CHEMISTRY. 
340 
compose it very readily ; hence this salt is 
highly useful to detect the presence of these 
acids in any mixture. 
Of oxygenated in uriatic acid. — Oxygenated 
muriatic acid is muriatic acid with an excess 
of oxygen. By this, however, the acid pro- 
perties of the muriatic acid are not increased, 
as is the case with other acids, but, on the 
contrary, diminished. In the state of gas, 
when absorbed by water, it forms liquid oxy- 
genated muriatic acid, which, in a liquid 
form, is of a greenish -yellow colour. It has 
a bitter taste, and a very suffocating odour. 
Instead of reddening blue vegetable colours, 
it has the remarkable property of destroying 
them entirely. It thickens oils and animal 
fats, and renders them less disposed to com- 
bine with alkalies. It is readily obtained by 
the distillation of muriatic acid with sub- 
stances containing much oxygen, such as the 
oxyds of metals, particularly the native oxyd 
of manganese. 
When it is exposed to the light, oxygen 
gas is separated, and the acid is reduced to 
the state of ordinary muriatic acid. It re- 
moves the stain of common ink, though it 
does not affect printers’ ink. It is therefore 
used for cleaning old books and prints. Half 
an mince of minium being added to three 
ounces ot muriatic acid, will render it fit for 
this purpose. The muriatic acid, taking 
oxygen from the minium, or red oxyd of 
lead, is converted into oxygenated muriatic 
acid. 
Nitro-muriatic acid, called formerly aqua 
regia, is an acid analogous to oxygenated 
muriatic acid. it is produced by adding 
muriatic acid to nitric acid, in the proportion 
of one part of the former to two of the latter. 
During this combination an effervescence 
takes place, heat is set free, and oxygenated 
muriatic acid gas is evolved ; the action may 
be assisted by the application of heat. The 
mixture becomes yellow. This acid has the 
properly of dissolving gold and platina, which 
cannot be acted upon by any other acid ; for 
the muriatic acid attracts part of the oxygen 
of the nitric acid, being thus converted partly 
into nitrous acid and partly into nitrous gas, 
whilst the muriatic acid becomes converted 
by this addition of oxygen into oxygenated 
muriatic acid, or nitro-muriatic acid. The 
same combination may be produced by mix- 
ing together oxygenated muriatic acid and 
nitrous gas. Oxygenated muriatic acid may 
be combined with a great number of the sali- 
fiable bases; the salts which it forms detonate 
with carbon and with several metallic sub- 
stances. These detonations are exceedingly 
dangerous, because the oxygen entering into 
the muriatic acid, with a large quantity of 
caloric, its expansion gives rise to violent 
explosions. 
Oxygenated muriate of potash is made by 
introducing the oxygenated muriatic gas 
into a solution of potash ; its crystals, as well 
as those of the common muriate, being form- 
ed on evaporation in the dark. It gives a 
faint taste, with a sensation of coldness in the 
mouth; the crystals have somewhat of a sil- 
very appearance, and emit light by attri- 
tion. It is decomposed by the action of 
light, parting with its oxygen, and becoming 
simple muriate of potash. Heat also sepa- 
rates its oxygen from it, in the form of oxy- 
gen gas, 100 grains yielding 75 cubic inches 
of oxygen gas. When three parts of oxy- 
genated muriate of potash, and one of sul- 
phur, are triturated in a mortar, the mixture 
detonates violently. The same effect is pro- 
duced when the mixture is struck with a 
hammer on an anvil. 
Phosphorus detonates with oxygenated 
muriate of potash with a prodigious force. 
Similar effects are produced with other in- 
flammable substances, or with metallic bo- 
dies. The oxygenated muriate of potash 
increases the blackness of ink; and the co- 
lours of log-wood, weld, cochineal, and ar- 
chil, are improved by it, if no heat is em- 
ployed. When employed in the composition 
of gunpowder, instead of nitre, the effects 
produced by its ignition are augmented in a 
very great degree, and the mixture will ex- 
plode by mere trituration. 
In tliis and other salts formed in the same 
way, the acid gets a still greater dose of oxy- 
gen, and is denominated hyper-oxymuriatic 
acid ; but it cannot be separately exhibited. 
Of carbonic acid . — This acid, already no- 
ticed under carbonic acid gas, exists in the 
gaseous state; and in combination with differ- 
ent bases if constitutes carbonates. 
Carbonate of potash, formerly called mild 
vegetable alkali, is made by exposing a solu- 
tion of alkali to the carbonic acid gas until 
saturated. It has now less of the urinous 
taste, but still changes the blue colour of 
violets to a green. It does not attract mois- 
ture from the air, but rather parts with its 
water of crystallization. By exposure to 
heat it loses its acid, is rendered pure alkali, 
and is capable of uniting with siiex, and 
forming glass. It is decomposed by quick- 
lime, and by all the acids. 
Carbonate of soda was formerly termed 
mild mineral alkali. It is decomposed by 
quick-lime, by the acids, and by lire, in the 
same manner as the former carbonate. 
