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 TULTCHA TUNGSTEN 29 TFLTCH1, or Tultsha (anc. jfigissus), a town of Bulgaria, on the right bank of the Danube, 6 m. above the junction of its Sulina and St. George's arms, 12 m. S. S. W. of Ismail, and 45 m. W. of Sulina ; pop. variously estimated between 13,000 and 20,000. It is a port of considerable commercial importance. The for- mer fortress was damaged by the Russians in 1789 and 1791, and utterly destroyed in 1828, after which the present town was laid out. It was occupied by the Russians during the spring of 1854. Darius crossed the Danube in the vicinity of ancient JEgissus in his expedi- tion against the Scythians. TUMOR (Lat. tumere, to swell), an excessive growth of tissue confined to a limited region, not inflammatory. Tumors are described as "benign" or "malignant," as "homologous" or " heterologous." A benign tumor is one which does not, except by its mechanical action, interfere with life, and has generally no tendency to recur after removal. A malig- nant tumor is one produced by or inducing a constitutional taint, and usually reappearing after removal. A homologous tumor is one the structure of which is like tissues normally existing in the body. A heterologous tumor is one composed of tissues unlike to those nor- mally present. Though a foundation of truth lies in this nomenclature of sufficient strength to have misled most physicians, our present knowledge of the histology and clinical his- tories of these growths has clearly shown that these distinctions are erroneous. The extremes are well marked, but the boundary line is ir- regular or confused. To what the growth of tumors can be ascribed is undetermined. That it is due to a perverted nutrition is certain, but how or why cannot be explained. The ex- citing cause is always mechanical, either from without or within the body ; the predisposing cause, apart from heredity or mal-nutrition, specific or of other character, is obscure. With such a knowledge of tumors, an accurate clas- sification is impossible, but one can be made which will greatly assist in the diagnosis, prog- nosis, and treatment of these growths, and also in the examination of their minute struc- tures, viz. : 1, cystic tumors ; 2, those made up of simple or composite tissues, aggregated or arranged as usually found in the adult body; 3, those made up of simple tissues, aggregated or arranged in a manner deviating widely from the normal, the cell element largely predomi- nating. A cystic tumor is one having a limit- ing membrane which exists normally, or is formed by a condensation of surrounding tis- sue, or is a production of new tissue. The contents may be fluid or solid. Housemaids' knee is an example of a fluid cystic tumor, the limiting membrane of which exists normally. The sebaceous tumor of the scalp is an ex- ample of one which is solid, produced by an obstruction in its duct to the secretion of a gland. A blow on the head may cause an ef- fusion of blood beneath the scalp, which, by its outward pressure and irritation, can produce and excite the formation of a cyst wall. In this class will be comprised most ovarian tu- mors, kidney cysts, congenital tumors contain- ing hair, &c. To the second class belong all tumors of a fibrous, fatty, or cartilaginous nature, either alone or combined, and those made -up of composite tissues, such as the vas- cular and glandular tumors. To the third class belong such growths as consist mainly of cells, or of cells mingled with other tissues in an ir- regular and abnormal manner: tubercle, sar- coma, cancer, &c. Making use of the terms employed in the nomenclature mentioned above, tumors in the first and second classes are homologous and generally benign; those in the third class are heterologous and as a rule malignant. The chief interest, as regards prognosis, centres upon tumors of the third class. Opinion is divided as to whether cancer, using this term in its common signification, and taking this member of the class as the most important surgically, is primarily a local disease affecting the constitution only secon- darily, or whether it is merely the local mani- festation of a preexisting constitutional taint. TUNBRIDGE, or Tonbridge, a market town of Kent, England, on the Tun, near its entrance into the Medway, 11 m. S. W. of Maidstone ; pop. in 1871, 8>209. It consists for the most part of one long and well built street, and contains six churches, an endowed grammar school lately rebuilt, and several literary and charitable institutions. There are ruins of a gateway flanked by round towers, once be- longing to the castle built by the first earl of Clare and Hertford in the llth century. The refectory of a priory founded by the same earl is still standing. Tunbridge has manufactures of gunpowder and fancy wooden wares, and a considerable trade in coal and lumber. TUNBR1DGE WELLS, a market town of Kent and Sussex, England, in a beautiful country, 15 m. S. W. of Maidstone ; pop. in 1871, 19,410. It is a fashionable watering place, and consists chiefly of clusters of houses on detached emi- nences, and of a parade paved with pantiles in antique style, and lined with fine trees on one side, and on the other with assembly rooms, libraries, and shops. The surrounding country abounds in mineral springs. The one to which the place owes its origin is a light pure cha- lybeate, and the water is considered remark- ably efficacious in cases of weak digestion. TUNGSTEN (Swed. tung, heavy, and sten, stone), a metal existing in the form of an acid combined with lime in the mineral scheelite or tungstate of lime, and also combined with iron and manganese in the mineral wolfram. Tung- stic acid was discovered by Scheele in 1781, and metallic tungsten two years later by the brothers D'Elhujar. Its German name Wol- framium gives its symbol, W. It is obtained as a heavy iron-gray metal, very hard and dif- ficult of fusion, and of the high specific gravity 17'6, by intensely heating tungstic acid made