A M B 
A M B 
66 
dark and opaque, and is employed in this 
state in the composition of some varnishes. 
In burning it emits very penetrating vapours, 
burns with a greyish ilame, and leaves a 
coaly residuum. 
When this substance is distilled, the em- 
pyreumatic oil produced is mostly thick, and 
of a blackish colour, and has a heavy, pene- 
trating odour. When it is repeatedly distilled 
it becomes more fluid and transparent, and 
can be rendered quite limpid ; in which state 
it is said to resemble the finer kinds of pe- 
trolea, particularly the naphtha. It is then 
termed rectified oil of amber. 
The origin of amber has been much dis- 
puted, whether it is originally a fossil, or is 
produced from vegetable matter. The only 
reason to imagine it is entirely a fossil body 
is, that it is found at some depth below the 
surface under certain strata. The greatest 
part that we have comes from the Baltic. A 
considerable quantity is found floating on the 
sea on these coasts, being washed out of the 
soil by the agitation of the waves, when they 
penetrate through different strata, first through 
one containing fossil wood, variously com- 
pacted together ; under this a stratum of vit- 
riolic minerals ; below this the amber is found 
dispersed in various sizes; but when it is ex- 
amined, we find manifest proofs of its having 
been produced originally at the surface of the 
earth ; parts of vegetables, and even insects, 
being occasionally found in it. 
Amber is used for trinkets, particularly in 
Turkey and the East; but the finest speci- 
mens are in the cabinet of the king of Prussia. 
AMBERGRIS resembles amber in several 
chemical qualities. It is a light ash-coloured 
body found on the sea-shores in the East 
Indies. It is opaque, and of a granulated 
structure. It has a light agreeable odour; 
melts with a gentle heat, without suffering 
any change ; and, if farther heated in close 
vessels, it gives an oil like that of amber. It 
also dissolves in spirit of wine, by means of 
heat, and is used in the composition of per- 
fumes. It is not affected by acids. 
The origin of this substance is uncertain. 
It appears to be somewhat similar to that of 
amber. It is found in masses, from one to a 
hundred ounces. The greatest quantity is 
found floating in the Indian ocean ; but we 
also meet with it in our own and in the north- 
ern seas. It is found likewise adhering to the 
rocks, and in the stomachs of the most vora- 
cious fishes; these animals swallowing at par- 
ticular times every thing they happen to 
meet with. It has been particularly found in 
the intestines of the cachalot whale, and most 
commonly in sickly fish, whence it is supposed 
either the cause or effect of disease. We 
often find it in relicts of animal and vegetable 
substances, the bones and beaks of birds, and 
insects ; and as it resembles bees-wax, melt- 
ing like it, it would appear that it has been 
originally bees-wax, which having been buried 
under the surface of the earth, or having 
floated a long time on the ocean, has under- 
gone a considerable change; and we know 
the amazing quantity of bees-wax and honey 
that is sometimes collected by bees in their 
wild state, as in America. In old trees quan- 
tities have been found, sufficient for filling 
several hogsheads; and in rocks and caves 
along the -sea-shore, quantities may be ga- 
thered together ; and by being buried, or lay 
floating on the water/they may undergo a 
A M B 
change, so as to be converted into this sub- 
stance. 
AMBIDEXTER, a person who can use 
both hands with the same facility, and for the 
same purposes, that the generality of people 
do their right hands. 
Was it not for education, some think that 
all mankind would be ambidexters ; and, in 
fact, we frequently find nurses obliged to be 
at a good deal of pains before they can bring 
children to forego the use of their left hands. 
It is perhaps a pity that any of the gifts of 
nature should be thus rendered in a great 
measure useless, as there are many occasions 
in life which require the equal use of both 
hands : such are the operations of bleeding in 
the left arm, left ancle, &c. 
Ambidexter, among lawyers, a juror or 
embracer, who accepts money of both par- 
ties for giving his verdict; an offence for 
which he is liable to be imprisoned, for ever 
excluded from a jury, and to pay ten times 
the sum he accepted of. 
AMBIGENAL hyperbola, a name 
given by sir Isaac Newton to one of the triple 
hyperbolas of the second order, having one 
of its infinite legs falling within an angle 
formed by the asymptotes, and the other 
falling without. See Conic Section. 
AMBIGUITY, in rhetoric and grammar, 
a defect of language, whereby words are ren- 
dered equivocal. 
AMBIT, in geometry, is the same with 
what is otherwise called the perimeter of a 
figure. 
AMBITUS, whence our word ambition, 
in Roman antiquity, the offering for some 
magistracy or office, and formally going 
round the city to solicit the interest and vote 
of the people. 
