EXO 
&c. to have no existence in matter, or 
without the mind, the same thing may be 
proved of all sensible qualities whatever : 
thus, they say, heat and cold are only the 
affections of the mind, not at all patterns of 
real beings existing in corporeal substances, 
for that the same body which seems cold to 
one hand seems warm to another. Now, 
why may we not as well argue that figure 
and extension are not patterns or resem- 
blances of qualities existing in matter, be- 
cause, to the same eye, at different sta- 
tions, or to eyes of different structure, 
at the same station, they appear various ? 
Again, sweetness, it is proved, does not 
exist in the thing sapid, because the thing 
remaining unaltered, the sweetness is chang- 
ed to bitterness, as in a fever, or by any 
otherwise vitiated palate. Is it not as rea- 
sonable to say that motion does not exist 
out of the mind, since if the succession of 
ideas in the mind become sinister, the mo- 
tion, it is acknowledged, will appear slower, 
without any external alteration ? Again, 
were it possible for solid figured bodies to 
exist out. of the mind, yet it were impossi- 
ble for us ever to know it : our sehses, in- 
deed, give us sensations of ideas, but do not 
tell us that any thing exists without the 
mind, or unperceived, like those which are 
perceived ; this the materialists allow. No 
other way therefore remains, but that we 
know them by reason’s inferring their ex- 
istence from what is immediately perceived 
by sense ; but how should reason do this, 
when it is confessed there is not any neces- 
sary connection between our sensations and 
these bodies? It is evident, from the phae- 
nomena of dreams, phrensies, &c. that we 
may be affected with the ideas we now 
have, though there were no bodies existing 
without them ; nor does the supposition of 
external bodies at all forward us in con- 
ceiving how our ideas should come to be 
produced.” 
EXOACANTHA, in botany, a genus of 
the Pentandria Digynia class and order. 
Natural order of Umbellatae. Essential 
character : involute spiny ; involucle halv- 
ed, with unequal rays; flowers all herma- 
phrodite, with equal, inflex, heart-shaped 
petals ; seeds ovate, striate. There is but 
one species, viz. E. heterophylla, found by 
Billardiere near Nazareth. 
EXOCCETUS, the flying fish, in natural 
history, a genus of fishes of the order Ab- 
dominales. Generic character : head scaly ; 
mouth without teeth ; jaws connected on 
each side ; gill membrane, ten-rayed ; pec- 
VOL. III. 
EXO 
toral fins very long and large, and giving, 
to a certain degree, the power of flight. 
There are three species. We shall particu- 
larly notice the E. exilien, or the Mediter- 
ranean flying-fish. This is about fourteen 
inches in length, and is found principally in 
the Mediterranean and Atlantic Seas, fre- 
quently alone, and sometimes in small com- 
panies. By the extraordinary length of its 
pectoral fins it is enabled to quit the water 
and support a flight, about three feet above 
the surface, for the distance of eighty or 
a hundred yards, after which it is obliged 
to return to the water and moisten its fins, 
which, even in this short progress, become 
hard and dry. These fishes are persecuted 
by the dorado under the water, and by the 
gull, or albatross, above the surface of it, ' 
and thus often escape destruction by the 
one only to incur it from the other. This 
faculty of maintaining short flights in the 
air is possessed by several other fishes, par- 
ticularly by the scorpaena and the trigla. 
The air-bladder of the flying -fish is ex- 
tremely large, and, of consequence, highly 
assisting to its aerial progress. The roe of 
this fish is reported to be highly caustic ; 
the smallest quantity applied to the tongue 
producing some degree of excoriation. For 
a representation of the oceanic flying-fish, 
see Pisces, Plate IV, fig. 2. 
EXORDIUM, in rhetoric, is the pream- 
ble or beginning, serving to prepare the au- 
dience for the rest of the discourse. Exor- 
diums are of two kinds, either just and for- 
mal, or vehement and abrupt. The last are 
most suitable on occasions of extraordinary 
joy, indignation, or the like. All exordiums 
should be composed with a view to capti- 
vate the good will, or attract the attention 
of the audience. The first may be done by 
paying them some compliment: thus St. 
Paul, “ I think myself happy, king Agrippa, 
because I shall answer for myself this day 
before thee, touching all the tilings whereof 
I am accused with the Jews, especially 
because I know thee to be expert in ail 
customs and questions which are among the 
Jews.” 
The requisites in an exordium are, 1. 
Propriety, whereby it becomes of a piece 
with the subject, and matches it as a part 
does a whole : in this the Greeks were very 
defective. 2. Modesty, which very much 
recommends the orator to the favour of his 
audience. And, 3. Brevity, not amplified 
or swelled with a detail of circumstances. 
EXOTERIC, and Esoteric, terms de- 
noting external and internal, and applied 
