D U C 
DUE 
553 DUC 
he is not able to bring his prisoner without 
danger ot death, he being adeo languidus : 
upon which the court grants a habeas corpus, 
in nature ot a duces tecum licet languidus. 
DUCK. See Anas. 
DUCKING, plunging irt water, a diver- 
sion antiently practised among the Goths, by 
way ot exercise ; but among the Celt*, 
b ranks, and antient Germans, it was a sort 
ot punishment for persons of scandalous 
lives. They were shut up, naked to the 
shift, in an iron cage, fastened to the yard of 
a shaloop, and ducked several times. 
Ducking at the ?nain-i/ard, among sea- 
men, is a way ot punishing ottenders on board 
a ship; and is performed by binding the ma- 
lefactor, by a rope, to the end of the yard, 
whence lie is violently let down into the sea, 
once, twice, or three tunes, according to his 
otfence: and if the offence is very great, he 
Is drawn underneath the keel of the siiip, 
which they call keel-haleing. 
DUCK-L P, at sea, is a term used by the 
steersman, when the mainsail, foresail, or 
spritsail, hinders his seeing to steer by a land- 
mark : upon which he calls out, “ Duck-up 
the clew-lines of these sails,” that is, hale the 
sails out of the way. Also, when a shot is 
made by a chace-piece, if the clew of the 
spritsail hinders the sight, they call out, 
“ Duck-up,” & c. 
DUCT, ductus, in general, denotes any 
tube or canal. See Anatomy. 
D U L, 1 1 1 .1 1 \ , in physics, a property of 
certain bodies, whereby they are capable of 
being expanded, or stretched forth, by means 
of a hammer, press, &c. See Mechanics. 
1 he great ductility of some bodies, espe- 
cially gold, is very surprising: the gold- 
beaters and wiredrawcrs furnish us with abun- 
dant proofs of this property ; they every day 
reduce gold into lame! he inconceivably thin’, 
yet without the least aperture or pore dis- 
coverable, even by the microscope: a single 
grain of gold may be stretched under the 
hammer, into a leaf that will cover a house, 
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 'ducti- 
lity of gold: he learned from the wiredraw- 
ers, that an ounce of gold is sufficient to 
gild; that is, to cover or coat, a silver cylin- 
der of forty-eight ounces weight, which' cy- 
linder may be drawn out into a wire so very 
hue, that two yards shall weigh only one 
grain; and consequently ninety-eight yards 
of the same wire, only forty-nine grain's: so 
that a single grain of gold here gilds ninety- 
eight yards ; and, of course, the ten-thou- 
sandth part of a grain is here above one-third 
or an inch long. And since the third part of 
an inch is yet capable of being divided into 
ten lesser parts visible to the naked eye, it is 
evident that the hundred-thousandth part of a 
grain of gold may be seen without the assist- 
ance of a microscope. Proceeding in his 
calculation, he found, at length, that a cube of 
gold, whose side is the hundredth part of an 
inch, contains 2,433,000,000 visible parts; 
and yet, though the gold with which such 
wire is coated, is stretched to such a degree, 
go intimately do its parts cohere, that there 
is not any appearance of the colour of the 
silver underneath. 
Mr. Boyle, examining some leaf-gold, 
found that a grain and a quarter in weight took 
up art area of fifty square inches ; supposing 
therefore the leaf divided by parallel lines 
100th part of an inch apart, a grain of gold 
will be divided into five hundred thousand 
minute squares, all discernible by a good 
eye: for the same author shews, that an 
ounce ot gold drawn out in wire would reach 
155 miles and a half. 
But Mr. Reaumur has carried the ductility 
of gold to a still greater extent. What is called 
gold-wire, every body knows, is only a silver 
one gilt. r Phe cylinder of silver, covered 
with leaf-gold, they draw through the hole of 
an iron, and the gilding still keeps pace with 
the wire, stretch it to what length they can. 
Now Mr. Reaumur shews, that in the com- 
mon way of drawing gold-wire, a cylinder of 
silver twenty-two inches long, aiid fifteen 
lines in diameter, is stretched to 1,163,520 
feet, or is 634,692 lines longer than before, 
which amounts to about ninety-seven leagues. 
To wind this thread on silk for use, they first 
flatten it, in doing which it stretches at least 
one-seventh farther, so that the twenty-two 
inches are now 111 leagues; but in the 
flattening, instead of one-seventh, they could 
stretch it one-fourth, which would bring it to 
120 leagues. This appears a prodigious ex- 
tension, and yet it is nothing to what this 
gentleman has proved gold to be capable of. 
Ductility of glass. We all know that, 
when well penetrated with the heat of the 
lire, the workmen can figure and manage 
glass like soft wax; but what is most re- 
markable, it may be drawn, or spun out, into 
threads exceedingly long and fine. 
