DAT 



DAU 



promote the method of resolution and 

 analysis. In algebra, the given quanti- 

 ties or data, are expressed by the first 

 letters of the alphabet, and the unknown 

 quantities by the last letters; thus, if the 

 problem be, from the sum and product of 

 two quantities given, to find the quanti- 

 ties themselves, the quantities are re- 

 presented by yand z; and y-J-:=a, the 

 sum given, and t/z=b, the product given. 

 From the primary use of the word data 

 in mathematics, it has been transplanted 

 into other arts, where it expresses any 

 quantity, which, for the sake of a present 

 calculation, is assumed as true, without 

 stopping to give a proof of it, called also 

 the given quantity, number, or power. 

 Hence also such things as are known are 

 now frequently by physical writers de- 

 nominated data. 



DATE, in law, is the description of the 

 day, month, year of our Lord, and year 

 of the reign of the King, in which a deed 

 or other writing was made. Anciently, 

 deeds had no dates but only of the month 

 and year, and now, if in the date of any 

 deed the year of our Lord is right, though 

 the year of the King's r.eign be wrong, it 

 shall not hurt the same. A deed is good, 

 though it has no date of the day, or if 

 that be mistaken, or though it con- 

 tains an impossible date ; but then he 

 that pleads such a deed must set forth 

 the time when it was delivered : for eve- 

 ry deed or writing has a date in law, and 

 that is the day of the delivery ; and where 

 there is none, a plaintiff', it is said, may 

 count it of any date. 



In writings of importance, the date 

 should be written in words at length. 



In letters, it is usually written in figures. 



An ante-date, is a date prior to the real 

 time when the instrument was signed. 



A post-date, is that posterior to the real 

 time when the instrument was passed. 



DATE. See PHCENIX. 



DATISCA, in botany, a genus of the 

 Dioecia Dodecandria class and order. 

 Essential character: male, calyx five- 

 leaved ; corolla none ; anthers sessile, 

 long, fifteen ; female, calyx two-toothed ; 

 corolla none ; styles three ; capsule tri- 

 angular, three-horned, one-celled, per- 

 vious, many-seeded, inferior. There are 

 two species; viz. D. cannabina, smooth 

 stalked bastard hemp, found in Candia; 

 and I), hirta, rough stalked bastard hemp, 

 a native. of Pennsylvania. These are tall 

 upright herbs, with alternate unequally 

 pinnate leaves. The flowers are in spik- 

 ed racemes, axillary, with one bracte ; 



the flower is apetalous ; fruit is inferior, 

 and contains many seeds. 



DAT1SI, in logic, a mode of syllogisms 

 in the third figure, wherein the major is 

 an universal affirmative, and the minor 

 and conclusion particular affirmative pro- 

 positions. For example, 



DA- All who serve God are kings ; 

 TI- Some who serve God are poor ; 

 si. Therefore some who are poor are 

 kings. 



DATURA, in botany, English thorn- 

 apple, a genus of the Pentandria Mono- 

 gynia class and order. Natural order of 

 Luridae. Solaneie, Jussieu. Essential cha- 

 racter : corolla funnel-form, plaited ; 

 calyx tubular, angular, deciduous ; cap- 

 sule four- valved. There are eight species; 

 these are all herbs, and annual, excepting 

 one ; the flowers and brandies are soli- 

 tary, they have a strong narcotic smell ; 

 most of the species, coming from hot 

 countries, require the protection of a 

 stove or glass case. 



DAVELLIA, in botany, a genus of the 

 Cryptogamia Filices. Fructifica in round- 

 ish distinct <k>ts near the margin; in- 

 voluce membraneous from the surface, 

 half-hooded, distinct, somewhat truncate, 

 opening toward the margin. There are 

 eighteen species. 



DAVIESIA, in botany, a genus of the 

 Decandria Monogyliia class and order. 

 Calyx angular, simple, five-cleft ; corolla 

 papilionaceous; stigma simple, acute; 

 legume compressed, one-seeded. One 

 species, -D. australasia, described by Dr. 

 Smith in the fourth Vol. of the "Linn. 

 Transactions." 



DAVIT, in a ship, that short piece of 

 timber, with a notch at one end, wherein, 

 by a strap, hangs the fish-block. The 

 use of this block is to help up the fluke 

 of the anchor, and to fasten it at the 

 ship's bow, or loof. The davit is shiftable 

 from one side of the ship to the other, as 

 there is occasion. There is also a small 

 davit in the ship's boat, that is set over 

 her head with a shiver, in which is 

 brought the buoy rope, wherewith to 

 weigh the anchor; it is made fast to the 

 carlings in the boat's bow. 



DAUCUS, in botany, English carrot, a 

 genus oi the Pentandria Digynia class and 

 order. Natural order of Umbellatx. Es- 

 sential character: corolla subradiate, all 

 hermaphrodite ; fruit hispid, with hairs. 

 There are seven species, of which we 

 shall mention D. carota, wild carrot, or 



