite. as the tri- oxide or icolfram ochre, and in small quantifies in other rare minerals. The metal itself may be prepared by heating the trioxide with carlion or in a current of hydrogen, or by heating the chloride in vapor of sodium. Tungsten (symbol, W (wolfram); atomic weight, 184.83) is a bright, steel-gray, hard, brittle, crystalline substance, with a specific gravit_y of 19.12. It melts only at the strongest white heat. It is chiefly used to increase the hardness and tenacity of steel and thus im- prove it as a material for hard tools. Tungsten combines with oxygen to form a dioxide and a trioxide, the latter of which unites with water to form tungstic acid, which in turn combines with bases to form a series of salts called tiiijgstatcx. Of these the sodium tungstate is sometimes used to replace sodium stannate as a mordant in dyeing and printing. Fibres dipped in a solution of this salt are rendered fireproof. TUNGSTITE. A mineral tungsten trioxide crystallized in the orthorhombic system. It is of a bright-yellow or green color. It is found with other tungsten minerals in Cornwall and Cumberland, England, and as a coating or in cavities in Monroe, Conn., and Cabarrus County, N. C. The preparation of artificial crystals of this mineral has been reported. TUNGUS, tiin'guz. A group of peoples of the I'ral-Altaic or .Sihiric stock embracing the tribes of the Tungus proper, whose territory ex- tends from the Yenisei to the Pacific and from the Arctic Ocean as far south as latitude 40°, and the Manchus. The Tungus proper consist of the northern Tungus, comprising the Olchas or Man- gun, at the mouth of the Amur, the Oroks in the northern part of the island of Saghalien, the Orochons, on both banks of the Amur, the Manegers, on the left bank of the Amur east of the Orochons, and the Olennyig or Rein- deer Tungus ; the southern Tungus, including
