BAL 
BAL ' 
lasting, as it is called, consists in placing the 
centre of gravity, so as neither to be too 
high nor too low, too far forward nor too 
far aft, and that the surface of the water 
may nearly rise to the extreme breadth 
amidship, and thus the ship will be enabled 
to carry a good sail, incline but little, and 
ply well to the windward. 
BALLET, in music, a theatrical repre- 
sentation of some tale or fable told in 
dance, or metrical action, accompanied 
with music. The artist who invents and 
superintends the rehearsal and peformance 
of the ballet is called the ballet-master. 
BALLISTA, in antiquity, a military ma- 
chine used by the ancients in besieging 
cities, to throw large stones, darts, and 
javelins. 
It resembled our cross-bows, though 
much larger, and superior in force. 
From this engine stones of a size not less 
than mill-stones were thrown with so great 
violence, as to dash whole houses in pieces 
at a blow. It is described thus: a round 
iron cylinder was fastened between two 
planks, from which reached a hollow square 
beam, placed crosswise, and fastened with 
cords, to which were added screws ; at one 
end of this stood the engineer, who put a 
wopden shaft with a big head into the cavity 
of the beam : this done, two men bent the 
engine by drawing some wheels : when the 
top of the head was drawn to the utmost 
end of the cords, the shaft was driven out of 
the ballista, &c. 
BALLOON, or Ballon, in a general 
sense, signifies any spherical hollow body, 
of whatever matter it be composed, or for 
whatever purposes it be designed. 
Thus, with chemists, balloon denotes a 
round short-necked vessel, used to receive 
what is distilled by means of fire ; in archi- 
tecture, a round globe on the top of a pillar ; 
and among engineers, a kind of bomb made 
of pasteboard, and played off in fire-works, 
either in the air or in the water, in imitation 
of a real bomb. Balloon, in the French 
paper trade, is a term for a quantity of pa- 
per, containing 24 reams. It is also the 
name of a sort of brigantine used in the 
kingdom of Siam. 
Balloon. See Aerostation. 
BALLOTA, in botany, a genus of the 
Didynamia Gymnospermia class and order. 
Natural order of the Verticillatas, or La- 
biatse. Essential character: calyx salver- 
shaped, five-toothed, ten-streaked: corolla 
upper-lip crenate, concave. There are six 
species. B. nigra is the black or stinking 
horehound, a hairy plant, with an upright 
brownish stem, about two feet in height. 
It is a perennial plant, common in most 
parts of Europe, in waste places and hedges, 
flowering in July. It is recommended in 
hysterical cases. In Gothland it is an uni- 
versal remedy for cattle ; but the Swe- 
dish plant is probably not the same, as ours. 
The European sorts, being common stink- 
ing weeds, are never introduced into gar- 
dens. 
BALLS, or Ballets, in heraldry, a fre- 
quent bearing in coats of arms, usually deno- 
minated according to their colours, bezants, 
plates, hurts, & c. 
BALM, or Baum, in botany. See Me- 
lissa. 
BALNEUM, a term used by chemists to 
signify a vessel filled with some matter, as 
sand, water, or the like, in which another is 
placed that requires a more gentle heat than 
the naked fire. 
BALSAM, or Native Balsam, an oily, 
resinous, liquid substance, flowing either 
spontaneously, or by means of incision, 
from certain plants of sovereign virtue in 
the cure of several disorders. 
The term balsam, or balm, was originally 
confined to a thick fragrant juice, obtained 
from the amyris Gileadensis, and afterwards 
applied by chemists to all substances which 
possessed the same degree of consistence 
and a strong smell, whether natural or arti- 
ficial. The word balsam originally implied 
a substance possessing a certain degree of 
fluidity : but now there are two classes of 
balsams ■ the one fluid, and the other solid 
and brittle. A balsam, then, is a substance 
which possesses the general properties of a 
resin; but which, when heated or digest- 
ed in acids, yields a portion of benzoic 
acid. See Benzoin. 
Chemists, in general, have considered 
them as combinations of a resin with ben- 
zoic acid ; but Mr. Hatchett has made it 
probable, that the acid is formed at the 
time of its separation. They are insoluble 
in water ; but when boiled in that liquid 
often give out a portion of benzoic acid. 
Alcohol and ether dissolve them readily. 
The strong acids, likewise, dissolve them, 
and during the solution a portion of ben- 
zoic acid is separated. Nitric acid, in some 
cases, evolves likewise traces of prussic 
acid. The alkalies act upon them nearly 
as on the resins. They may be divided in- 
to two classes; namely, liquid and solid 
balsams. 
