Dryolestes 
Jurassic ago, remains of which are found in the 
AtJantosaurns beds of the Rocky Mountain re- 
gion of North America, indicating an animal 
related to the opossum. 
Dryolestidse (dri-o-les'ti-de), n. pi. [NL., < 
Dryolestes + -idai."] A family of extinct mar- 
supial mammals, represented by the genus Dry- 
olestes. 
Dryophidae (dri-of'i-de), n. pi. [NL., < Dry- 
aphis + -idte.] A family of aglyphodont or 
colubriform serpents; the whip-snakes. They 
have an extremely slender form and a greenish color ; 
their habits are arboreal, and they inhabit warm countries. 
The pupil is horizontal, and the dentition characteristic ; 
the snout is sometimes prolonged into a flexible appen- 
dage. There are several genera. 
DryopMs (dri'o-fis), n. [NL., < Gr. Spiif, a tree, 
esp. the oak, -f- 6<j>if, snake.] A genus of colu- 
briform serpents, typical of the family Dryophi- 
dce, or whip-snakes, having no nasal appendage 
and keeled scales. D. acuminata and D. ar- 
gentea are two South American species. 
Dryopithecus (dri"o-pi-the'kus), n. [NL., < 
Gr. ifpiif, a tree, esp. the oak, = E. tree, + iriQr/- 
KOf, an ape.] A genus of extinct anthropoid 
apes from the Miocene of France, of large size 
and among the highest simians, regarded by 
Gervais and Lartet as most closely related to 
the early ancestors of man. These apes were 
of nearly human stature, and were probably 
arboreal and frugivorous. 
Dryoscopus (dii-os'ko-pus). n. [NL. (Boie, 
1826), < Gr. 6pvf, a tree, esp. the oak, + OKonelv, 
view.] An extensive genus of shrikes, of the 
family Laniidee, containing about 22 species, 
all confined to Africa. The type is D. cubla. The 
bill is always hooked and notched, but varies in propor- 
tion of height to width in different species. The nostrils 
are oval and exposed, the wings and tail rounded and of 
about equal lengths, and the tarsi scutellate. The plu- 
mage of the back and rump is extremely fluffy ; the colora- 
tion is black and white, sometimes with an ochraceous 
tinge but without any bright colors, and is alike in both 
sexes. Also called Hapalonotus, Chaunonotus, and Rhyn- 
chastatus. 
dry-point (dri' point), n. and a. I. n. 1. A 
steel instrument or etching-needle with a sharp 
point, used by etchers to cut delicate lines on 
copperplates from which the etching-ground 
has been removed. The bur raised by the cutting of 
the metal ia either left standing on one side of the furrow 
to catch the printing-ink and produce a mezzotint effect 
of more or less deep tone, or removed with the burnisher 
so that the line may yield a clean impression. 
2. The process of engraving with the dry-point. 
II. a. In engraving, an epithet applied to a 
line made with the dry-point, or to an engrav- 
ing produced by means of that instrument. 
dry-pointing (dri'pom'ting), n. The grinding 
of needles and table-forks. 
Drypta (drip'ta), n. [NL. (Fabricius, 1801), ir- 
reg. < Gr. Apvirreiv (?), tear, strip.] A genus of 
adephagous beetles, of the family Carabidai. 
They are of small size and slender, graceful form. There 
are 20 to 30 species, confined to the old world, especially 
well represented in the East Indies and Africa ; only 2 are 
European. D. marginata of Europe is the type. 