Carbonate of ammonia, or concrete vola- 
tile alkali, may be obtained from many ani- 
mal substances, but it is not found naturally ✓ 
It is formed by the combination of carbonic 
acid with ammonia. When the muriate of 
ammonia is heated with carbonate of lime, 
the products are muriate of lime and carbo- 
nate of ammonia, which lattef sublimes in a 
solid form. 
Carbonate of lime, called also mild calca- 
reous earth, chalk, &c. is formed by the com- 
bination of carbonic acid and lime. It has 
not been crystallized by art, although found 
variously crystallized in its native state. By 
intense heat the acid is disengaged, and pure 
lime remains. It is decomposed by almost 
all the acids, their superior degree of attrac- 
tion for lime forming other calcareous salts, 
the carbonic acid escaping in a gaseous form, 
and occasioning effervescence. 
Carbonate of barytes has no taste, is not 
altered in the air, is almost insoluble in water, 
but is decomposed by heat and by ail the 
acids. It is poisonous. 
Carbonate of magnesia, or the common 
magnesia of the shops, is obtained by preci- 
pitation from the sulphate of magnesia. It 
is soluble in water in the proportion of seve- 
ral grains to an ounce. It loses its water and 
acid by calcination, the residue being pure 
magnesia, sometimes called calcined mag- 
nesia. See Carbon. 
Of fluoric acid . — The composition of this 
acid is unknown. In a gaseous state it forms 
fluoric acid gas ; united to water, it constitutes 
liquid fluoric acid. It exists completely form- 
ed in fluate of lime, known under the name of 
floor, or Derbyshire spar. It is combined 
in it with calcareous earth, forming an inso- 
luble salt. To obtain this acid alone, and 
separated from its base, put fluorspar into a 
leaden retort, and pour over it sulphuric 
acid ; adapt a leaden receiver to the retort, 
half-filled with water, and expose the retort 
to a gentle heat. The sulphuric acid seizes 
ou the basis of the spar, and forms with it 
sulphate of lime ; and the fluoric acid passes 
over in the state of gas, and is absorbed by 
the water in tin* receiver. If it is received 
in a mercurial apparatus, it will pass over in 
the state. of gas. 
The distinguishing property of the fluoric 
acid is its power of dissolving siiex. Its odour 
resembles muriatic acid. When exposed to 
moist atmospheric air, it emits white fumes. 
Its action upon all inflammable substances 
is very feeble ; it does not afford oxygen to 
them. It has no action upon most of the 
metals, but it dissolves many of their oxyds. 
ft must be kept in well-closed leaden or tin 
bottles, or glass phials, coated within with 
wax or varnish. It is employed for etching 
on glass. See Fluor. 
Of boracic acid . — The boracic acid, before 
known under the name of Homberg’s sedative 
salt, is a concrete acid extracted from borax, 
a salt brought from 1 ndia. Its base is unknown . 
It exists in brilliant, glittering, white scales, 
soft, and unctuous to the touch. Its taste is 
bitterish, with a slight acidity. When mixed 
with burning 'spirit of wine, it causes a green, 
surrounded with a white flame. To extract 
boracic acid from borax, the latter must be 
dissolved in boiling water; the liquor is then 
to be filtred while very warm, and sulphuric 
acid poured into it : this acid seizes on the 
soda of the borax ; and the boracic acid, being 
separated, becomes free. By cooling it may 
be obtained under a crystallized form. 
Borate of soda, or borax, is formed by the 
combination of the boracic acid with soda. 
It is found in a crystallized state at the bot- 
tom of certain salt-lakes, in a barren volcanic 
ciistrict of the kingdom of '1 hibet. A still 
purer kind comes from China. It is obtained 
in a pure state by a second crystallization, 
being previously calcined to destroy the 
greasy matter. When purified, it is white 
and transparent. It has a cooling taste, and 
renders the blue vegetable infusions green. 
Exposed to a moderate heat, it melts with 
its water of crystallization ; and is reduced 
into a white opaque light mass, when it is 
commonly called calcined borax. It serves 
as a flux to vitrifiable earths ; it also vitrifies 
clay, but less completely. It is employed in 
forming reducing fluxes ; and it may also be 
used in producing the fusion of glass. In 
soldering metals, it is highly useful, cleansing 
the surface of the metal, and assisting the 
fusion of the solder. See Borax. 
. Ofmellitic acid . — A yellow mineral some- 
what resembling amber, found at Arten m 
Thuringen, has been found by Klaproth and 
Vauquelin to consist of alumina combined 
with a peculiar acid, which (from tnellite the 
name of the mineral) is called the mellitic 
acid. It is crystaHizable , soluble in water, 
decomposable by heat, and forms with the 
salifiable bases peculiar salts called mellats. 
Of arsenious acid . — Formerly chemists 
were embarrassed with the nature of the poi- 
sonous substance known in commerce by the 
name of white arsenic. Experiments have 
shewn that this substance is the metal arsenic,. 
