The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1836-12-30 00:00:00

spade was covered with a film of copper. The Irish inan,-whPn
he saw this metainorphesis, thought that the faries had turoeo
his spade into gold. 'This excited attention, and it was found
that any piece of bright iron thrown flit 0 the water would attract
copper. After this, pieces of scrap iron were thrown into the
aster to precipitate the etyper, and it is said that the copper
obtained by lois mode, exceeded in value that extracted from
the ore. Saphate and nitrate Of copper are employed in the
compasition of many of our. pigments. There is a remarkable
I peculiarity about nitrate of copper, winch appaars capable of a
simple and satisfactory explanation. If we take pure nitrate
of copper reduced to powder, and fold it up in tin Aid, no action
willtake place. but if water be previously sprinkled upon it,
a singular effect will be produced. The water will in a few
minutes boil, and minute sparks of fire will be ejected froth., the
extremity -of the coil. Our tests for the • detection of copper
are very fewin number, but very satisfactory. They are solu-
tions of Ferro-cyanuret of potassium, which gives a rich churn-
late precipitate, and of ammonia, which yeilds a blue precipi-
late. Either of these will indicate very minute quantities of
copper in solution. • We have many very valuable alloys of
copper, perhaps the best known are brass, bell metal, and gun
metal. It will be remembered that it was stated in a former
lecture, in eary times the' alloy called brass was not the brass
of modern times, but it was an impure copper, alloyed with tin,
which formed a very durable and hard alloy. In the scriptures,
brass is described as being exceedingly hard, aonorous, and
durable. Now copper is by means sonorous, having very little
elasticity, nor is it hard or comparatively durable. Brass in
modern times is made of an alloy of pure copper, and pure
Zinc. It is true that in Rome, brass was made by an admixture
of impure copper,' with the, earth called cadmium, which we
call calamine, an impure ore of zinc. In this country brass is
sometimes made by mixing the impure ore of zinc with pure
copper and charcoal. Bell metal contains tin, and zinc mixed
with copper. Gun metal is called brass, but Wass' is too brittle
for such a purpose. It is an admixture of copper and tin in the
proportion of 9 parts of copper to 1 of tin. Copper utensils,
for•doinestic parposps, are dangerous, when acids are introduced
nto them, to prevent this, it is usual to tiu the interior surface
Of such vessels. The operation, of tinning is very simple.
The copper is rubbed' over with a solution of muriate am-.
znonia, (sal-ammoniac) after which it is. heated and rubbed over
with pitch. The utensil is then brought to the temperature of
melting tin, and rubbed over with block tin, when the tin ad-
heres to the copper, and the pitch renders it of an uniform thick-
ness. Now, although this coating of tin is exceedingly super-
ficial, it is sufficient to prevent any action of the acid upon the
copper.
. _

Lead, as well as copper; is found in most parts of the world.
Lead and copper are found mineraiivd with almost every other
mineralizing agent. Lead has seldom or ever been found in its
native metallic state. It is generally found as a suiphuret of
lead—a compound, as its name impaes, of lead and sulphur.
Now we have perh ips as valuable lead mines in Great Britain
as in any part of the world, and the mode of reducing the mineral
in this country is equal to any known. The ore is reduced to
the state of powder, and washed in- the usual manner, and then
roasted, to drive 'Off fhe arsenic and the Sulphur. Lime and
carbonaceous matter are contained in the furnace with the sul-
phuret of lead, and assist its fusion. The sulphur unites with
the lime, forming sulphate of lime, and the oxygen with the
carbon, forming carbonic acid; whilst the pure metal sinks to
the bottom, and is run into moulds in the form of pigs and thick
sheets. Lead is one of the softest of all metals; it is softerthan
all of them, with the exception of the newly.aiscovered bases to
the alkalies and earths. It-is a very malleable, but not a very
ductile one. In this it differs from copper, which is very ductile
as welt as malleable. It melts attbe temperature 0f590 degrees.
lt,has much metallic lustre, but this is soon lost by its conabin-
iag with the sulphuretted hydrogen of the atmosphere. It is
said that in England alone we reduce about 48,000 tons of lead.
annually. By exposure to heat, two oxides of lead may be
formed. Some persons suppose that we have three oxides. By
exposing melted lead to the action of the atmosphere it 'will be
covered almost immediately with a blue film. '[his blue filtn,
if. iaked off; forms the protoxide or massicot of commerce. This
is made in.largequantities, in the reduction of the galena ores,
when it is wished to extract the silver front the lead. In ,{his case
the silver is extracted by heating it inteusely, until all the lead is
converted into what is'called -dross, or the protoxide. In this
way, the operation is continued of raking off the oxidatirin until
we have nothing left but a button of silver. This mode of re-
ducing lead is mentioned by Jeremiah and Ezekiel. In one
part of Ezekiel he says " The House of Israel is to me become
dross; for they are brass, and tin, and lead, in the midst of the
furnace; they are even the dross of silver." Jeremiah says.,
"'The bellows are burnt, the lead-is consumed of the fire, the
founder melteth in vain, for the wicked are tint plucked-away.
