EXA 
sorts resembling the upright cactuses ; arm- 
ed with prickles, which are either solitary 
or in pairs, placed in a single row on the top 
of the ridges. 
EUPHRASIA, in botany, English eye- 
bright, a genus of the Didynamia Angios- 
permia class and order. Natural order of 
Personatae. Pediculares, Jussieu. Essen- 
tial character : calyx four-elefr, cylindric ; 
capsule two-celled, ovate, oblong; lower 
anthers have a little thorn at the base of 
one of the lobes. There are nine species. 
EURYA, in botany, a genus of the Do- 
decandria Monogynia class and order. Es- 
sential character: calyx five-leaved, caly- 
cled ; corolla five-petalled ; stamina thirteen ; 
capsule five-celled. There is but one spe- 
cies, viz. E. japonica, a native of Japan. 
EURYANDRA, in botany, a genus of 
the Polyandria Trigynia class and order. 
Natural order of Coadunatas. Magnolias, 
Jussieu. Essential character: calyx five- 
leaved ; corolla three-petalled ; filament 
much dilated at the tip, with twin disjoined 
anthers ; follicles three. There is only one 
species, viz. E. scandens, a native of New 
Caledonia. 
EUSTACHIAN tube, in anatomy, begins 
from the interior extremity of the tympa- 
num, and runs forward and inwards in a 
bony canal, which terminates with a por- 
tion of the temporal bone. See Anatomy. 
EUSTEPHIA, in botany, a genus of the 
Hexandria Monogynia class and order. 
Corolla superior, tubular, cylindrical, bifid ; 
nectary six cavities in the tube of the co- 
rolla ; filaments tricuspidate, distinct. 
There is but a single species, viz. the coc- 
cinea. 
EUSTYLE, in architecture, a sort of 
building in which the pillars are placed at 
the most convenient distance one from ano- 
ther, the intercolumniations being just two 
diameters and a quarter of the column, ex- 
cept those in the middle of the face, before 
and behind, which are three diameters 
distant. 
EWRY, in the British customs, an office 
in the king’s household, which has the care 
of the table linen, of laying the cloth, and 
serving up water, in silver ewers, after 
dinner. 
EXAGGERATION, in rhetoric, a kind 
of hyperbole, whereby things are augmented 
or amplified, by saying more than the truth, 
either as to good or bad. There are two 
kinds of exaggeration, the one of things, 
the other of words. The first is produced, 
EXC 
1. By a multitude of definition. 2. By a 
multitude of adjuncts. 3. By a detail of 
causes and effects. -1. By an enumeration 
of consequences. 5. By comparisons. And, 
6 . By the contrast of epithets and rational 
inference. 
Exaggeration by words is effected, 1. 
By using metaphors. 2. By hyperboles. 
3. By synonymous terms. 4. By a collec- 
tion of splendid and magnificent expres- 
sions. 5. By periphrasis. 6. By repetition. 
And lastly, by confirmation with an oath ; 
as for example, “ Parietes, medius fidius, 
gratias tibi agere gestiunt.” 
EXACUM, in botany, a genus of the 
Tetrandria Monogynia class and order. 
Natural order of Rotacese. Gentianas, 
J ussieu. Essential character : calyx four- 
leaved; corolla salver-shaped, with an in- 
flated tube; capsule two-furrowed, two- 
celled, many-seeded, bursting at the top. 
There are ten species. 
EXANTHEMA, among physicians, de- 
notes any kind of efflorescence or eruption, 
as the measles, purple spots in tlxe plague, 
or malignant fevers, , &c. 
According to Dr. Cullen it is an order in 
the class pyrexia, and includes all conta- 
gious diseases, beginning with fever, and 
followed by an eruption on the skin. 
EXCELLENCY, a title anciently given 
to kings and emperors, but now to embas- 
sadors, and other persons, who are not qua- 
lified for that of highness, and yet are to be 
elevated above the other inferior dignities. 
In England and France the title is now pe- 
culiar to embassadors, but very common in 
Germany and Italy. Those it was first 
appropriated to, were the princes of the 
blood of the several royal houses ; but they 
quitted it for that of highness, upon several 
great lords assuming excellency. 
EXCENTRIC, in geometry, a term ap- 
plied to circles and spheres which have not 
the same centre, and consequently are not 
parallel ; in opposition to concentric, where 
they are parallel, having one common cen- 
tre. 
Excentric circle, in the Ptolemaic sys- 
tem, the very orbit of the planet itself, 
which it was supposed to describe about the 
earth. 
Excentric circle, in the new astro- 
nomy, a circle described from the centre of 
the orbit of the planet, with half the axis as 
a radius. 
Excentric place of a planet, is the very 
point of the orbit, where the circle of incli- 