Dryptidaet (drip'ti-de), n. pi. [NL. (Laporte, 
1834), < Drypta + -idee.] A family of Coleoptera, 
named from the genus Drypta, now merged in 
Carabidai. 
dry-rent (dri'rent), n. In law, a rent reserved 
without clause of distress. 
dryrihedt, A false spelling of drearihead. 
dry-rot (dri 'rot), . 1. A decay affecting 
timber, occasioned by various species of fun- 
gi, the mycelium of 
which penetrates the 
timber, destroying 
it. Polyporus hybridus 
causes the dry-rot of oak- 
built ships ; Mendius la- 
crymans is the most com- 
mon and most formida- 
ble dry-rot fungus, found 
chiefly in fir- and pine- 
wood. Polyporus destruc- 
tor is common in Ger- 
many. Damp, uuventilated situations are most favorable 
to the development of dry-rot fungi. Dry wood is not 
attacked. Various methods have been proposed for the 
prevention of dry-rot ; that most in favor is to thoroughly 
saturate the wood with creosote, which makes it unfit for 
vegetation. (See Ityaniring.) Animal dry-rot is also found 
to be occasioned by the attack of fungi. 
2. Figuratively, a concealed or unsuspected in- 
ward decay or degeneration, as of public mor- 
als or public spirit. 
dry-rub (dri' rub), y. t. To make clean by rub- 
bing without wetting. 
dry-salt (dri'salt), v. t. To cure (fish, meat, 
hides, etc.) by salting and drying; dry-cure. 
drysalter (dri'sal'ter), n. ['< dry-salt, v., + 
-er 1 .] If. A dealer in salted or dried meats, 
pickles, sauces, etc. 
Dry-rot Fungus (Merultus lacry- 
mans). 
1786 
I became a merchant a wholesale trafficker ... In 
everything, from barrels of gunpowder down to a pickled 
herring. In the civic acceptation of the word, I am a 
merchant ; amongst the vulgar, I am called a drysalter. 
T. Hook, Gilbert Gurney, III. ii. 
2. A dealer in dyestuffs, chemical products, 
etc. [Great Britain.] 
drysaltery (dri'sal'ter-i), . [< dry-salt + -try.~\ 
1. The business of a drysalter. 2. The articles 
kept by a drysalter. 
dry-shod (dri'shod), a. Having dry shoes or 
feet. 
Dry-shod to passe she parts the flouds in tway. 
Spenser, F. Q., I. x. 20. 
Those Feet, that dry-shod past the Crimsin Gulf, 
Now dance (alas !) before a Molten Calf. 
Sylvester, tr. of Du Bartas's Weeks, ii., The La we. 
dry-stone (dri'ston), a. Composed of stones 
not cemented with mortar : as, dry stone walls, " 
Scott. 
dry-stpve (dri'stov), n. A glazed structure for 
containing plants which are natives of dry cli- 
mates. 
drytht, n. [< dry + -th; a mod. formation, as 
a var. of drouth, with direct ref. to dry. See 
drought^, drouth.'] Same as drought^. 
dry-vatt (dri'vat), . A basket, box, or pack- 
ing-case for containing articles of a dry kind. 
Also dry-fat. 
I am a broken vessel, all runs out : 
A shrunk old dryfat. 
B. Jonson, Staple of News, iii. 2. 
Charles has given o'er the world ; I'll undertake 
... to buy his birthright of him 
For a dry-fat of new books. 
Fletcher (and another), Elder Brother, L 2. 
D. S. An abbreviation of dal segno. 
d/S. An abbreviation of days' sigh t, common in 
commercial writings : as, a bill payable at 10 
d/s. (that is, ten days after sight). 
D. Sc. An abbreviation of Doctor of Science. 
dso, n. [E. Ind.] A valuable hybrid between 
the yak and the common cow. Encyc. Brit., 
XIV. 197. 
D-string (de'string), n. The third string on 
the violin, and the second on most other in- 
struments played with a bow; the third string 
on the guitar. 
duad (du'ad), n. [Var. of dyad, after L. duo, 
two: see dyad, dual."] 1. Same as dyad. 2. In 
math., an unordered pair; two objects consid- 
ered as making up one, and as the same one 
whichever is taken first. 
duadic (du-ad'ik), a. 1. Same as dyadic. 2. 
