Spirit of the age. [volume] (Raleigh, N.C.) 1849-1865, 1855-11-21
Written for the Spirit of the Age
FAMILIAR CHEMICAL LETTERS.
ARTICLE VII


investigate the cemoounds which hydrogen
forms with chlorine, iodine, hromine and
lourine These compounds are called hy-
dro5en-acids or hydracids, in contra distinc-
ton to those acids which contain oxygen,
called oxy-acds.
Hydrogen and chlorine. When equal vol
nmes of hy drosen and chlorine arc mixed
and exposed to light, they ..slowly combine
ansl form hyirochlnric or nurlatic acid gas.
Of this combination it has been remarked by
Gsz, Lussac and Thenard, that if the mix
ture be exposed to direct solar rays, detona-
ton frequently ensues. This gas was first
discovered by DR.. Priestly In 1Y72; it is gen.
orally prepared by acting upon common salt
with sulphuric acid. For small experiments
on this Gas-)''tain small glass retort, and
fill it about with common salt; the sulphu-
ric acid should then be added in quantity just
sufficient to cover the pieces Of salt; the gas
is Immediately eliminated and when its evo-
luton slackens, it may be quickened by the
gentle heat of lamp. By this means we
produce pure muratic acid gas. Although
permanently gaseous at all ordinary temper
atures. Mr.. Faraday, Of London, has sue
ceeded in liquifying this gas by applying to
it pressure equal to 40 atmospheres or 600
lbs. per square inch. With this immense
pressure, muriatic acid gas becomes converted
into fluid having refractive power slight
ly inferior to that of water. Hydrochloric
acid gas is perfectly unacceptable; it extin-
guishes the fame of a candle, and is itself
uninfamable Its principal feature is its
strong attraction for water. This gas is very
soluble in water; that liquid takes up 480
or 500 times its bulk of hydrochloric acid
gas; its specific gravity at the same time
being increased from 10 to 1910. The
common muriatic acid of commerce is So
luton of this gas in water or more properly
speaking, water saturated with this gas
! 100 cubic inches of water are capable of alb
sorbing $4,000 cubic inches Of this gas -
whereby the volume Of the water is incr; ased
| from 100 to l42 cubic inches This vast
condensation is accompanied with great
production of heat whence it becomes ne
cessary to apply artificial refrigeration, es-
pecially if so strong an acid as the above is
to be prepared; but in general the muriatic
acid of commerce contains considerably less
than 40 parts by weight, of acid gas, in the
hundred; whilst the above stronger acid
contains AZ, SO per cent by weight Of the pure
gas. The preparation of this acid is chiefly
effected In this country by acting upon sea-
salt in hemispherical iron pots or OFFENDERS,
with concentrated sulphuric acid in the pro-
} portion Of 6 parts of the salt to of the acid
The mouth of the pot is usually covered with
a slab of selicious freestone perforated with
two holes of about two inches IN diameter
each into one of which the acid is poured
by funnel, in successive portions; whilst
in the other a bent glass, or porcelain tube
is fixed, for conducting the disengaged by
:, drochloric-acid gas into series of jars, filled
Q / full with water, called Woulfe's appara-
S tus." These jars are connected together by
n fy,h of rth hat, ~
j. in one becomes saturated, the gas passes on
i to the next, and SO on, till all the jars
d have received their quantum Of the gas. A
: week is commonly employed for working off
|. each pot, no eat being applied to it till the
5 second day. Having learned the mode of
IS preparation of this gas or acid, it becomes
L US now to inquire what decomposition has
), taken place IN the iron pot. Let us look in !:
j. this substance we see is not like the original
O. salt placed there before the operation COM
g mesced. No, this is quite different SUBJ
Id stance, and is called sulphate of soda-whilst
y, common salt is called chloride Of sodium
n Well what has become of the chlorine? Let
n me explain: common salt, as all know, con-
ty sists of chlorine and sodium; all the sui phu.
or rlc acid of commerce contains a considerable
d, amount of water when the sulphuric acid
a comes in contact with the common salt, the
a water of the sulphuric acid becomes decom
it posed its oxygen unites with the sodium o.
g, the salt and forms soda, which in its turr
ar unites with the sulphuric acid and form:
us sulphate OF soda; the hydrogen of the water
= being now free, and finding the chlorine O
~ the common salt free, also untes with tha
lie, gas, and wehave, as the result of that union
tn hydrochloric or muriatic acid, and this being
ce gas, is forced over into the receivers places
= for its reception. The result left in the 20
he is, as have already said, sulphate of soda
bit. or Glauber's salt. When this acid Of com
nd merce is pure, it is coloress, but it generall
'as has yellow hue, caused by particles of tn
a late that have accidentally fallen into it, Q
ors sometimes from traces of iron. Dr. Thom
lie son suggests that the yellow tint may b
ng caused by trace of bromine derived durin
ty, decomposition from the salt. Almost all th
= muriatic acid of commerce is contaminate
all with iron and sulphuric acid, and sometime
W. nitric and sulphurous acid; traces of arsen
om are also frequently found in many samples
We. the presence of this substance is easily e.
planned to US when we remember that niue
ght of the sulphuric acid used is made from a
or senical pyrites. Uneombined muriatic &C
lin exists in small quantities in the human ga
rn- trio juice; and it is only found in nature
'me an occasional volcanic product. The prime
pal uses of this acid are as a medicine, al
am, in some of the arts, whore it is employed
the solvent of metals. 1t is extremely mi
ded rious to vegetation; mixed with %, 900 tim
ms. its volume of atmospheric air it proves fatal
q to plants" shrivelling and killing all t
ans leaves in "a hours" The next compouI
Tres which comes under our notice is
hair Hydrogen with Iodine. This compound
rom called hydriodic acid: it was first examin
ress by Sir Humphrey Davy and Gay Lussac.
and This acid may be formed by the direct uni
J re of its elements thus, by passing mixture
hro' hydrogen gas and Iodine vapor through
'ess- red hot tube; but it is most easily procul
de- by the mutual action Of water, phosphoro
'ver: and Iodine: or what is exactly the sa
had thing. by the action of iodide of phosphorc
hum on water. But as the preparation of /
&, ere substance is interesting only to the scient
aged chemist would refer those who wish to
me tain more knowledge of this BODY to 50
for chemical Text book. Hydriodic acid gas
hem, colorless, sour, exhales fumes in the air. .
oner and its smell much resembles that of hyC
: chloric acid. 1t extinguishes fame, an
not itself infammable. 1t is liouifable
der pressure, and when its temperature is
t one duced to 600 it becomes transparent co
-orld- less solid. The experiments of GAY Lus
ty.- have proved that this gas is analogous ir
cunt composition to hydrochloric acid gas;
lv;nr ia m cav that II CONSISTS oF ono ,oJ,, -,