Reprobate silver shall men call them, becatise the Lord has
rejected them." Now these minute descriptions of the process
indicate very clearly that they adopted the same process of se-
parating the silver trim tha lead that we now practise. If we
expose the protoxide to heat- for 48 hours - longer, we get the
red lead of commerce. According to Some his not a peroxide
of lead, but merely a mixture of theprotoxide and per aide of
lead, for if we dissolve souse of it in nitric acid, we•shall haYe a
blackish substance, which is protoxide of lead. - We have prot-
oxide of lead in a state of solution,-and peroxide of lead precipi-
tates. According to some chemists, this is a sesquioxide of lead,
and, according to others,,merely A mixture of the protoxide and
peroxide of-lead.- Now we may easily separate the oxygen from
the protoxide of lead, or from the peroxide, by heating it with a
carbonacemis substance to combine with' the oxygen. If we
heat a. little of either, on a piece of charcoal, by means of the
blowpipe, we may reduce them to the -metallic state again.
Nitric acid will dissolve lead very readily; it mixed with four
times its weight or. water. We then have the nitrate of lead,
but it is less commonly employed than theacetate of lead (sugar
of lead.) 'The acetate of lead is made by diSsolving lead in
acetic or pyroligneoua- acid. It is very extensively used in the
dyeiug and colouring processes. We have. 'a sub-acetate of
lead, called Gourd's Extract, which is emplOyed in Medicine.
Sugar- of lead fs used as a styptic, and applied externally to
weunds, bruises, Stc. It was formerly supposed that sugar of
lead was a deadly poison ; and, as we know that wine-mereliants.
Use it very often in the adulteration of wines,,it became ari tin-'
portant question to ascertain all•the,-facts :connected' with its
poisonous- attributes. According to some recent experiments,
it does not appearto be poisonousif not taken into the stomach
as a carbonate, or with something which will make a carbonate
of lead.- But as, when a solution of sugar of lead is allowed to
stand exposed to the atmosphere, a film of carbonate of lead will
be formed on its surface, so in like manner the carbonic acrid of
the stomach will convert a portion of it into a carbonate of lead,
which is a deadly poison. If, however, the acetate of lead be
administeied to animals combined with vinegar, it may he taken
with' impunity. The animals appear to be little or not at all
affected by it. The chlorides of lead are of very little use, the
patent yellow pigment being now superseded-by chrome yellow.
Sulphuric acid acts very feebly on lead; but when concentrated
and in a boiling state, it will rapidly act upon it; yet it appears
a little singular that this acid will abstract lead from any of its
combinations. If we add a solution oflead to water, it will be-
come rather turbid; but if we add sulphuric acid, a dense white
precipitate of sulphate of lead will be formed. As Collateral tests
of the presence of lead, hydriodate of potass, chromate of pot-
ass, and sulphuretted kydrogen are frequently used. The two
former give precipitates .of a yellow colour, and tile lattir of a
black. Indeed, so delicate a test is suipkureited hydrogen, that
if a piece of paper be dipped into a solution of lead, and exposed
I to the fumes of the sulphuretted hydrogen, the paper will be
turned to a deep black colour. it has been used as a sympa-
thetic ink for this reason. T
here is only one objection to its
use—the intolerable smell of sulphuretted hydiogen. We may
also precipitate lead by means a. a more oxydable metal;' thus,
if a piece of zinc he suspended in a strong solution of lead, what.
is called a zinc tree will he formed, which in reality is nothing
more than the precipitatien of the lead 'by the zinc. In order
to give the tree a good appearance, the solution .of lead Should
be filtered before the zinc is introduced. The usgs of metallic lead
are too well known to require enumeration. It was used by the
Romans in the state of sheets to sheathe the bottom 4 of their
ships. Sir Humphrey Davy introduced some nxidable metal
for the purpose of protecting the copper with which we now
sheathe our ships against the action of sea water. The cop-
per was protected, but the ship came home very foul in conse-
quence of the barnacles and sea-weed which attached to its
bottom, by which the sailing of the vessel was much retarded.