In math., composed of unordered pairs. 
dual (du'al), a. and n. [< L. dualis, of two (in 
gram. tr. Gr. iviit6f), < duo = Gr. Svo = E. two, 
q. v.] I. a. 1. Eelating to two ; specifically, 
in gram., expressing two, as distinguished from 
singular, expressing one, and from plural, ex- 
pressing more than two. The languages of our fam- 
ily originally had a dual number, both in declension and in 
conjugation ; it is preserved in Sanskrit and Greek, and 
less fully in other tongues, as Gothic. Dual forms also 
occur in other families. 
2. Composed or consisting of two parts, quali- 
ties, or natures, which may be separately con- 
sidered ; twofold; binary; dualistic: as, the 
dual nature of man, spiritual and corporeal. 
Faint glimpses of the dual life of old, 
Inward, grand with awe and reverence ; outward, mean 
and coarse and cold. Whittier, Garrison of Cape Ann. 
II. n. In gram., the number relating to two; 
the dual number. 
The employment of a dual for the pronouns of the first 
and second persons marks an early date. 
Genesis and Exodus (E. E. T. 8.), Pref., p. xiv. 
dualin (dii'a-lin), n. [< dual, of two, + -in 2 .] 
A mixture "of 30 parts of fine sawdust, 20 of 
saltpeter, and 50 of nitroglycerin, used as an 
explosive. Also called dualin-dynamite. 
dualism (du'a-lizm), n. [= F. dualisme = Sp. 
Pg. It. dualismo = D. G. dualismus =Dan. dua- 
lisme = Sw. dualism ; as dual + -ism.] 1 . Divi- 
sion into two ; a twofold division ; duality. 
An inevitable dualism bisects nature, so that each thing 
is a half, and suggests another thing to make it whole : as, 
spirit, matter; man, woman ; odd, even; subjective, ob- 
jective ; in, out ; upper, under ; motion, rest ; yea, nay. . . . 
The same dualism underlies the nature and condition of 
man. Emerson, Compensation. 
2. In philos., in genera], that way of thinking 
which seeks to explain all sorts of phenomena 
by the assumption of two radically independent 
and absolute elements, without any continuous 
gradation between them: opposed to monism. 
In particular, the term is applied (rt) To the doctrine 
that spirit and matter exist as distinct substances, thus 
being opposed both to idealism and to materialism. 
Berkeley then is right in triumphing over Realism and 
Dualism. Right in saying that if he were to accord them 
dub 
the existence of matter they coultl make no use of it. The 
subject would remain as dark as before. Q. H. Leues. 
(b) To the doctrine of a double absolute, especially a prin- 
ciple of good and a principle of evil, or a male and a fe- 
male principle. 
Rudimentary forms of Dualism , the antagonism of a Good 
and Evil Deity, are well known among the lower races of 
mankind. E. B. Tylor, Prim. Culture, II. 287. 
3. In theol. : (a) The doctrine that there are two 
independent divine beings or eternal principles, 
one good and the other evil : characteristic es- 
pecially of Parsism and various Gnostic sys- 
tems, (b) The heretical doctrine, attributed 
to Nestorius by his opponents, of the twofold 
personality of Christ, the divine logos dwelling 
as a separate and distinct person in the man 
Christ Jesus, and the union of the two natures 
being somewhat analogous to the indwelling 
of the Holy Spirit in the believer; that view of 
the personality of Christ which regards him as 
consisting of two personalities. 4. In chem., 
a theory advanced by Berzelius which assumed 
that every compound, whether simple or com- 
plex, must be constituted of two parts of which 
one is positively and the other negatively elec- 
trified. Thus, for example, sodium sulphate is put toge- 
ther not from sulphur, oxygen, and sodium, but from sul- 
phuric acid and soda, which can themselves be separated 
into positive and. negative constituents. Muir, Principles 
of Chemistry. 
