DRY 



DUC 



ble will grow in them. The joists being 

 sawed on to theirproper lengths, and ful- 

 ly prepared, they and their plates were 

 well charred, and laid upon the ashes ; 

 particular directions being given, that no 

 scantlingor board might be cut or planed 

 in the place, lest any dust or shavings 

 might drop among the ashes. The 

 flooring-boards being very dry, he caused 

 them to be laid close, to prevent the dust 

 getting down, which, perhaps, in the 

 course of time, might bring on vegeta- 

 tion. The framing of the closet was then 

 fixed up, having all the lower pannels let 

 in, to be fastened with buttons only, so 

 that, if any vegetation should arise, the 

 pannels might with ease be taken out and 

 examined. In some situations, it might 

 be expedient and necessary to t:>ke out a 

 greater depth of earth ; and where ashes 

 can be had from a foundry, they may be 

 substituted for those of anchor-smiths; 

 but house ashes are by no means to be 

 depended upon. At the expiration of 

 seven years from the period of making 

 this experiment the wainscot was remov- 

 ed, and the flooring-boards also taken up, 

 when they were found entirely free from 

 any appearance of the rot: two pieces of 

 wood (yellow fir) which had been driven 

 into the wall as plugs, without being pre- 

 viouslv charred t were alone affected with 

 this disease. 



DKYANDRIA, in botany, so named in 

 honour of Jonas Dvyander, a Swede, and 

 a most excellent botanist, a genus of the 

 Dioecia Monadelpliia class and order. 

 Natural order of Tricoccae. Euphor- 

 bia, Jussieu. Essential character: ca- 

 lyx two-leaved ; corolla five-petalled ; 

 or, calyx five-leaved, resembling a co- 

 rolla, surrounded by a two or three leav- 

 ed calycle ; stamina nine ; fruit three or 

 four grained. There is but one species, 

 viz. D. cordata. 



DRYAS, in botany, a genus of the 

 Icosandria Polygynia class and order. 

 Natural order of Senticosz. Rosace x, 

 Jussieu. Essectial character: calyx five 

 to ten cleft; petals five to eight; seeds 

 tailed, hairy. There are two species, viz. 

 D. anemonoides, and D. octopetala. The 

 latter is a delicate evergreen plant, with 

 snow-white blossoms. The stalks and 

 branches are woody, and perennial, lying 

 flat upon the ground, spreading wide 

 about the roots in tufts. It is a native of 

 high mountains in Lapland, Denmark, 

 and Switzerland; also in Scotland and in 

 some parts of Yorkshire. It flowers in 

 June. 



DRYPIS, in botany, a genus of the 

 Pentandria Trigynia class and order. 

 Natural order of Caryophyllei. Essen- 

 tisl character : calyx five -toothed ; petals 

 five ; capsules clipped round, one seed- 

 ed. There is only one species, rir. D. 

 spinosa, the leaves of which are subulate, 

 somewhat three cornered, mucronate ; 

 those at the subdivisions of the stem are 

 lanceolate, with three teeth on each 

 side; peduncles shorter than the flower; 

 calyx erect ; corolla crowned, as in Si- 

 lene, purple or white ; petals very nar- 

 row, spreading; stamens erect. It is 

 biennial : native of Barbary, Italy, and 

 Istria. 



DUCATOON, a silver coin, frequent 

 in several parts of Europe. See Coix. 

 TABLE. 



DUCES tecum, in law, a writ that com- 

 mands a person to appear in the Court of 

 Chancery, and bring with him certain 

 writings, evidences, or other things, 

 which the court is inclined to view. \ 



DUCK. See AWAS. X^, 



DUCKING at the main-yard, among 

 sea-men, is a way of punishing offenders 

 on board a ship ; and is performed by 

 binding the malefactor, by a rope, to the 

 end of the yard, from whence he is vio- 

 lently let down into the sea, once, twice, 

 or three times, according to his offence : 

 and if the offence be very great, he is 

 drawn underneath the keel of the ship, 

 which they call keel-haleing. 



DUCT, in general, denotes any tube 

 or canal. See ANATOMT. 



DUCTILITY, in physics, a property of 

 certain bodies, whereby they are capa- 

 ble of being expanded, or stretched 

 forth, by means of a hammer, press, &c. 



The great ductility of some bodies, 

 especially gold, is very surprising : the 

 gold-beaters and wire-drawers furnish 

 us vi'h abundant proofs of this proper- 

 ty ; they, every day, reduce gold into 

 lamellae inconceivably thin, yet without 

 the least aperture, or pore, discoverable, 

 even by the microscope : a single grain 

 of gold* may be stretched under the ham- 

 mer into a leaf that will cover many 

 square inches, and yet the leaf remain 

 so compact as not to transmit the rays of 

 light, nor even admit spirit of wine to 

 transude. Dr. Halley took the following 

 method to compute the ductility of gold : 

 he learned from the wire-drawers that 

 an ounce of gold is sufficient to gild, 

 that is, to cover or coat a silver cylinder 

 of forty-eight ounces weight, which cy- 

 linder mav be drawn out into a wire so 



