diophthalmus 
diophthalmus (di-of-thal'mus), n. [NL., < Gr. 
Si- two-, + bjOoA/ids, eye.] Same as binucii- 
-*,3. 
1628 
And now that it has been shown that these images arc 
not formed dioptrically, but are the result of numerous 
"diffraction-spectra," it is impossible to entertain the 
same confidence as before. IF. B. Carpenter, Micros., f 277. 
(di-op'triks), n. [PI. of dioptric (see 
after Gr. TO dioirTpmd, the science of di- 
,..-. , , - - , -f uuuocs.] That part of optics which treats of 
by animals for defense or attack), + tirtpiov, <, the re f rac t} on o f light passing through differ- 
ttnp, a wild beast.] A genus of fossil siremans ent media as air wa ter, or glass, and especial- 
from South Carolina, characterized by the pre j through lenses. The term is now not much used 
Diospyros 
gions of America and Asia. They have fleshy tuberous 
roots, containing a large amount of starch, and several 
species are extensively cultivated for food in many tropi- 
ence of two incisors, whence the name. 
diopside (di-op'sid or -sid), n, 
view through (< Sid, through, H . 
-wfe 2 .] A variety or subspecies of pyroxene, 
containing as bases chiefly calcium and mag- 
nesium, with more or less iron. It occurs in pris- 
by scientific writers, the phenomena to which it refers 
[< Gr. Sunlc_, a being treated under the general head of refraction (which 
' ' a view) + see). See also lens, light, and optics. Also called anaclas- 
or a greenish- or yellowish-white color. Fine specimens 
f __ A dioptric. 
(di-6-ra'ma), n. [< Gr. as if 'Siopa/ta, 
come from the Mussa Alp, in the Ala valley in Piedmont. < diopdv, see' through, < 6td, through, + bpdv, 
Also called alalite and Mugsite see a. panorama.} 1. A spectacular paint- 
DiopsiS (di-op sis), n. [NL., < Gr. &-, two-, + j or j connected series of paintings, in- 
- ''if, view. Cf. dwpstde.} 1. In entom., a ge- te ded for exhibition to spectators in a dark- 
nus of dipterous in- 
sects, of the family 
Muscidai, or flies, it 
is characterized by the 
immense prolongation of 
the sides of the head, 
which thus appears as if 
it were furnished with 
long horns knobbed at 
the end. All the known 
species are from tropical 
regions of the old world. 
2. A genus of tur- 
bellarian worms. 
A species of Du 
diprism (di'o-rizm), n. [< Gr. fiiopia/idf, divi- 
diontra < Gr s in, distinction, < diopifrtv, divide, distinguish, 
onsisting of a draw a Boundary through,_ < iia, through, + op- 
ened room, in a manner to produce by optical 
illusions an appearance of reality. The paintings 
are so executed and arranged that a variety of effects may 
be induced by varying the direction, intensity, and color of 
the light ; one of the most notable of these effects coming 
from light transmitted through the picture itself, which 
is painted in transparent coloring on a thin fabric. Dif- 
ferent scenes may be painted on the two faces of the fab- 
ric, and a change from one to the other may be made by 
altering the source of the illumination. A daylight scene 
may be thus changed with wonderful realism to one by 
moonlight, or a desert place may become all at once peo- 
pled by a busy crowd. The diorama was devised in 1822 
by Daguerre (the chief inventor of photography) and Bou- 
ton. 
r. did, through, + ovraaia, 2. A building in which dioramic paintings are 
later form of tyif, view ; cf. birTdC,eo6a.i, be seen.] j. (( jj - r m 'fc\ a r< 
lucent mineral, occurring crystal 11 '""' 1 '" '~- P ert ainm! 
sided prisms. 
diopter (di-op't6r), n. [Also, as L. 
P^^^^ 1 ?^^^!^ f-,. a7 a boundary^ W, fi a boundary: see 
and provided with sights at the two ends and 1'onzon.} 1. Distinction; definition. [Rare.] 
a water-level, < fid, through, + OTTT-, ]/ *bv, in To eat things sacrificed to idols is one modi 
bijieaffai, see, birrtKOf, optic, etc. : see optic.} 1. C ^J ^^^tfore^Epis'tU'Tto'tlfe^Seveii Ch 
dade a or 1 indexarmof a^aduated circle 6 3~ 2 - ^ m.atn., a statement of the conditions un- 
An instrument used in craniometry for obtain- der which the problem to which it belongs is 
ing projections of the skull. 4. A dioptric. * olu . b i?' ,. . .. , , ,- - . , t ., - , 1N 
dioptra n. Plural of dioptro*. ^oristic, dionstical (di-o-ns'tik, -ti-kal) . 
dioptrate (di-op'trat), a. [< Gr. Sid, through, [< Gr. iiopurriKof, distinctive, < tiop^iv, distm- 
T b, V *67r in b^ai, see (see diopter)? + S<mh: see *0n.] Distinguishing; denning. 
