IM- PROVED MEANS FOR THE PROTECTION AND PRESERVATION OF LEAD SURFACES EXPOSED TO THE ACTION OF WATER, AND FOR THE PROTECTION OF SUCH SURFACES FROM DECOMPOSITION BY ATMOSPHERIC ACTION
Year: 1862

page_text: PROVISIONAL SPECIFICATION left by Fédor de Wyldé at the Office of
the Commissioners of Patents, with his Petition, on the 17th December
1862. A communication from abroad by Professor Dr. Henry Schwarz,
of Breslau, in the Kingdom of Prussia.
I, FEDOR DE WYLDE, of Great College Street, Camden Town, in the County
of Middlesex, do hereby declare the nature of the said Invention for "IM-
PROVED MEANS FOR THE PROTECTION AND PRESERVATION OF LEAD SURFACES EXPOSED
TO THE ACTION OF WATER, AND FOR THE PROTECTION OF SUCH SURFACES FROM
DECOMPOSITION BY ATMOSPHERIC ACTION," to be as follows:-
This Invention consists in rendering lead surfaces insoluble in water by
transforming the metallic lead into a sulphuret of that metal, thus preserving.
from corrosion pipes and cisterns exposed to the action of water, and roofs or
other surfaces exposed to the alternate action of water and atmospheric air,"
and also preserving water in contact with such surfaces from contamination.
For the purposes of my Invention I take a solution of any metal in com-
bination with sulphur soluble in water, that is to say, the soluble sulphides or
sulphurets (especially those which have an excess of sulphur), such as the
sulphides of ammonium, potassium, sodium, lithium, barium, strontium, mag-
nesium, calcium, or the hyposulphites of these bases, and other metals,
aluminium, zinc, iron, or other suitable metals; liver of sulphur or the
reduced sulphates may also be used. By preference I take a solution of
caustic potash or soda, and boil with an excess of sulphur so long as any
sulphur is dissolved.

page_text: The manner in which I apply my Invention is as follows:-I take a
solution containing from two to five per cent. of a solid sulphuret, and having
heated this solution in a boiler or other vessel to one hundred degrees cen-
trigade or 212° of Fahrenheit, I immerse therein the articles to be operated
upon. When the interior of pipes is to be treated, the solution is made to
circulate through them by means of a pump, as shewn at A, Fig. 1, which
may be placed in the boiler B containing the solution. The solution being
pumped into one end of the pipe or pipes C, and having passed through them
is allowed to flow from the other end D into the vessel or boiler B, from
which it was drawn; the circulation of the solution through the pipes is thus
kept up until the operation is complete. Other means may be adopted to cause
the solution to circulate through the pipes.
An apparatus for such purpose is also shewn at Fig. 2 in the accompanying
Drawings, it consists of two portable boilers and furnaces A and B attached
to the ends of an oscillating beam C, which is supported upon a standard D.
The one boiler B being elevated, the solution contained therein is allowed to
pass (by means of the tap E and a piece of vulcanized india-rubber hose F)
through the lead pipes (and by a similar piece of vulcanized india-rubber
hose G and tap H) into the boiler A at the lower end of the beam, and when
the solution has passed into the lower boiler, the beam being reversed, this
boiler takes the higher position, and the solution again circulates through the
pipes, returning to the boiler B, which will then be on the lower level in a
similar manner to that before described.
The reversal of the relative positions of the two boilers may be effected as
often as may be found necessary for the sufficient circulation of the solution
through the lead pipes. Any number of lengths may be operated upon at one
time by uniting them with a tube of vulcanized india-rubber. The solution
may be applied to cisterns or other lead surfaces by brushing or similar
suitable means.
The solution so applied transforms the metallic surface of the lead into a
sulphuret or sulphide of lead, and any soluble product remaining may easily
be removed by rinsing the pipes or other articles with hot water, which may
be provided in a boiler, such as shown at Fig. 3.
Lastly, where required I make use of a current of air or other suitable
means for drying the surfaces that have been thus operated upon.
If in soldering or joining any such surfaces injury is done to the coating
of sulphuret or sulphide of lead, I apply a weak solution of sulphide of
potassium.
The effect produced by my process is easily explained. Lead-glance or

page_text: sulphuret of lead is one of the most insoluble preparations known of that
metal, and one not subject to deterioration. Oxidation does but change it
into an equally insoluble oxysulphuret.
The most convincing proof of the perfectness of my Invention exists in the
well-established fact, that the water found in mines of galena, lead-glance, or
sulphuret of lead, is not contaminated with any of the soluble salts of that
metal.
Claim. I claim as my Invention the treatment of lead surfaces by the
solution in the manner and for the purposes herein-before described.