Spirit of the age. [volume] (Raleigh, N.C.) 1849-1865, 1855-09-12
COM M UNICATIoNS N s

Familiar Chemical Letters.
REsPEcTTuLLr DEDICATED TO MISS LAURA MURPHY
ARTICLE ".
In Article III, full description of the
process for the manufacture OF Iodine was
given. We will now examine some Of the
properties of this singular element. At
ordinary temperatures, Iodine is solid, of
dark steel or blush black color, it forms
beautiful crystals when carefully sublimed,
having q metallic lustre, but incapable of
conducting electricity. IL is therefore a \
non-conductor. 1t is soft and pliable, its
specific gravity, according to Gay Luzzac,
is 4,946 and its specific heat according
to Regnault, is 054l2. 1t produces yel- |
low stain upon the skin, its taste is acrid, !
its smell somewhat resembles that of dilu-
ted chlorine. 1t is extremely volatile
when moist at ordinary temperatures in
open bottles, it passes away as vapor; it
should therefore be kept in well ground
stoppered bottles. Iodine is sparingly So
luble in water, requiring 1000 times its
weight Of water for complete solution; the
color Of this solution is pale brown it is
much more soluble in alcohol and ether,
forming with these fluids deep brown solu-
tions.
The peculiar violet color of Iodine and
its vapor, has already been noticed this
in many cases is sufficient evidence of its
presence more delicate test, however,
is necessary, and think the test discovered
by Colin and Gaultier de Clanbry, is the
most delicate we have 1t is this when
a solution Of starch is brought into contact
with solution of Iodine, deep blue COM
pound is formed the depth of the color,
and amount of the blue compound formed,
varying according to the strength of the so.
luton Of Iodine used. According to Strom-
eyer, liquid, containing one 450,000th
Its weight of Iodine, receives blue tinge
when solution of starch is added to it
To detect Iodine by this test, we must al
ways be certain that the Iodine exists in a
free state and to ensure this, it would be
better always to add few drops of nitric
acid previous to adding the starch where
the proportion Of Iodine is very minute, 9
few minutes elapso before the discoloration
ensues. As Iodine frequently exists in
many Of our Mineral Springs, | give the
following as a simple process by which
the presence of this substance may be de-
tected Take clean vessel, Zone OF porce.
lain is preferable, and pour into il known
quantity of the water to be examined, say
gallon set the vessel with its contents
over a lamp or fire and evaporate the wate
to the bulk of or ozs., add few drop
ofnitric acid and then the solution of starch
if Iodine is present, blue color will b
produced if not, no action will take place
The principle use as yet made of lodin
and its compounds, is in medicine in owe
doses it is however, an irritant poison
The rich color of some of its combination
has also led to its employment in the art {
Calico printing. As much of the Iodiu
Of commerce is adulterated with plumbag,
sulphuret of antimony. and perocide {
manganese, would give here few hint
to the medical man; never use Iodine will
out previously testing it. The tests for i
purity are two:
1st, Pure Iodine is entirely soluble
alcohol.
End, Pure Iodine is entirely sublime
by heat.
BY these two tests, if there are any
dulterations in the Iodine, they may be q
tected, undesolved in the first case, al
unsublimed in the second. We DOW cor
to examine the compounds which lodi
forms with oxygen; these are four, namel
one oxide and three acids; but of these, on
two have been duly examined Oxide
Iodine, the name of the first mention
compound, was discovered by Sement
while attempting the direct combination
iodine with oxygen a portion of it,
says, is formed when Iodine is frequent
heated in atmospheric air, but it is me
rapidly produced by presenting Iodine a
oxygen to each other at high temperatu
1t is a very volatile substance and is mu
more soluble in water than Iodine itsC
it is also very soluble in alcohol, pro,
cling amber-colored solutions. It's com
sition is not correctly known. OF the O
er two, one only need be mentioned, as
other is at present mere Chemical CT
osity. Iodic Acid this acid is compo
Of one atom Of Iodine united with five ate
of oxygen it is formed by boiling iod
for several hours with about five times
weight of strong nitric acid. The MKT
should be introduced into tube, CLOSED
one end, and the Iodine as it sublime
the upper part, constantly returns into
acid till it disappears on carefully driv
off the nitric acid by heat the Iodic
remains. This acid acts powerfully u
the metals and produces with oxides c
Of salts called iodates. We next com
the compounds which Iodine forms !
chlorine; these are two in number, nam
Chlorine Of Iodine, and Perchloride Of
dine. These compounds are of very
interest to US the only use to which
have been applied is in the Daguerreo
process, but in this they are very valui
having been found to give more del
tints upon silver plate than Iodine O
other compounds. We have now fni
the Chemical history of Iodine and
next TO that of Bromine.
Bromine was discovered by Mr.. Ba
Of Montpelier in 1926; it takes its |
from Greek word referring to its pee
ordor It was at first discovered in
water in which it probably exists il
state of Bromide Of magnesium; its
tive proportion, however, is exceed
minute 100 bbls. of sea water contai
only 81 grs of bromine. It has
found in many brine springs, as exam
we have Theodorshal, Wilhelmshall,
iuCen Sedan Raden Raden and R