X-BAYS. tJ'JT X Y Z CORRESPONDENCE. other abdominal organs and viscera. In the pelvic cavity, lueasureinents of the uterus may be made; extra-uterine pregnancy may be diafj;nused. Therapeuticallj', the X-ray is serviceable in the treatment of lupus, eczema, syphilitic lesions, nu'vus, sj'cosis, i'avus, acne, and psoriasis. In many cases of new growths, such as cancer (both carcinoma and epithelioma) and sarcoma, it has produced amelioration and actual cure. It is claimed by those in a position to know that the X-ray ofl'ers far greater possibilities and capa- bilities than Finsen's light. (See Puotgtuerai'Y.) Pain and itcliing may be permanently removed by X-ray treatment in certain cases. In surgery, the Runtgen rays were first used to detect the position or presence of foreign bodies, such as bullets, and to recognize fractures. Development of the methods of their application has led to their successful use in diseases of bone, rachitis, subperiosteal abscess, dental and ortliopirdic surgery, and the detection of calculi. Much has been added to the anatomist's knowl- edge of the skeleton, especially of the joints. The value of X-rays in cases of fracture remains preeminent, both to confirm diagnosis and to de- cide if a fracture has been properly reduced, after it has been put into a retaining apparatus. In mili- tary surgery, both English and American authori- ties earnestly advocate the use of X-ray appa- ratus in the general base hospital or in the hos- pital ship. It is also suggested that the X-ray is a valuable adjunct in life insurance examina- tions, and also in medico-legal cases. In the lat- ter, radiographs, it must be remembered, can be interpreted only by those who are skilled in the use of the Rijntgen ray and in the reading of the jiictures. No jury is competent to pass upon the value of a radiograph. Consult Williams, The Roentgen Rays in Medicine and Surgery (New York, 1903). XUREL. A fish. See Jurel. XYLENE (from Gk. ?uok, xylon, wood), or Xylol, CsHi„. A name applied in chemistry to three compounds of carbon and hydrogen, simi- lar to benzene and found along with it in coal- tar (q.v.). The three xylenes have the same chemical composition ; the ditTerences in their physical and chemical properties are due to dif- ferences in the arrangement of the atoms within their molecules. XYLOGRAPHY. See Wood-Engraving. XYLOi'DIN (from xyloid. from Gk. |i«ofi5^!, xiiloeidcK, like wood, from JiiXof, xyloii, wood -j- ciooi, cidi)S, form). A substance produced by the action of nitric acid on starch. It is a constitu- ent of certain explosives. XYLOPHONE (from Gk. liiXoi-, xylon, wood + Owvfi, plioiic, sound, voice). A musical instru- ment composed of a diatonically graduated series of wooden keys arranged horizontally upon two cords. It has a compass of about two octaves, and is played by two little mallets held in the musician's liands. the principle being the same as that of the musical glasses. It is a very an- cient and widely used instrument, traces of it being found in Europe, Asia, and America. XYS'TUS. The name of two early popes, taken as ei|uivalent to Sixtus (q.v.), so that the later popes named Sixtus are numbered con- secutively from them. X Y Z CORRESPONDENCE. In American history, the name applied to dispatches sent to the L nitcd States Government by tliree special envoys in France in 171)7-1)8. In May, 171)7, C. C. Pinckne}', .John -Marshall, and KIbridgc Gerry were named as conunissioners to the French Ke- public, between which and the United States strained relations then prevailed. The commis- sion arrived in Paris in October, and attempted to open negotiations with the Directory. Ollicial recognition was refu.sed them; but the secre- tary of Talleyrand, French Minister of Foreign Afi'airs, informed the commissioners that, al- though the Directory was much incensed by cer- tain passages in the President's recent message, some agents would be sent to them to conduct negotiations. On October 18th one of these agents, M. Hottinguer (X), informed Pinekney that in order to gain the favor of the Directory, a 'loan' of 1,200,000 livres would be necessary. A few d.iys later two other agents, M. Bellamy (Y) and M. Hauteval (Z), engaged in the negotia- tions, and it was than explained that if the United States would buy at par certain stock amounting to .32,000.000 florins (its market value was about half that sum), which France had extorted from the Dutch Republic, the transaction would be considered as equivalent to a loan. The envoys were also given to understand that unless money was forthcoming nothing could be accomplished and a war might result. The commissioners re- jected the proposals, and, though they remained, accomplished nothing. Gerry, the only Repub- lican member of the commission, remained for some time after the departure of Marshall and Pinekney and thereby incurred much criticism. (See Gerry, Elbridge.) After seeing the dis- patches sent home by the commissioners. President Adams on March 10, 1798, informed Congress that no terms "compatible with the safety, the honor, or the es.sential interests of the nation" could be obtained. At the request of Congress copies of the dispatches were communicated to that body. In the copies, however, the letters X, Y, and Z were substituted for the names of the French agents, hence the name X ' Z Correspondence. The revelation contained in the dispatches caused a great sensation. All parties joined in making preparations for war, which indeed did break out upon the sea. As a resiilt of the aft'air the Presi- dent and his party were for a time exceedingly popular, hut soon lost public favor through the Alien and Sedition acts and through the Presi- dent's sending to France a new commission, com- posed of Chief Justice Ellsworth, William R. Davis, and William Vans Murray. This com- mission, however, in September, 1800, arranged a convention that once more put the two nations upon friendly terms. The so-called X Y Z Corresjiondence may he found in American fitntr Papers. Foreign Relations, vol. ii. (Wash- ington, 1832). Consult: Morse, John Adams (Boston, 188.5) ; Schouler, History of the United f<tates (New York, new ed. 1899) : and C. F. Adams, Works of John Adams (Boston, 1850-56).
