JSO 
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of the Persian empire, as the grand visier is 
of the Turkish empire. 
ATHAMANTA, in botany, a genus of 
the pentandria digynia class and order, and 
in the natural method ranking under the 45th 
-order, umhellats'. The fruit is oblong and 
striated, and the petals are inflected and 
emarginateck Of this genus there are nine 
species, but none of them merit particular- 
notice, except the athamanta cretensis, or 
tlaucus creticus, which grows wild in the Le- 
vant and the warmer parts of Europe. The 
flower-stalk rises about two feet high, sending- 
out many branches. These have white 
flowers. The seeds have a warm biting taste, 
with an agreeable aromatic smell. They are 
said to be carminative and diuretic, but 
are little used in practice. 
ATHANASIA, goldilocks, a genus of the 
polygamia aequalis order, and syngenesia class 
of plants; and in the natural method ranking 
tinder the 49th order, composite discoides. 
’['he receptacle is chaffy; the pappus or 
down chatty, and very sliort ; and the calyx 
is imbricated. There are 20 species, all 
tender plants except one ; and none of them 
possessed of beauty, or any remarkable pro- 
perty yet discovered. 
A’Fi lANATf, in Persian antiquity, a body 
of cavalry consisting of 10,000 men, always 
complete. They were called athanati because 
when one of them happened to die, another 
was immediately appointed to succeed him. 
ATHANOR. bee Chemistry. 
ATHELING, adding, edli-ng, (tiding, or 
■ethding, among our baxon ancestors, was a 
title of honour properly belonging to tire heir 
apparent, or presumptive, to the crown. 
ATHENiEA, in botany, a genus of the 
class and order octandria monogynia ; the cal. 
is coloured, five-parted ; corolla none; bristles 
eight, feathered between the filaments ; stigma 
five-parted; caps- globose, one-cell ed, three- 
y a lved; seeds three to live. 
There is one species, a branching shrub of 
Guinea; the bark, leaves, and fruit, are sharp 
and aromatic, called caffe diable by the Cre- 
oles. . . , , 
ATIIEN/EUM, ill antiquity, a public place 
where the professors of the liberal arts held 
their assemblies, the rhetoricians declaimed, 
and the poets rehearsed their performances. 
The three most celebrated athemva were 
those at Athens, at Rome, and at Lyons, the 
second of which was built by the emperor 
Adrian. 
ATHERINA, in ichthyology, a genus of 
abdominal fishes, distinguished by having the 
upper jaw rather flat, six rays in the gill 
membrane, and a silvery stripe on each side 
of the body. There are five species of this 
genus: the most remarkable are ; • 
1. Atherina hepsetus, with about 12 rays 
iu the fin next the anus. It is found in the 
Mediterranean. It is also very common in 
fhe sea near Southampton, where it is called 
.a smelt* The highest season is from March 
lo the latter end of May, or beginning of 
June ; in which month it spawns. It never 
deserts the place; and is constantly taken, 
except in hard frost. It is also found on 
other coasts of our island. 1 lie length is 
above A-\ inches, and the tail is much forked. 
The fish is semi-pellucid, covered with scales ; 
the colour silvery, tinged with yellow; be- 
neath the side line is a row of small black 
spots. 
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2. Atherina menidea, has 24 rays in the 
fm next the anus. This is a very pellucid 
fish, with many black points interspersed ; it 
has many teeth in the lips, but none in the 
tongue or jaws. It is found in the fresh wa- 
ters of Carolina, and spaw ns in April. 
ATHEROMA, in* medicine, a tumour 
without pain or/liscolouring of the skin ; con- 
taining, in a membranaceous bag, matter like 
pap, intermixed with hard and stony cor- 
puscles, &c. It is cured by incision. 
ATHLETfE, in aniiquitv, men of remark- 
able strength and agility, disciplined to per- 
form in the public, games. 
ATLANTIDES, in astronomy, the same 
with Pleiades. They are so called as being 
supposed by the poets to be the daughters ot 
Atlas, who were translated into heaven. 
ATLAS, in anatomy, the name by which 
some call the first vertebra of the neck ; so 
called in allusion to Atlas. 
Atlas denotes a book of universal geo- 
grapliy, containing maps of all the known 
parts of the world. 
Atlas, in commerce, a sort of silk or sat- 
in manufactured in the East Indies, in which 
gold and silk are so wrought together, as no 
workman in Europe can imitate. In China 
they weave long slips ot gilt paper into their 
silk’s, 'l'lie same slips of paper are twisted 
about silk threads so artificially, as to look 
finer than gold thread, though ol no great 
value. 
ATMOSPHERE, a term used to signify 
the whole of the fluid mass, consisting of air, 
aqueous and other vapours, electric fluids, 
&c. which surrounds the earth to a consider- 
able height ; and partaking ot all its motions, 
both annual and diurnal. 
