Page:The American Cyclopædia (1879) Volume IV.djvu/395

 CHEST CHESTER 387 II. BY LOTD. WHITE. K. at Q. B. 7th, Q. at Q. Kt. 2d, K. at K. Kt. 8th, Kt. at K. B. 2d. BLACK. K. at K. Kt. 7th, Ps. at K. Kt. 6th and K. B. 5th. White to play and mate in three moves. In the numerous legends and curious anec- dotes which adorn its annals, in its venerable nomenclature, which has been transmitted through all the changes of language, from the earliest tongues of the Indo-European stock to the latest, in its singular combination of idle amusement and mental toil, and in the fascina- tion which it has ever exercised over its vo- taries, chess forms a remarkable chapter in the history of the world. Monarchs like Haroun al- Rashid, Charlemagne, Tamerlane, Charles XII., Frederick the Great, and Napoleon I., and phi- losophers like Leibnitz, Voltaire, Rousseau, and Franklin, have found delight in its study and pleasure in its practice. Alone among games its use has been sanctioned by the priesthood of all beliefs, Catholic, Protestant, Buddhist, and Moslem. Erudite writers have illustrated its history, and acute intellects have elaborated its theory, until it has at length become the subject of a large and pleasant literature. CHEST. The human body being commonly divided into head, trunk, and limbs, these again are subdivided into head and face, chest and abdomen, upper and lower limbs. The chest, then, is the upper portion of the trunk, to which are attached externally the breasts in front, and the arms and shoulders laterally and posteriorly, and the cavity of which contains internally the heart and lungs. The walls of the chest are composed mainly of the ribs and the muscles pertaining to the ribs ; the dorsal portion of the spinal column completes the walls of the chest behind, and the sternum completes them in front. The neck connects the chest with the head, and the midriff or dia- phragm divides internally the cavity of the chest from that of the abdomen. The upper portion of the chest, between the spine, first ribs, and the sternum, forms an aperture through which the trachea passes into the chest, and the great arteries and veins of the head, neck, and arms pass out of the chest from the heart and main vessels. The spaces between these vessels and the bones are occupied by the oesophagus, by certain nerves and muscles, and by what is termed cellular or connective tissue. The whole chest thus forms a cavity closed on all sides, but allowing the passage of certain tubes or vessels through the upper and the lower portion of its walls, such as the trachea, oesophagus, blood vessels, nerves, &c. This cavity contains within it three subordinate cavities, the middle one containing the heart sheathed in the pericardium, and the two cav- ities at the sides containing the lungs, sheathed by the pleural serous membranes, and called the pleural cavities. Each lung is suspended, as it were, in its appropriate cavity by its bronchus from the trachea, and by the trunks of its pulmonary artery and veins, which, bound together by connective tissue, form what is called the root of the lung. For the sake of easy motion, the wall of the cavity is lined, and the surface of the lung is covered by a smooth membrane called the pleura, the con- tiguous surfaces of which are moistened with serous fluid to prevent friction from alternate respiratory motions of the chest and lungs. The pleural cavities being completely closed on all sides, no air can enter them, but the lung in each cavity communicates. with the external air by means of its bronchial tubes leading to the trachea and larynx, through which the air passes, not into the cavity of the chest, but into the interior of the lung. In their medium state, the lungs of a person of ordinary size and in good health contain about 200 cubic inches of air. In easy breathing, about 20 cubic inches is drawn into them at each inspiration ; but this may vary considerably, according to the efforts made in muscular exertion, or du- ring singing, or before coughing. The limit which the rigidity of the walls of the chest seta to the elastic collapse of the lungs is never reached in ordinary respiration, and the lungs accordingly are never entirely emptied of air. CHESTER. I. A S. E. county of Pennsylva- nia, bounded S. and S. E. by Maryland and Delaware, N". E. by the Schuylkill river, W. by Octorara creek, and drained by French, Elk, and the sources of Brandywine creeks ; area, 738 sq. m. ; pop. in 1870, 77,805. It formed one of the three original counties of the province established by William Penn in 1682. The surface is much diversified. A rich lime- stone valley about 2 m. wide, extending from the Schuylkill to the Susquehanna, divides the county into two nearly equal parts, of which the southern is rolling or gently undulating, with rich deposits of chromate of iron, valuable porcelain clay, and gneiss ; while the northern is rugged, and contains gneiss, sandstone, red shale, copper, and abundance of lead and iron. The N". W. boundary is formed by a low ridge called Welsh mountain. Besides the minerals above mentioned, there are silver, zinc, titani- um, zircon, agate, chalcedony, amethyst, sap- phire, and beryl. The valley yields excellent limestone and marble. Agriculture is carried to great perfection. The county is traversed by the Pennsylvania Central and Waynes- borough branch, the West Chester and Phila- delphia, and the West Chester railroads, and by the Philadelphia and Baltimore Central railroad. The Philadelphia and Reading rail- road passes along its N". E. border. Valley Forge and Paoli, of revolutionary fame, are in this county, which also contains the birthplace of Gen. Anthony Wayne. The chief produc- tions in 1870 were 753,803 bushels of wheat, 1,540,125 of Indian corn, 1,034,430 of oats, 404,363 of potatoes, 114,898 tons of hay, 2,848,243 Ibs. of butter, and 31,776 of wool. There were 14,086 horses, 32,670 milch cows, 21,916 other cattle, 13,069 sheep, and 28,165 swine. There were 32 manufactories of car-