DERWENTWATER 331 DESCARTES Durham, and Cumberland, respectively, the last draining Derwentwater lake. Also a river in Tasmania. DERWENTWATER, or KESWICK LAKE, a beautiful lake in Cumberland, England, in the vale of Keswick. It is about 3 miles in leng-th and 1% in breadth, and stretches from Skiddaw on the N. to the hills of Borrowdale. Near the N. E, corner is the celebrated cas- cade of Lodore. Its waters are carried to the sea by the Derwent. DESAGUADERO ("channel" or "out- let"), the name of various waters in South America, of which the principal is the Rio Desaguadero in Bolivia, empty- ing its waters into Lake Aullagas. Also a river in the Argentine Confederation flowing into Lake Bevedero Grande, and separating the provinces of San Luis and Mendoza. DESAIX DE VEYGOUX, LOUIS CHARLES ANTOINE (deza' de va-go), a French general; born in Auvergne, Aug. 17, 1768. In the early part of the Revolution he became aide-de-camp to General Custine, and was severely wounded at the battle of Lauterberg, but kept the field. Named successively general of brigade and of division, he contributed greatly, by his talents, to the success of the famous retreat of Moreau from Germany. He afterward defended the bridge and fort of Kehl for two months against the Austrian army with great bravery, and was wounded. He served with Bonaparte in Egypt, where he distinguished himself greatly, and was appointed governor of the upper part of the country. He completely sub- dued Upper Egypt, and received, as a testimony of admiration, from Bona- parte, a sword. He was obliged, how- ever, in 1800, to sign the unfavorable treaty of El Arish with the Turks and English, and on his way to France, was captured by Lord Keith as a prisoner of war. He afterward obtained his parole, and went to France. He once more fought under the banner of Bonaparte in Italy, but was killed at the battle of Marengo, June 14, 1800. DESCANT, the addition of a part or parts to a tenor or subject. This art, the forerunner of modern counterpoint and harmony, grew out of the still ear- lier art of diaphony or the organum. It may be said to have come into existence at the end of the 11th or beginning of the 12th century. Originally, as had been previously the case with diaphony, it consisted of two parts only, but later in its life developed into motetts and various other forms of composition. The real difference between diaphony and descant seems to have been that the for- mer was rarely, if ever, more compli- cated than note against note, whereas descant made use of the various pro- portionate values of notes. Double des- cant is where the parts are contrived in such a manner that the treble may be made the bass, and the bass the treble. DESCARTES, RENE (da-karf), a French philosopher and mathematician^ with whom the modern or new philoso- phy is often considered as beginning; born in La Haye, in Touraine, March 31, 1596. He was educated at the Jesuit College of La Fleche, where he showed great talent. He entered the military profession and cerved in Holland and in Bavaria. In 1621 he left the army, and RENB DESCARTES after a variety of travels finally settled in Holland, and devoted himself to phil- osophical inquiries. Descartes, seeing the errors and inconsistencies in which other philosophers had involved them- selves, determined to build up a system anew for himself, and resolving to ac- cept as true only what could stand the test of reason. There was one thing that he could not doubt or divest himself of the belief of, and that was the exist- ence of himself as a thinking being, and this ultimate certainty he expressed in the celebrated phrase, "Cogito, ergo sum" (I think, therefore I am). Start- ing from this point, Descartes found the same kind of certainty in such propo- sitions as these: that the thinking being
