IMPROVEMENTS IN THE APPLICATION OF CHEMICAL AGENTS TO NATURAL OR ARTIFICIAL STONES AND TO STUCCOES IN ORDER TO DIMINISH THEIR POROSITY INCREASE THEIR RESISTANCE TO EXTERNAL INFLUENCES communicated to him from ab by Messieurs
Year: 1883

page_text: ETTERS PATENT to William Spence of 8 Quality Court Chancery Lane
in the County of Middlesex Patent Agent for an Invention of "IMPROVEMENTS
IN THE APPLICATION OF CHEMICAL AGENTS TO NATURAL OR ARTIFICIAL
STONES AND TO STUCCOES IN ORDER TO DIMINISH THEIR POROSITY
INCREASE THEIR RESISTANCE TO EXTERNAL INFLUENCES communicated to
him from abroad by Messieurs Faure and Kessler of Clermont-Ferrand in the
Republic of France
"
AND
PROVISIONAL SPECIFICATION left by the said William Spence at the
Office of the Commissioners of Patents on the 17th October 1883.
WILLIAM SPENCE of 8 Quality Court, Chancery Lane in the County of Middlesex
Patent Agent
"IMPROVEMENTS IN THE APPLICATION OF CHEMICAL AGENTS TO
NATURAL OR ARTIFICIAL STONES AND TO STUCCOES, IN ORDER TO DIMINISH THEIR
POROSITY AND INCREASE THEIR RESISTANCE TO EXTERNAL INFLUENCES (a com-
munication to me from abroad by Messieurs Faure and Kessler of Clermont-Ferrand
in the Republic of France)
"
The processes and agents included in the present invention have a certain
analogy with silicatisation by means of alkaline silicates and with these silicates.
The only residues left in the stone are insoluble volatile products.
Fluosilicates are principally employed, and which are prepared either in solution
or a solid state.
For white stones are employed:
The fluorhydrate and the fluosilicate of ammonia,
The fluorhydrate and the fluosilicate of magnesia,
The fluorhydrate and the fluosilicate of alumina.

