The Liverpool Standard and General Commercial Advertiser.
Liverpool, Merseyside, England, 1838-10-12 00:00:00

American forests we should be unable to procure our pc;tash
from vegetable sources, we might be able by the decomposition
of felspar to procure a supply of potash to last us for a long
time. Felspar consists of silica united to alumina and pot-
ash. In fact we may divide the silica into two proportions,
and then in the first place we shall have one portion united
with the potash, and in the second place another portion
united to the alumina. Now the combination of silica with
potash is a salt, and the combination of silica with alumina is
likewise a salt, therefore this felspar is a double salt of which
there exist vast numbers in chemistry, some of which are of
great importance. Alum is an artificial product which ca❑
scarcely be said to exist naturally, bUt which is'of great impor-
tance in the arts. It is a combination of sulphuric acid with alu-
mina, sodium, and water. The sulphuric acid is thus divided
into two portions, now leaving out the water, which by simply
drying the alum we may get rid ef, we shall see that alum
very much resembles the felspar which we can scarcely form
artificially, but which abounds in nature. Now all glass and
porcelain are double salts resembling felspar in a very great
degree. Our object its the manufacture of porcelain is to
bring silica and potash together so that they may resemble
the porcelain we wish to obtain. It is our object to get glass
of a certain degree of fusibility, and we therefore unite them
in certain proportions so that the resulting salt may be manu-
factured of whatever purity we may desire. Porcelain, on
the contrary, it is our object to form in such a way that it
shall be very difficult to melt, and the easy fusibility which
is so much to be desired in glass is a great objection in
porcelain. For these processes there are different proportions
employd. The silicates of the alkalies are far more
easily melted than the silicates of the earths. Silicate of
potash makes a pure glass of an intermediate degree of fusi-
bility, but in practice it is necessary to have glass of different
degrees of fusibility. and to effect this different substances
are used. Lead is added to render it more fusible, anti lime
to decrease its fusibility. We have, therefore, three varieties
of glass : flint glass, a double silicate of potash or soda and
lead, and the different varieties of crown glass, which have
introduced into them a greater or less degree of fusibility.
In the manufacture of table glass there are threelngredients:

the fine sand sometimes procured from Lyme Regis, some-
times from South America and other distant places, as it
must be of great purity; then we have the alkali, chiefly
soda, on account of its cheapness and greater powers of sa-
turation; and, in addition to these, a great quantity of red
lead. In fact, in making use of red lead, there are two im-
portant objects gained: the first is, the manufacturer makes
his glass more fusible, and saves his coals; in the next place,
the lead being a heavy ingredient, he increases the value of
his glass by being enabled to charge more for it. An article
made of glass containing lead weighs more than if no lead
had been employed; and as it is paid for by weight. the pro-
fit of the manufacturer is greater. But in addition to this,
the red lead gives the glass a degree of lustre which enhances
its appearance; therefore, as an article of luxury, it is in-
creased in value. There are limits to this addition of lead;
as it is liable to be acted upon by acids, although combined
with the silicate of soda: indeed, drinking-glasses are some-
times acted upon by the liquids they may contain, and it is
well known that the cylinders of some electrical machines
can scarcely be kept dry, owing to the presence of too great
a quantity of lead. The manufacture of plate and crown
glass differs from that of flint glass, because it is necessary
to make the former much harder. In consequence of this,
cheaper materials are used: lead is left out, and the soda or

potash is replaced to a'great extent by lime. The presence
of lead in glass may he readily ascertained by pounding the
glass, mixing it with charcoal, anti putting it into a crucible;
when exposed to heat the lead wi►l melt, and collect at the
bottom of the crucible. There is made at Prague, in Bo-
hemia, an article which is beautiful as an article of luxury,
and is very useful in a scientific point of view. It is a pure
silicate of soda, and requires an intense heat to melt it. With
it we can operate with ease in chemistry, as it is neither
liable to melt nor to crack with sudden variations of heat and

„S fpong Enttlliqentr.