-ate 1 .} In entom., divided by a transverse par- *""!". L, are /J- - . ,.. , , .s 
tition, as the compound eves of certain aauatie dioristically .(d>9-ris ti-kal-i)^ 
beetle 
centre 
mark. , Nicolaitism dioristically, as idolatry in general before by 
dioptric (di-op tnk), n. and n. [< Gr. OttMrrpUflJf, ea ti n g things sacrificed to idols, 
pertaining to the use of the diopter, < SiAirrpa, Dr. a. More, Epistles to the Seven Churches, p. 72. 
diopter: see diopter.} I. a. 1. Affording a me- di or it e (di'o-rit), n. [So called because formed 
dium for the sight ; assisting vision in the view o f distinct portions ; irreg. < Gr. Siop^uv), sep- 
of distant objects. arate, distinguish (see diorism), + -ite 2 .} The 
View the asperities of the moon through a dwptrick name given by Haiiy to a rock included among 
glass, and venture at the proportion of her hills by their those varieties which had before that time 
shadows. Dr. H. More, Antidote against Atheism, ii. 12. been generally designated by the name green- 
2. Pertaining to dioptrics, or the science of re- s tone. Diorite consists essentially of a crystalline-granu- 
fracted light. 
lar aggregate of a triclinic feldspar and hornblende, in 
- 
Dioptric system, in lighthouses, a mode of lighting in 
which the illumination is produced by a central lamp, the 
rays from which are trans- 
mitted through a combi- 
nation of lenses surround- 
probability, altered basalts ; some, however, may have re- 
sulted from the alteration of andesites, and even of gab- 
liros. In the case of diorite, the alteration has proceeded 
further than it has in the diabases and melaphyres. See 
greenstone and diabase. 
ing it. Also called the re- dioritic (di-6-rit'ik), a. [< diorite + -ic.'] Per- 
j ,,jstem. 
actuig y*tem. taining to or of the nature of diorite. 
tractive tower of a <"rthosis (di-or-tho'sis), n. [NL., < Gr. . 
r f Oueis, a making straight, as the setting of a 
ens (or inverse focal ^ amendm | nt con . e c'tion, < Ao^fmake 
divitl' bT a mTer! f"^*. < *'"> %&> + W*> ? ake st / ai f. ht ' 
Th?,mmeri<il measure of <,/^f- straight] 1. In surg., .the reduction 
the power of a lens ex- of a fracture or dislocation, or the restoration 
pressed in dioptrics is the of crooked or distorted limbs to their proper 
section of Fresnei's Dioptric Light, ratio of one meter^tojthe shape. 2. A recension or critical edition of a 
the latter being measured positively in the direction away -V t fIK.? rO / I K' - 
from the source of parallel rays entering the lens; so that a diorthotic (fii-or-thot lk), a. [< Gr. atopttoriKOf, 
convex lens with a focal length of hah* a meter would have corrective. < 6iop6aaif, correction : see diortho- 
apowerof 2 dioptrics, and a concave lens with a focal length e ; n i 'Rnlatino'tA flip pmpTirlnrinTt nr pnm*Ap- 
of^O Ujme^ would have a ,x,wer of -4 dioptrics' ^ Ji1Zto^ 
No sooner had Scaliger placed himself by common con- 
sent at the head of textual criticism, than he took leave 
for ever of diorthotic criticism. Quarterly Her. 
2. In surg., relating to diorthpsis. 
honor of 
dioptrical (di-op'tri-kal), a. Same as dioptric. an ist.] A 'large genus of "twining "plants, the 
dioptrically (di-op'tri-kal-i), adv. By refrac- type of the natural order Dioscoreaeea. There 
tion. are about 150 species, belonging chiefly to the warmer re- 
f 250 millimeters would have a power of 4 dioptrics. 