5. In general, any system or theory involving 
a duality of principles Creatural dualism. See 
ereatural. Hypothetic dualism. Sec hypothetic. Nat- 
ural dualism, the doctrine of a real subject and a real 
object in cognition accepted unreflectively. Persian, 
dualism, the doctrine of a good and an evil active princi- 
ple struggling against each other in the government of 
human affairs and destiny. Realistic dualism, the 
doctrine that the universe consists of two kinds of reali- 
ties, spirit and matter. 
dualist (du'a-list), n. [= F. dualiste = Sp. Pg. 
It. dualista = D. Dan. Sw. dualist ; as dual + 
-ist.'] One who holds the doctrine of dualism 
in any of its forms; an opponent of monism; 
especially, one who admits the existence both 
of'spirit and of matter. Craig. 
dualistic (du-a-lis'tik), a. [= F. dualistiquc (cf. 
D. G. dualistisch = Dan. Sw. dualistislc) ; as du- 
alist + -ic. ] 1 . Consisting of two ; characterized 
by duality. 2. Of or pertaining to dualism; 
not monistic. 
The dualistic doctrine of a separate mind is therefore 
based upon an artificial and impassible separation of the 
two necessarily co-existent sides of thought-life, namely, 
the plastic and the functional. 
Maudsley, Body and Will, p. 118. 
In the Mazdean orZoroastrian religion we have the best 
example of a dualistic faith. Faiths of the World, p. 360. 
duality (du-al'i-ti), ! [< ME. dualitie = F. du- 
aliti= Pr. dualitat = Sp. dualidad = Pg. duali- 
dade = It. dualita, < L. as if *dualita(t-)s, < du- 
alis, dual : see dual.] The state of being two, 
or of being divided into two ; twofold division 
or character; twoness. 
This dualitie after determission is founden in euery 
creature, be it neuer so single of onhed. 
Testament of Love, ii. 
Though indeed they be really divided, yet are they so 
united as they seem but one, and make rather a duality 
than two distinct souls. 
Sir T. Browne, Religio Medici, ii. 5. 
To the schoolmen the duality of the universe appeared 
under a different aspect 
Huxley, Nineteenth Century, XXI. 192. 
The principle of duality, in geom., the principle that 
in any proposition not involving measure, if for "point" 
be everywhere substituted "plane," and vice versa, the 
latter proposition will be as true as the former. 
Upon this supposition of a positive curvature, the whole 
of geometry is far more complete and interesting ; the 
principle of duality, instead of half breaking-down over 
metric relations, applies to all propositions without ex- 
ception. W. K. Clifford, Lectures, I. 323. 
duan (du'an), n. [< Gael, duan, a poem, canto, 
ode, song, ditty, oration, = Ir. duan, a poem, 
song. Cf. Ir. duar, a word, saying, duas, a 
poet.] A division of a poem; a canto; also, a 
poem or song. Sitrns; Byron. 
duarchy (du'ar-ki), ..: pi. dimrchies (-kiz). 
[Prop. *dyarchy, < Gr. TOO, = E. two, + -ap r \ia, 
* apxeiv, rule.] Government by two persons; 
diarchy (which see). 
Siam is practically a monarchy, although nominally a 
duarchy, the second king hardly holding the power of a 
vice-king. Harper's Weekly, XXVIII. 330. 
dub 1 (dub), v. t. ; pret. and pp. dubbed, ppr. 
dubbhig. [< ME. dubben, rarely dobbeti, doub- 
ben, dub (also in comp. adiibben : see adub), < 
late AS. *duoban (only once in pret. dubbade : 
" Se cyng [William the Conqueror] dubbadehis 
sunu Henric to ridere," the king dubbed his 
sou Henry a knight) (whence the equiv. Icel. 
dubba til riddara, Sw. <lubba till riddare; Icel. 
dnbhrt, also, equip with arms, dress), (. OF. 
