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 278 DRYING OILS principal editions of his works are his dramas (6 vols. 12mo, London, 1718) ; miscellaneous works (4 vols., 1760); prose works, edited by Malone (4 vols. 8vo, 1800) ; and a complete edi- tion of all his writings, with notes and a memoir by Sir Walter Scott (18 vols. 8vo, Edinburgh, 1808). The "Fables," ornamented with en- gravings after the designs of Lady Diana Beau- clerc, were published in folio (London, 1797). The life of Dryden has been written by Dr. Johnson, and forms the most eloquent and dis- criminating of all his " Lives of the Poets." DRYING OILS, A number of vegetable oils, as linseed, nut, poppy seed, and some others, exhibit a strong tendency to absorb oxygen from the air, and, when exposed in thin layers, to dry into a resinous kind of varnish. The addition of a small quantity of oxide of lead greatly accelerates the process. These oils are consequently well suited for mixing with color- ing matters to form paint for wood work. They impart no color of their own, and serve to bind and secure the color to the wood, which they also aid to protect by their resinous coat. The so-called greasy oils have no such tendency to dry by exposure, but become rancid. DRY ROT, an affection of timber which is often very rapidly destructive to ships, and to damp, ill ventilated houses. A general char- acteristic is the development of fungi, especial- ly the polyporiis hylridus, thelepora puteana, and merulius lachrymans, and also of lower forms. These growths are at the same time accompanied, although not necessarily in a cor- responding degree, by a slow decay, akin to eremacausis. The only practical means of ar- resting dry rot is to expose the fibres of the timber to the action of certain metallic salts, or other substances which have the power of de- priving the fungi of life and of so fixing the or- ganic constituents of the wood as to prevent their oxidation. An ordinary process, long practised, is that of kyanizing (so called from being extensively employed by Mr. Kyan, at the suggestion of Sir Humphry Davy), which consists in steeping the wood in a solution of corrosive sublimate. The success of this pro- cess has been questioned, and the use of other salts has been introduced. Sir William Burnet has proposed chloride of zinc for preserving not only wood, but also canvas and cordage. Carbolic acid has been successfully employed, as also creosote, gas tar, and other coal pro- ducts. Sulphate of iron and calcium chloride, in Payne's process, are much used in Great Britain. This process is as follows: Into a large cylinder several pieces of timber are in- troduced ; steam is forced in, by which most of the air is driven out; then a cold solution of sulphate of iron is let in, which, condensing the steam, produces a partial vacuum, which is completed by the air pump. The liquid flows into the pores, and is further forced into them by pressure. The iron solution is then allowed to flow off, when steam is again introduced and applied until all or nearly all moisture in DUANE the timber is vaporized. A cold solution of calcium chloride is then allowed to flow in; a vacuum is again produced, and the calcium salt enters the pores, and forms, by double de- composition with the iron salt, ferric chloride and sulphate of lime, or gypsum. A variation of the process has been used to stain and pre- pare common woods in imitation of rarer and more durable kinds. DRY TORTUGAS, a group of ten islets or keys forming part of Monroe co., Florida, at the ex- tremity of the Florida Keys, 120 m. W. S. W. of Cape Sable, the S. point of the state ; pop. in 1870, 237. They lie just within the gulf of Mexico, in about lat. 24 37' N., Ion. 83 W. The islets, which are of coral formation, are low and barren except where partly covered with mangrove bushes. On Bush or Garden Key is Fort Jefferson, which in 1870 was gar- risoned by 98 men. A lighthouse has been erected on the same islet. During the civil war the fort was used as a penal station for confederate prisoners, and in 1865 O'Laughlin, Spangler, Arnold, and Mudd, found guilty by a military commission of participation in the assassination of President Lincoln, were sent thither to serve out their terms of imprison- ment, but were pardoned by President John- son, except O'Laughlin, who died there. Pris- oners under sentence of court martial are occa- sionally confined at Fort Jefferson. DUALLINE. See EXPLOSIVES. DUANE, William, an American politician and journalist, born near Lake Champlain, N. Y., in 1760, died in Philadelphia, Nov. 24, 1835. At the age of 11 he was taken by his mother to her native country, Ireland, and liberally educated ; but having forfeited her protection by marrying against her will at the age of 19, he learned the art of printing, and in 1784 went to India. There he amassed property rapidly, and became editor of an Indian journal entitled " The World." Having taken sides against the local government in a dispute with some of its troops, he was seized and sent to England, and his large fortune was confiscated. After in vain petitioning parliament and the East India company for redress, he became editor of the " General Advertiser," siding in politics with the party of Home Tooke and others. In 1795 he returned to America, and became editor of the " Aurora," published at Philadelphia, making it the most influential organ of the democratic party. The change of the seat of government to Washington caused the "Aurora" to decline in political impor- tance. Duane retired from its editorship in 1822, and travelled through the republics of South America. On his return he published an account of these travels, and was appointed prothonotary of the supreme court of Pennsyl- vania for the eastern district, an office which he retained until his death. He served in the war of 1812, and published a "Military Dic- tionary " (Philadelphia, 1810), and a " Hand- book for Riflemen " (1813).