Owing principally to differences in the length of the 
inch in various countries, this method [the inch being used 
as the unit] had great inconveniences, and is now giving 
place to a universal system, in which the unit is the re- 
fractive power of a lens whose focal length is one metre. 
. ., . 
This unit is called a dioptric (usually written "^ DiOSCOrea (di-os-ko're-a), n. [NL., ill hon 
Dioseorides, a famous Greek physician and 
- - 
Chinese or Japanese Yam (Dioscorea Batatas}. 
i. Female flowers and fruit, a. Male flowers. ( From Le Maout and 
Decaisne's " Traite general de Botanique.") 
cal and subtropical regions. The principal species thus 
cultivated, commonly known as yams, are D. satim, D. 
aculeata, D. alata, and the Chinese or Japanese yam, D. 
Batatas. See yaw. 
Dioscoreaceae (di-os-ko-re-a'se-e), n. pi. [NL., 
< Dioscorea + -acete.} A natural order of en- 
dogenous plants distinguished by their ribbed, 
reticulately veined leaves, tuberous roots or 
knotted rootstocks, twining stems, and incon- 
spicuous difficious flowers. It includes 8 genera and 
about 1BO species, and is represented in the United States 
by a single secies, Dioscorea, villosa. 
dioscoreacCOUS (di-os-ko-re-a'shius), a. Be- 
longing to or having the characters of the Dios- 
coreaceai. 
dioscorein (di-os-ko're-in), n. [< Dioscorea + 
-iw2.] A precipitate formed by adding water 
to the tincture of the roots of Dioscorea villosa, 
used medicinally by eclectic physicians. 
Dioscuri (di-os-ku'ri), n. pi. [< Gr. hioaKovpoi, 
later and Ionic form of Atoanopoi, pi. (rarely in 
sing. Aioraopof), < A(0f, gen. of Zri'f, Zeus, + 
K<ipof, Ionic Koiyxjf, a son, a boy, lad.] In Gr. 
mytJi., the twin sons of Zeus and Leda, Castor 
and Polydeuces or Pollux, warrior gods, and 
tutelary protectors of sailors. At a compara- 
tively late date the Dioscuri were partly con- 
fused with the Cabin. 
To the Dioscuri, who always retained very much of their 
divine nature, belongs a perfectly unblemished youthful 
beauty, an equally slender and powerful shape, and, as an 
almost never-failing attribute, the half-oval form of the 
hat, or at least hair lying close at the back of the head, 
but projecting in thick curls around the forehead and tem- 
ples. C. 0. MMler, Manual of Archeeol. (trans.), 414. 
Dioscurian (di-os-ku'ri-an), a. [< Dioscuri + 
-an.} Pertaining to the'Dioscuri. 
Diosma (di-os'ma), 'ii. [NL., < Gr. diof, divine, 
+ bfsjiii, odor.] A genus of heath-like ruta- 
ceous plants, of about a dozen species, natives 
of South Africa. The foliage is resinous-dotted, and 
they all diffuse a strong and generally disagreeable odor. 
Several species are occasionally cultivated in greenhouses 
for their white or pinkish flowers. 
diosmose (di-os'mos), n. [< NL. diosmosis, 
q. v.] Same as diosmosis. 
diosmosis (di-os-mo'sis), n. [NL., < Gr. Sid, 
through, + aa/i6f, a thrusting, pushing, < udelv, 
push: see osmose.'} In physics, the transuda- 
tion of a fluid through a 
membrane ; transfusion 
through imperceptible 
openings. The way in which 
the maternal and fetal circula- 
tions mingle in the placenta is 
;in example of diomotU. See 
osmoxig, exosmoxtis, endos-tnosix. 
diosmotic (di-os-mot'ik), 
o. [< diosmosis (-mot-) 
+ -ic.} Pertaining to di- 
osmosis; osmotic. 
Diospyros (di-os'pi-ros), 
. [NL., < L. diospyros 
(Plinv), < Gr. (!<rjrt>pof, a 
certain plant, i.e., A;of irv- 
p6f, lit. Zeus's wheat: Aiof, 
gen. of Zeuf, Zeus (see 
'/c us, deity); irvpor, wheat.] 
A large genns of trees and 
uiivillia nf tllA Tiatlivnl Flower and Fruit of Persimmon 
SlirUQS, C U16 ndlUldl Diosfj/ras yirfiaiaaa}. 
order Ebenaceie, natives 
of the warmer regions of the world, but belong- 
ing for the most part to Asia and Mauritius. 