TUESDAX, SEPTEMBER 9.
ARRlVED.—Wilhelmina Henrietta, Kruse, & Black-eyed Susan,
Thomson, from Danzig—Dorette, Voss, from Rostock—Triton,
Bengston, from Stockholm—Fame, Pentecost, from St. Petersburg
—and George, -, from Alexandria, Egypt.
SAlLED.—Boddingtons, Moss, for Africa—Mary Brade, Jones
for Barbadoes, So.—and Pocahontas, West, for Philadelphia.

William & Thomas, Ley, from Aberavon; at this port, and will
sail for Barra in a few days to load iron ore for Aheravon.
Julie. Kunon, from Danzig, at this port. On 28th Sept. ran on,
the rocks near Roualdshay, but got off without material damage,
after discharging a considerable part of the cargo
Cybele, Armstrong, from Bahia, at Pernambuco, and sailed 12th
Aug. for Maceio
Bed Rover, hence at Alexandria
Charles Henry, Smith. hence at Smyrna
Postboy, Perriam, and Redbreast, Millard, from Constantinople,
at Smyrna
Lynx, Forsyth, sailed from Smyrna 12th Sept. ; Pet, Stone, 13th,
both for Liverpool. and Prowler, M•Dowell, 19th for Dublin
Levant Packet, Tray, hence at Venice
Harriet, Beniest, hence at Adtwerp
Egidius, Dnyts, hence at Ostend
Page, Griffiths, from Danzig for this port, at Milford, short of
provisions
Fanny, Sloan, hence for Quebec, off St. Paul's 7th Sept.
Eliza Kincaid, --, from St. Petersburg for this port, at Pent-
land Frith 29th Sept.
Union, Weinhold, from Memel, off this port, is aground in the
New Channel
Lady Mary Fox, Sowerhy, sailed from Belfast for Demerara 2nd
instant -
The head-hoard of a large vessel, with " Aberfoir; in yellow
letters, was picked up 26th ult. off Lundy Island

WIND AT HOLYHEAD N.W.-LIGHT BREEZE

An inward-bound ship aground in the New Channel, a steamer
near her, at 8 a.m.
Off Holyhead. at 7 a.m. (not quite sure of the Ist flag,' No. 1792,
James Hunt, 8.8.
Off Point Lynas, at 7 a.m. No. 1048, Equator, A.S.
Off Holyhead, at 9 a.m. N0..382, Superior, 8.8.
Off Point Lynas, at 9 30 a.m. (has a pilot,) No. 1792, J ames Hunt,
8.8. from Antwerp
Off Holyhead, at 10 30 a.m. No. 826, Oxford, A.S. for New York
ofr Holyhead, at 11 30 a.m. No. 1048, Equator, A.S. for New
Orleans. and No. 207, Alice, B.S. for Barbadoes
The ship that was ashore, has got off, and is inward-bound, in
tow by a steamer, at 12 tIO p.m.
Off Holyhead, at 12 at noon, No. 1291, Charlotte, B.Bk. from
Quebec.
Off Holyhead, at 12 30 p.m. No. 1644, Eclipse, (steamer.)
Off OE Point Lynas, at 12 30, No. 382, Superior, 8.8. (has a
pilot.)

WEDNESDAY, OCTOBER 10.—Wind N.W. light.
ARRlVED.—Charl9tte, Fisher, fin Quebec—Commerce, Prowse,
8: Olive Branch, Prink, from Gijon—ltossina, Verrier, from Boor-
deaux—Ann Charlotte, Jacobson, from Grenville—Eliza Kincaid,
Brown, from St. Petersburgh—Graff Gueisenan Lutke. from Dan-
zig—Malaga, Cancano, from Hambut gh—Sunerior, Walker, from
Amsterdam—Eugene, Zerran, and James Hunt, M`Donald, from
Antwerp—lndustrie, Sohn, from Ostend—and Eclipse, M'Ritchie,
from Pillan.
It, indeer, Head, from Belfast, at this port, in 13 hours
Porter, Porter, and Dorset, Bishop, hence at Madeira, and both
sailed 13th ult. for South Australia _ _

