AMN 
A MM 
to the temperature of — 46° it crystallizes ; 
and when suddenly cooled down to — 68°, it 
assumes the appearance of a thick jelly, and 
has scarcely any smell. It follows from the 
experiments of Mr. Davy, that a saturated 
solution of animonia is composed of 
74.63 water. 
25.37 ammonia. 
100.00 
Charcoal absorbs ammoniacal gas, but does 
not alter its properties while cold. But 
when the gas is made to pass through red 
hot charcoal, part of the charcoal combines 
with it, and forms a substance known by 
the name of prussic acid. Ammonia is not 
acted on by azote ; but it combines rapidly 
with muriatic acid ; the two gases concret- 
ing into the solid salt called muriate of am- 
monia. Ammonia does not combine with 
the metals f but it changes some of them 
into oxydes, and then dissolves them. Li- 
quid ammonia is capable of dissolving the 
oxydes of silver, copper, iron, tin, nickel, 
zinc, bismuth, and cobalt. When digested 
upon the oxydes of mercury, lead, or man- 
ganese, it is decomposed, water is formed 
by the union of the hydrogen of the ammo- 
nia with the oxygen of the oxides, and azo- 
tic gas is omitted. If a considerable heat 
be applied, nitric acid is formed at the same 
time with water. Several other oxydes are 
also partly deoxidized when ammonia is 
poured into their solutions in acids. See 
Alkali, Chemistry, &c. 
AMMONIAC, in chemistry, a gum resin 
brought from the East Indies. It is sup- 
posed to be a species of the Ferula. It is 
in small, pieces agglutinated together, and 
has a yellowish white colour. Its smell is 
like that of the galbanum, but more plea- 
sant. Its taste is a nauceous sweet mixed 
with bitter. It does not melt. Water dis- 
solves a portion of it ; the solution is milky, 
but gradually lets fall a resinous portion. 
One-half is soluble in alcohol. Its specific 
gravity is 1.2. Neither alcohol nor water 
distilled off it, brings over any thing. 
AMMONITRUM. See Glass. 
AMMOPHILA, in natural history, the 
, sand-wasp, a genus of insects of the order 
Hymenoptera: gen. char, snout conic, in- 
flected, concealing a bifid retractile tubu- 
lar tongue : jaws forcipated, three itoothed 
at the tip : antennae filiform in each sex, 
with about 14 articulations : eyes oval : 
wings plain: sting pungent, concealed in 
the abdomen. This genus is separated 
from that of the sphcx, on the authority of 
the Rev. Mr. Kirby : in their manners awl 
economy, they resemble each other ; and it 
is probable that many more of the spheges 
might, with propriety, 'be removed into this 
genus. There are four species : A. vulga- 
ris, inhabits Europe in sandy, sunny banks, 
where it digs a hole with its fore-feet and 
buries the carcase of the larva of a moth or 
half dead spider, in the body of which it has 
deposited its eggs, and then covers up the 
orifice. 
AMMUNITION, a general term for all 
warlike provisions, but more especially pow- 
der, ball, &c. 
Ammunition, arms, utensils of war, gun- 
powder, imported without licence from his 
Majesty, are, by the laws of England, for- 
feited and triple the value. 
And again, such licence obtained, except 
for furnishing his Majesty’s public stores, is 
to be void, and the offender to incur a pra- 
munire, and be disabled to hold any office 
from the crown. 
AMNESTY, in matters of policy, an 
act by which two parties at variance, pro- 
mise to pardon and bury .in oblivion all that 
is past. 
Amnesty is either general and unlimited, 
or particular and restrained, though most 
commonly universal, without condition or 
exceptions ; such as that which passed in 
Germany at the peace of Osnaburg in the 
year 1648. 
Amnesty, in a more limited sense, de- 
notes a pardon granted by a Prince to his 
rebellious subjects, usually with some ex- 
ceptions : such was that granted by Charles 
11. at his restoration. 
AMNIOS, in anatomy, a thin pellucid 
membrane, w r hich surrounds the foetus. 
The foetus in the uterus is enveloped in a 
peculiar membranous covering, to which 
anatomists have given the name of amnios. 
Within this there is a liquid, distinguished 
by the name of the liquor of the amnios 
which surrounds the foetus on every part. 
This liquid, as might have been expected, 
is very different in different animals; at 
least the liquor amniiin women and in cows, 
which alone have hitherto been analysed, 
have not the smallest resemblance to each 
other. The liquor of the amnios of women 
is a fluid of a slightly milky colour, a weak 
pleasant odour, and a saltish taste. The 
white colour is owing to a curdy matter sus- 
pended in it, for it may be obtained quite 
transparent by filtration. Its specific gra- 
vity is 1.005. It gives a green colour to 
the tincture of violets, and yet it reddens 