On these occasions it was not only usual to 
solicit the interest of their friends and others, 
with whom they were personally acquainted ; 
but the candidates, being attended by persons 
of an extensive acquaintance, who suggested 
to them the names 61 the citizens, and thence 
called nomenclatores , or interpretes, macle^ 
application to all they met. J his method of 
suing for offices was deemed allowable, and 
therefore never prohibited by law ; but to 
restrain all undue influence, whether by 
bribery, or by exhibiting games, shews, and 
the like, many laws were enacted, and severe 
fines imposed. 
Ambitus, in music, a name sometimes ap- 
propriated to signify the particular extent of 
each tone, or modification of grave and 
acute. 
AMBLE, in horsemanship, a peculiar pace 
by which a horse’s two legs of the same side 
move at the same time. 
Many methods have been proposed to 
bring a young horse to amble : some try it 
by new-ploughed fields ; some endeavour to 
bring him to amble from the gallop; and 
many use weights:' some attempt to procure 
an amble in hand, ere they mount his back ; 
others, by the help of hind shoes, made on 
purpose ; others, by folding fine soft lists 
about the gambrels of the horse ; and others 
by the trarnei . 
All these methods, however, are attended 
with great danger to the horse ; and the best 
way is to try with the hand, by a gentle de- 
liberate racking of the horse, by helping him 
in the weak part of the mouth with a smooth, 
big, and lull snaffle, and correcting him first 
on one side, then on the other, with the 
calves of the legs, and sometimes with a 
spur. 
AMBLYGON, in geometry, denotes an 
obtuse-angled triangle, or a triangle, one of 
whose angles consists of more than ninety 
degrees. 
AMBO, or Ambon, in ecclesiastical anti- 
quity, a kind qf pulpit, or reading-desk, where 
that part of the divine service called the 
gradual was performed. 
AMBROSE, or St. Ambrose in the wood, 
an order of religious, who use the Ambrosian 
office, and wear an image of that saint en- 
graven on a little plate : in other respects 
they conform to the rule of the Augustins. 
AMBROSIA, the name of a distinct genus 
of plants, with fiosculous flowers, composed 
of several small infundibuliform iloscules, 
divided into five segments ; these, however, 
are barren; the frait, which in some measure 
resembles a club, growing on other parts of 
the plant. 
T his genus belongs to tire mowoecia pen- 
tandria class of Linnaeus. The characters are: 
the male flowers are compound : the com- 
mon calyx is a single-leaved perianthium, the 
length of the florets ; the compound corolla 
is uniform, tubular, fiat, and hemispherical: 
the proper is monopetalous, funnel-shaped, 
and quinquefid: the stamina consist of five 
very small filaments ; the anthers are erect, 
parallel, and pointed: the pistillum has a 
filiform stylus, the length of the stamina; the 
stigma, orbicular and membraiaeous : the re- 
ceptaculum is naked. — Female flowers below 
the male ones, on the same plant, doubled : 
the calyx is a single-leaved pefianthum, en- 
tire (with the belly quinquedentated), one- 
flowered, and persistent : there is no corolla: 
the pistillum has an ovate germen in the bot- 
tom of the calyx ; a filiform stylus, the length 
of the calyx ; and two long bristly stigmata: 
the pericarpium is an ovate unilocular nut : 
the seed is single and roundish. Of this genus 
five species are enumerated- one of which is 
perennial, and may be propagated either by 
cuttings or by seeds. r i he plants are mode- 
rately hardy, so may be exposed to the open 
air in the summer ; and in winter may be 
sheltered in a common green-house with 
myrtles, and other hardy exotic plants. 
AMBROSIAN office, in church history, 
a particular formula of worship in the church 
of Milan, which takes its name from St. 
Ambrose, who instituted that office in the 
fourth century. Each church originally had 
its particular office ; and vjhen the pope in 
aftertimes took upon him to impose the 
Roman office upon all the western churches, 
that of Milan sheltered itself under the name 
and authority of St. Ambrose, from which 
time the Ambrosian ritual has prevailed in 
contradistinction from the Roman ritual. 
Ambrosian chant, in ecclesiastical music, 
differs very little, if at all, from the Gre- 
gorian chant. 
AMBROSIN, a coin formerly struck by 
the dukes of Milan, representing St. Am- 
brose on horseback, with a whip in his right- 
hand. 
AMBROSINIA, a genus of the class and 
order of gynandria polyandria. The essen- 
tial charaCteris: spatbe one-leaved, separated 
by a partition ; stamina on the inner, pistils 
on the outer side of it. We know of but 
one species, a native of Sicily. It requires 
