The liquid acid, of which we are about to treat, is a solution of
muriatic acid gas in water; when of the specific gravity 1·16, according
to _Davy_, it contains 32·32 per cent. of the gas, which recent
experiments have proved to be a compound of _Chlorine_ (oxy-muriatic
acid) and _hydrogen_, in equal volumes. It has accordingly received a
name expressive of its composition, and is called _Hydro-chloric acid_.
Its odour is strong and peculiar; when exposed to the air it emits white
fumes; its taste is intensely sour and caustic; it is, however, the
weakest of the three mineral acids, and no remarkable elevation of
temperature is produced by dilution. It readily combines with potass,
soda, &c. and furnishes a class of salts which may be easily recognised
by their characters.
_Symptoms of Poisoning by Muriatic Acid._
As the effects of muriatic acid do not differ from those which have been
described, as the consequences of poisoning by the other mineral acids,
it will be unnecessary to enumerate them. _Orfila_, however, remarks,
that the patients who have swallowed a certain quantity of it, emit, in
the first moments of the accident, a thick smoke of a white colour, and
very pungent smell.
_Chemical processes for the detection of Muriatic Acid._
This acid, in its free state, immediately announces its nature by the
fumes which it emits. When the acid, however, exists in a more
questionable shape, as in the matter vomited by the patient, or in that
found in the digestive canal after death, it will be necessary to
saturate the liquid part with pure potass, and to boil it for some time,
when we shall obtain a fluid, from which the nitrate of silver will
throw down a dense precipitate. By evaporation, we shall obtain a
crystallized muriate, which may be identified by the following tests: 1,
When concentrated sulphuric acid is poured upon it, a brisk
effervescence is immediately occasioned, and the muriatic acid is
disengaged in the form of white vapours, which are thick, and of an
excessively pungent smell. 2, If instead of employing concentrated
sulphuric acid, this acid be used in a state of dilution, and the
muriate be mixed with some substance which easily yields its oxygen, the
muriatic acid will be decomposed, its hydrogen, combining with the
oxygen so as to form water, while the chlorine will be disengaged, and
by its pungent and peculiar odour at once announce the nature of the
acid under examination.