It is found, however, that, it the copper be partially protected,
this effect of the adherence of the barnacles and sea-weed will
not. take place. Indeed an alloy of copper and zinc has been
made for this purpose. Sheets of lead are manufactured by pth-
ting thick plates,of lead between powerful toilers. The art of
rolling pipes has been much improved of late years. Formerly
all pipes were soldered up ; subsequently the lead was cast into
a larger pipe, three feet long.-and drawn out into finer pipes.
The melted lead is now forced through a hole provided with a
sort of triblef into a pipe of any required length; and no further
operation is necessary. We now find that the lead pipe coated
with finis exceedingly valuable, and it is now beginning to be
extensively employed, notwithstanding the prejudice of the
plumbers against it on account of its durability.. ,
Mr. Hemming then concluded by thanking the audience for
the patience and attention with which they had heard him. He
feared that his course had not been so interesting as a course
on elementary chemistry might have been,
In terminating this course of delightful lectures, the, reports
of whirl] our readers will have read with pleasure. not Withstan-
ding the absence of the interesting experintents with which they -
.were illustiated by the talented lecturer, we think it an appro-
priate occasion to recommend to mil of our operative friends
as may be desirous of following up, the instructive science of
chemistry, an eaeellent little work upon the subject pulished
-by Dr. acid of Edinburgh, at. the low price of one shilling and
.
fourpence, which is one of the best elementary treatises we
have met . with. It nut} be had of Mr. Clay, chemist, Bold-
sti eet, as well as the various chemical materials required to per-
form an infinite number of cheinicel experiments.

-To B tt,i) PEi;f;J.k.:---e" French brandy, _dissolved with sul-
phate7iifigipPer:" slys a'.New York paler. " applied once a day
will make your hail grow." To this a Philadelphia paper adds,
" and if the hair should grow too abundantly, take a quart of.
French brandy a day, with a little sugar and nutmeg, audit will
come off again. Thus. brandy for your baldness and brandy
for abundant hair."-.---Americaa paper. •
The assertion of Sir Humphrey Davy that no species of plan t
will vegetate downwards, has lately been contradicted by -an ex-
periment made by Messrs. LoCkl;trt and Co., florists, Cheap-
sick, in a Narcissus, the bulb of which is placed in a large glass
vase filled With water. 'lie Narcissus is' now on the point of
coining into flower downwards, a large pod of bloom and seve-
ral long leaves being already visible in the water.

DISCOVERY OF .AN ISLAND.—The Geographical. Society has
received the following communication from Captain Derienrs,
concerning the discovery of an island :--7" December
.27, 1835,
having .entered into the dangerous clus.ter of the Society isle ,
observed the isle of Gambier, and being on my way to flood's
isle, at ten o'clock, a.m., when still on the south of that isle,
and making way towards the west, the sailor on the look-out
cried 'Land on. the larboard bJw!' at which I was astonished,
as none of
.my maps noted any land in that direction, at least.
at that distance. I steered towards it, and at two o'clock was
within two miles. !I-:observed that it was a low•island, about
twelve miles in extent, rather woody in the middle, with its
south and north-west extremities bordered with cocoa trees. I
was not able to discover any traces of inhabitants, or any vessels
on its coasts. Its position is .21. deg. 39. min. south lalitude.at
its most northern point; the longitude of the middle 138 deg.
Umin. west;. we do not think it-bears any name."—Phare.de
Dieppe. . . •
LERCHES.—A French physician prescribed the application.of
fetches to a patient, and soon afterwards visited the sick.mahrs
domicile, when the following colloqu,;• took-place with hiS•wife
'" Well, my good woman, how is yruir husband to-day ?" " Bet-
ter, no doubt." "I thought so," continued M. le Docieur ,
".the leeches have cured him! Wouderfril effect they have!
You got the leeches af course." " ves, Monsieur le Doc-
tear, they did him a deal of good, thoiigh he could not take
them all." "Take them all. • Why. my good woman,. bow did
von apply them ?" "Oh. I managed •llieely," said the wife,
goiTe contented with herself. 6- For variety's sake, I
boiled one-halt, and wade a fry of the other. The first he got
down very welt, but the s,roncrmade hint very sick,. .But what
lie took WilS (pits euolot,h," Conri,med She. Wremg some horror
in the doctor's countenance, " for be was better the next dav,
and to-day he is quite '' tlh ! " said the doctor.' with
a swpiblitslti:kil that s
sta,.icient:4.lkurdhity
Tho wowsu That she v, so next lime; :Jl4l ao,,ht-
leSs, if ever fate thi•oss a score of unfortun:“e Ireyhe into her
power again, she will make a i:oultice of them.