Encyclopaedia Britannica; or, A dictionary of arts and sciences, compiled upon a new plan … > Volume 2, C-L

CUM { 753 ') C U M
Hat. The Britifli, Dutch, French, ®nd other na
tions, have forts and faftories on this coaft.
Guinea is aifo the name of a Bxitilh gold-coin, value
i 1. is. Sterling.
Guinea-pig, in zoology. See Mu a.
GUIPUSCOA, the nonh-ealt divifion of the province of
Bifcay, in Spain, fituated on the confines of Navarre
in France.
GUIRA, or Guara Guainumbi, in ornithology, the
Brafilian name of the green ifpida, with a creftedhead
and very long tail.
GUISE, a town of France, in the province of Picardy,
fituated on the river Oyfe: E. long 3'0 36/, and N.
5at 49° 55'-
GUITAR, Guitar,ra, a mufical inftrument of the
firing kind, with five double rows of firings, of which
thofe that are bafs are in the middle, unlefs it be for
the burden, an o&ave lower than the fourth.
This inflrument was firft ufed in Spain, and by the
Italians.
GULA, or Gola, in architedlure, a wavy member, the
contour of wh-ch refembles the letter S, which the
Greeks call cymatium, and our archite&s an ogee.
See Architecture.
GULES, in heraldry fignifies the colour red, which is
exprefled in engraving by perpendicular lines falling
from the top of the efchutcheon to the_bottom. See
Plate Cl. fig 6.
It is the firft of all colours in armory, and was for¬
merly prohibited to be worn by any perfon in his coat-
armour, unlefs he were a ,prince, or had a permiffion
from him. This colour is a fymbol of charity, valour,
and generofity, and reprefents blood colour, and true
fcarht
The Romans, according to Spelman, painted the bo¬
dies of their gods, and generals that triumphed, with
vermilion ; and under the confuls, their foldiers were
clad in red; hence called ruffati. And we are told,
that the Lacedemonians wore fcarlet to prevent fee¬
ing the blood iffue from their wounds. Thofe who
bear this colour are obliged to relieve fuch as are in
danger of being opprefled by injullice.
GULL See Larus.
GULPH, or Gulf, in geography, a part of the fea,
almoft furrounded by lands, the gulph of Mexico,
gulph of Venice, of Lyons, <&c.
GUM, in pharmacy, a concreted vegetable juice, which
tranfudes through the bark of certain trees, and hardens
upon the furface.
Gum Arabic. See Cwzw Arabic.
Gum Seneca, is a gum extremely refembling gum ara-
bic. It is brought to us from the country through
which the-river Senega runs, in loofe or fingie drops,
but thefe are much larger than thofe of the gum arabic
ufually are; fometimes it is of the bignefs of an egg,
and lomeumes much larger : the furfaqe is very rough,
or wrinkled, and appears much lefs bright than the in¬
ner fubftance, where the maffes are broken. It has no
fmell, and fcarce any tafte. We are not acquainted
with the tree which produce? it. The virtues of it
are the fame with the gum arabic ; but it is rarely ufed
Voi. II. No. 58. 2
in medicine, unlefs as mixed with the gnm Arabic*
the dyers and other artificers confume the great quan¬
tities of it that are annually imported here. The ne¬
groes difiblve it in milk, and in that ftate make it a
principal ingredient in many of their diftus ; and often
feed on it thus alone.
Gum Tragacanth. See Tragacahth.
Gum manna. See Manna.
Other fubftances known by the name of gums, are
as follow.
Gum aloes, a preparation of aloes, as fet down in the
London Difpenfatory.
It is made thus : Take of fuccotrine aloes, four
ounces ; of water, a quart: boil the aloes till it is diA
folved as much as may be ; and let all by for a night:
the refin will be precipitated to the bottom of the vef-
fel; the liquor poured olf and drained, being evapo¬
rated, will have the gum. The intention of this fepa-
ration of the refin, is to procure, in the gum, a medicine
lefs purgative, but more agreeable to the ftomach, than
the crude aloes.
Gum ammoniac. See Ammoniac.
Gumelemi. See Elem 1.
Gum guaiacum. See Guaiacum.
Gum lacca. See Lacca.
Gums, in anatomy. See Anatomy, p, 305.
GUN, afire arm, or weapon of offence, which forcibly
difcharges a ball, Ihot, or other offenfive matter, thro'
a cylindrical barrel, by means of gun powder. See
Gunpowder,
Gun is a general name, under which are included
divers or even moft fpecies of fire-arms. They may
be divided into great and fmaM.
Great guns, called alfo by the general name can-
ncrs, make what we alfo call ordinance, or artillery ;
under which come the feveral forts of cannons,
as cannon-royal, demi-cannon, &c. Culverins, de-
mi-culverins, fakers, minions, falcons, &c. See
Cannon.
Small guns include mufquets, mufquetoons, cara¬
bines, biunderbuffes, fowling pieces, &c. See Mus-
qy et, ebe.
Piftols and mortars are almoft the only fort of regu¬
lar w'eapons, charged with gun-powder, that are ex¬
cepted from the denomination of guns. See Pistol
and Mortar.
The advantage of large guns, or cannons, over thofe
of a (mailer bore, is generally acknowledged. Robins
obferves, that this advantages arifes from feveral cir-
cumftances-, particularly in diftant cannonading. The
diftanceto which larger bullets fly with the fame pro¬
portion of powder, exceeds the flight of the fmalkr
ones, almoft in proportion to their diameters ; fo that
a thirty two pound fliot, for inftance being famev/hat
more than fix inches in diameter, and a nine pound fiiot
but four inches; the thirty-two pound will fly near
half as far again as that of nine pound, if both pieces
are fo elevated as to range to, the fartheft diftance pof-
fible Another and more important advantage of heavy
bullets is, that with the fame velocity they break holes
in ail folid bodits, in a greater proportion than their
8 D weight.