The composition of that part of our at- 
mosphere properly called air, was till within 
a few years but very little known. Formerly 
it w r as supposed to be a simple, homogeneous, 
and elementary fluid; but the experiments 
of Dr. Priestley and others have discovered, 
that the atmospheric air is in reality a com- 
pound, and may be artificially produced by 
the union of two other kinds of air, viz. oxy- 
gen, or pure air, and nitrogen or azotic gas. R y 
accurate experiments, the air that we usually 
breathe is composed of only one-fourth part 
of oxygen air, or perhaps less; the other 
three parts, or more, consisting of azotic gas 
or nitrogen. 
Atmosphere, uses of. The uses of 
the atmosphere are so many and great, that 
it seems indeed absolutely necessary, not 
only to the comfort and convenience of men, 
but even to the existence of all animal and 
vegetable life, and to the very constitution of 
all kinds of matter whatever, and without 
which they would not be what they are ; for 
by it we live, breathe, and have our being ; 
and by insinuating itself into all the vacuities 
of bodies, it becomes the great spring of most 
of the mutations here below ; as generation, 
corruption, dissolution, &c. and without 
which none of these operations could be car- 
ried on. 
By the mechanical force of the atmosphere 
too, as well as its chemical virtues, many 
necessary purposes are answered. We em- 
ploy it as a moving power, in the motion of 
ships, to turn mills, and for other such uses. 
And it is one of the great discoveries of the 
modern philosophers, that the several mo- 
tions attributed by the antients to a fuga 
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vacui, are really owing to the pressure of the 
atmosphere. Galileo, having observed that 
there w as a certain standard altitude, beyond 
which no water could be elevated by pump- 
ing, took an occasion then to call in question 
the doctrine of the schools, which ascribed the 
ascent of water in pumps, to the abhorrence 
of a vacuum, and instead of it lie happily sub- 
stituted the. hypothesis of the weight and 
pressure of th • air. It was with him indeed 
little better than an hypothesis ; since it had 
not then those confirmations from experi- 
ment, afterwards found out by his pupil Tor- 
ricelli, and other succeeding philosophers, 
particularly Mr. Boyle. 
Atmosphere, salubrity of. On the 
tops of mountains the air is generally more 
salubrious thtin in pits or very deep places. 
Besides the difference arising from the mere 
difference of altitude, the salubrity of the at- 
mosphere is greatly affected by many other 
circumstances. The air, when confined or 
stagnant, is commonly more impure than 
when agitated and shifted: thus, all close 
places are unhealthy ; and even the air in a 
bi d-chamber is less salubrious in a morning, 
after it has been slept in, than in the evening. 
Dr. White, in oj. 68 Philos. Trans, gives an 
account of experiments on this quality of the 
air; and remarks one instance when the air 
was particularly impure, viz. Sept. 13, 1777; 
when the barometer stood at 30° 30, the ther- 
mometer at 69°; the air being then dry and 
sultry, and no rain having fallen for more 
than two weeks. A slight shock of an earth- 
quake was perceiwqd that day. In vol. 70 
of the same Transactions, [Dr. Ingenho-usz 
gives an account of some experiments on 
this head, made in various places and situa- 
tions : he finds, “ that the air at sea, and 
close to it, is in general purer, and titter for 
animal life, than the air on tire land ;” but 
the doctor did not find much difference be- 
tween the air. of the towns and of the count ry, 
nor between one town and another. I he 
abbe Fontana made nearly the same conclu- 
sions, from accurate experiments, asserting, 
“ that the difference between the air of one 
country and that of another, at different times, 
is much less than what is commonly believed; 
and yet that this difference in the purity of 
the air at different times, is much greater than 
the difference between the air of the different 
places observed by him.” Finally, M. Ion- 
tana concludes, that “ nature is not so partial 
as we commonly believe. She has not only 
given us an air almost equally good every- 
where at every time, but has allowed us a 
certain latitude, or a power of living and 
being in health, in qualities of air which differ 
to a certain degree. By this it is not meant 
to deny the existence of certain kinds of nox- 
ious air in some particular places; but to own 
that in general the air is good every where, 
and that the small differences are not to be 
feared so much as some people would make 
us believe. Nor is it meant to speak here of 
those vapours and other bodies which are ac- 
cidentally joined to the common air in parti- 
cular places, but do not change its nature and 
intrinsical property. This state of the air 
cannot be known by the test of nitrous air ; 
and those vapours are to be considered in the 
same manner as we should consider so many 
particles of arsenic swimming in thy atmo- 
sphere. In this case it is the arsenic, and not 
the degenerated air, that would kill the aai- 