Little Catherine, Williams, hence at ditto, and sailed 18th ult.
for Demerara

Yarmouth, Holt, hence at Beirout
Orfeur, from Malta, at Corfu

Triton, Seorgie, hence at Malta
Levant. Cundy, from Castelvetrano, at ditto
Ruth, Corrigall, from Kerteb, at ditto
Robert Seprileld, Clough, from Llanelly, at ditto
Nora Creina, Artis, from Zante, at Patras
Saucy Jack. Farrant, from ditto at ditto, and sailed 3rd ult. for
London

Beetles, Manthorpe, hence at Trieste
Rob Roy, Inglis. from Alexandria, at ditto
Corsair, Greig, from Rio Janeiro, at ditto
Arrow, Harris, and Premier, Newman, hence as Gibraltar
Wm. Harris, Lely, from Gibraltar, at Malaga
George Canning, Deynon, from Denia, at ditto
Laura Ann, Casely, hence at Lisbon
Oporto. Smith, hence at Oporto 2nd instant
Emma Graham, Ferguson, hence at ditto
Norfolk, Cuel ; Victoria, Burns ; Anna Elizabeth, Poulsen ;
Sarah, Watford, and Pericles, Storey, hence at Elsinore
The Camoens, Barnes, for this port, and Oporto, Woollaghan,
for Dublin, sailed from Oporto 27th ult.
Victory, Jarvis, sailed from Lisbon for this port 28th ult.
Gilbert Henderson, Twedie, sailed from London for Batavia 9th
instant
Janet, Wingate, from Rio Janeiro. at the Clyde
Industry, Hester, from Para, at Fowey, anti sailed for Swansea
Arcadia, Barker from Fernando Po for London, put into Ter-
ceira 15th ult. with 10 feet water in the hold, and totally destitute
of provisions, having been out 70 days
Susannah. Watson, from St. Petersburgh at Newry, ran on a reef
off the north end of Gothland, during thick weather, but got off
after throwing overboard 12 casks of tallow
. Thomas Bold, Croughan, hence for. Rio Janeiro, was spoken 23rd
Aug. in lat. 12 37 N, long. 25 W
Bland, Callan, hence for Calcutta, was spoken 24th Sept. in lat.
48 11,1ong. 8

THURSDAY. OCTOBER 11.—Wind W.
ARRlVED.—Argentina, Kelso. from Monte Video—Banffshire,
—, from Quebec' sailed sth Sept.—Charite, Falange. from St.
Maio—Crescent, —, from Charente—Page, Griffiths, from
Danzig—Cornelia, —, from Hamburgh—Concordia, Eddes,
from Dordt—Apollo. --, from Jersey—Waterlillv, Campbell,
from Newfoundland ; sailed 19th Sept.- Vrow 'Lelia,
from Embden--Welgina, Griven. from Rotterdam—Nyverheid,
Lievens, from Antwerp—Victoria, —. from Jersey—Wilhel-
mine, from Riga—Pauline, —, from Ostend—Sisters, Sutton,
from Danzig and Yarmouth—Weetgean. Greven. from Rotterdam
—Frawle, Nieman, from Embden—Pifferfisma, Batgan, from
Dordt—Cmur de Lion, from Quebec—and Marys, from the Baltic
and Hull.

ALSO ARRIVED.—Maria Catharina, from Cork—Endeavour,
—, from Drogheda—Neptune, Jenkins. and Selina, Billing,
from Charkstown—Lonisa, Sobey, from Penzance—Favourite,
Jones, and Earl Selkirk. Halliday. iron, Cardiff—Pilot. Chambers,
from Dundee—Ann St Kate, from Wexford—Orion, Smith, from
Wells.