Our ordinary spinners do not form their 
threads of silk, llax, or the like, with half the 
ease and expedition as the glass-spinners do 
threads of this brittle matter. We have some 
of them used in plumes for children’s heads, 
and divers other works, much finer than any 
hair, and which bend and wave like hair with 
every wind. 
Nothing is more simple and easy than the 
method ot making them. There are two work- 
men employed; the first holds one end of a 
piece of glass over the flame of a lamp; 
and, when the heat has softened it, a second 
operator applies a glass hook to the metal 
thus in fusion; and, withdrawing the hook 
again, it brings with it a thread of glass, 
which still adheres to the mass; then, fitting 
his hook on the circumference of a wheel 
about two feet and a half in diameter, he 
turns the wheel as fast as he pleases; which, 
drawing out the thread, winds it on its rim; 
till, after a certain number of revolutions, it 
is covered withaskainof glass-thread. 
The mass in fusion over the lamp dimi- 
nishes insensibly : being wound out like a 
clue of silk upon the wheel ; and the parts, as 
they recede from the flame, cooling, be- 
come more coherent to those next to them, 
and this by degrees: the parts nearest the 
fire are always the least coherent, and, of 
consequence, must give way to the effort the 
rest make to draw them towards the wheel. 
The circumference of these threads is 
usually a flat oval, being three or four times 
as broad as thick: some of them seem 
scarcely bigger than the thread of a silk- 
worm, and are surprisingly flexible. If the 
two ends of such threads are knotted toge- 
ther, they may be drawn and bent, till the 
aperture, or space in the middle of the knot, 
T i 
does not exceed one-fourth of a line, \sr one- 
forty-eighth of an inch, in diameter. 
H ence M. Reaumur advances, that the I 
flexibility of glass increases in proportion to 
the fineness ot the threads ; and that, proba- 
bly, had we but the art of drawing threads as s 
fine as a spider's web, we might weave stubs 
and cloths of them for wear. Accordingly, 
he made some experiments this way; and 
found that he could make threads tine enough, t 
viz. as fine, in his judgment, as spider’s 
thread, but he could never make them long 
enough to do any thing with them. 
DUEL, a single combat, at a time and 
place appointed, in consequence of a dial- j 
lenge. This custom came originally from 
the northern nations, among whom it was i 
usual to decide all their controversies by 1 
arms. Both the accuser and accused gave j 
pledges to the judges on their respective be- , 
halt; and the custom prevailed so far amongst 
the Germans, Danes, and Franks, that none f 
were excused from it but women, sick people, 
cripples, and such as were under twenty-one 
years of age, or above sixty. Even ecclesi- i 
astics, priests, and monks, were obliged to 
find champions to fight in their stead. The j] 
punishment of the vanquished was either i 
death by hanging or beheading, or muti- 
lation ot members, according to the circum- i 
stances of the case. Duels were at first ad- I 
mitted not only on criminal occasions, but on 
some civil ones for the maintenance of rights ■ 
to estates : in latter times, however, before 
they were entirely abolished, thev were re- J 
strained to these’ four cases: l.’That the 
crime should he capital. 2. That it should ; 
be certain the crime was perpetrated. 3, ' 
The accused must, by common fame, be sup- j 
posed guilty. And, 4. The matter not capo- j 
ble of proof by witnesses. In England, . 
though the trial by duel is disused, the law 
on which it is founded is still in force. 
DUELLING, or single combat, between 
any of the king’s subjects, of their own \ 
heads, and for private malice or displeasure, 
is now prohibited by the laws of this realm ; 
for in a settled state governed by law, no 
man, for any injury whatever, ought to use i 
private revenge. 3 Inst. 157. 
And where one party kills the other, it j 
comes within the notion of murder, as being j 
committed by malice aforethought; where 
the parties meet with an intent to murder, 
thinking it their duty as gentlemen, and j 
claiming it as their right to wanton with their 
own lives, and the lives of others, without : 
any warrant for it either human or divine ; j 
and therefore the law has justly fixed on j 
them the crime and punishment of murder. ? 
4 Black. 199- 
And the law so far abhors all duelling in 
cold blood, that not only the principal, who 
actually kills the other, but also his seconds, 
are guilty of murder, whether they fought or 
not; and it is holden that the seconds of the ■ 
party slain are likewise guilty as accessaries, i 
12 Haw. 8. 
DUETT, a composition expressly written 
for two voices or instruments, withorwithouta 
bass and accompaniments. In good duetts, the 
execution is pretty equally distributed be- 
tween the two parts; and the melodies so 
connected, intermingled, and so dependant 
on each other, as to lose every effect when 
separated, but to be perfectly related and * 
concinnous when heard together. Yet, how- 