page_text: "
The colourations can be produced in two operations; as for instance by treating
with fluosilicates of lead or mercury and afterwards with an iodide or chromate.
The fluorides leave in the chalky matters only fluor spa and their oxides. The
fluosilicates leave silicates besides. The fluorhydrate of ammonia leaves only
fluoride of calcium, for it is freed from the carbonate of ammonia.
Thus may be produced the impermeability or hardening or the colouring of
stones, stuccoes or moulded plasters. A stucco or a moulded plaster made with
hydraulic or ordinary lime, cement or plaster mixed with lime or even with
clay, will become hard and ornamental after its impregnation. Clay and china
becoming hard like stone when made into a paste with fluosilicic acid (hydrofluo-
silicic) of 40° Beaumé will serve for lutings or mastics in the arts, and especially
with acid substances. This paste can also be moulded, turned like clay and admit
of the formation of vases or utensils and other articles without baking. Besides the
derivatives of fluorine just named, there are employed certain insoluble phosphates
by themselves, after having dissolved them in acids, which become themselves
insoluble in contact with stones.
Such are the earthy or metallic phosphates dissolved in phosphoric acid, in
bydrofluosilicic acid, in fluorhydric acid, even in sulphuric acid; such is the
phosphate of lime dissolved in phosphoric acid (superphosphate).
The phosphate of alumina dissolved in sulphuric acid or hydrofluosilicic acid.
Also the soluble aluminate of Baryta and the sulphates of insoluble oxides employed
as hereafter stated.
The impregnation of these various products can take place in a more or less
loosely combined state, in one or several operations, with or without desiccation.
It can also either precede or follow that of different known agents or those
named above.
Thus after having hardened the substance to an alkaline silicate, if it be caused
to absorb fluosilicate or fluoride of aluminium, the soda or the potash is thereby
rendered completely insoluble, in the state of or similar to cryolite, and nothing
soluble remains in the substance or material.
In like manner by treating with aluminate of baryta after sulphate of alumina
or sulphate of magnesia, the residue is left absolutely insoluble: sulphate of baryta,
alumina, magnesia, and the aluminate in excess yields a very hard carbonate of
baryta.
Lastly may be mentioned:
The alkaline aluminates and the alkaline silicates succeeding the former, whether
in inverted order or mixed together.
It is known that when a similar mixture is saturated with carbonic acid, there
is produced an alkaline silico-aluminate in which the alkaline base is become
insoluble. If the acid employed is found to be hydrofluosilicic acid or fluorhydric
acid combined with alumina, it forms an insoluble alkaline silico-aluminate, and a
cryolite" equally insoluble. The excess of fluoride or of fluosilicate being trans-
formed by the calcareous matters into products also insoluble, the same end is
attained. The reactions may vary between the before named, agents, and give
in a number of cases products quite insoluble, and it is not necessary to cite
them all.
It will be understood that when it is the impermeability that is aimed at, and a
certain polish or enamel, there may be added to these agents an encaustic or a
substance whether oily or damp-excluding like wax, stearine, paraffin dry melted
or dissolved.
It matters little that other bodies or substances are afterwards added, since it is
the application of the above named impregnating agents to the bodies or substances
indicated or their analogues which constitutes essentially the invention.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Spence in the Patent Office on the 16th April 1884.
WILLIAM SPENCE of 8 Quality Court Chancery Lane in the County of Middlesex
Patent Agent "IMPROVEMENTS IN THE APPLICATION OF CHEMICAL AGENTS TO
NATURAL OR ARTIFICIAL STONES AND TO STUCCOES IN ORDER TO DIMINISH THEIR
POROSITY AND INCREASE THEIR RESISTANCE TO EXTERNAL INFLUENCES (a com-
munication to me from abroad by Messieurs Faure and Kessler of Clermont Ferrand
in the Republic of France'
"
"
The processes and agents included in the present Invention have a certain
analogy with silicatisation by means of alkaline silicates and with these silicates
The only residues left in the Stone are insoluble volatile products.
Fluosilicates are principally employed and which are prepared either in solution
or in a solid state.
For white Stones are employed.
The fluorhydrate and the fluosilicate of ammonia
The fluorhydrate and the fluosilicate of magnesia
The fluorhydrate and the fluosilicate of alumina
The fluorhydrate and the fluosilicate of zinc
The fluosilicate of lead.
In colored stones or stuccoes or for coloring other stuccoes.
The fluosilicates of iron
The fluosilicates of manganese.
The fluoride and the fluosilicate of chromium cobalt nickel or other metals.
The colorations can be produced in two operations as for instance by treating
with fluosilicates of lead or mercury and afterwards with an iodide or chromate.
The fluorides leave in the chalky matters only fluor spa and their oxides The
fluosilicates leave silicates besides The fluorhydrate of ammonia leaves only fluoride
of calcium for it is freed from the carbonate of ammonia.
Thus may be produced the impermeability or hardening or the colouring of
stones stuccoes or moulded plasters A stucco or a moulded plaster made with
hydraulic or ordinary lime cement or plaster mixed with lime or even with Clay
will become hard and ornamental after its impregnation Clay and China Clay
becoming hard like stone when made into a paste with fluosilicic acid (hydrofluo-
silicic) of forty Beaumé will serve for lutings or mastics in the arts and especially
with acid substances This paste can also be moulded turned like clay and admits of
the formation of Vases or Utensils and other articles without baking Besides the
derivatives of fluorine just named there are employed certain insoluble phosphates
by themselves after having dissolved them in acids which become themselves
nsoluble in contact with stones.
Such are the earthy or metallic phosphates dissolved in phosphoric acid in
ydrofluosilicic acid in fluorhydric acid even in sulphuric acid.
Such is the phosphate of lime dissolved in phosphoric acid (superphosphate)
The phosphate of alumina dissolved in sulphuric acid or hydrofluosilicic acid.
Also the soluble aluminate of Baryta and the sulphates of insoluble oxides
employed as hereafter stated.
The impregnation of these various products can take place in a more or less
oosely combined state in one or several operations with or without desiccation.
It can also either precede or follow that of different known agents or those
named above.
Thus after having hardened the substance to an alkaline silicate if it be caused
o absorb fluosilicate or fluoride of aluminium the soda or the potash is thereby

page_text: rendered completely insoluble in the state of or similar to cryolite and nothing
soluble remains in the substance or material.
In like manner by treating with aluminate of baryta after sulphate of alumina
or sulphate of magnesia the residue is left absolutely insoluble sulphate of baryta
alumina magnesia and the aluminate in excess yields a very hard carbonate of
baryta.
Lastly may be mentioned.
The alkaline aluminates and the alkaline silicates succeeding the former whether
in inverted order or mixed together It is known that when a similar mixture is
saturated with carbonic acid there is produced an alkaline silico-aluminate in which
the alkaline base is become insoluble If the acid employed is found to be hydrofluo-
silicic acid or fluorhydric acid combined with alumina it forms an insoluble alkaline
silicoaluminute and a "cryolite" equally insoluble The excess of fluoride or of
fluosilicate being transformed by the calcareous matters into products also insoluble
the same end is attained The re-actions may vary between the before named
agents and give in a number of cases products quite insoluble and it is not necessary
to cite them all.
It will be understood that when it is the impermeability that is aimed at and
a certain polish or enamel there may be added to these agents an encaustic or a
substance whether oily or damp-excluding like wax stearine paraffin dry melted or
dissolved.
It matters little that other bodies or substances are afterwards added since it is
the application of the above named impregnating agents to the bodies or substances
indicated or their analogues which constitutes essentially the Invention.
Having thus described the nature of the said Invention and in what manner the
same is to be performed (communicated to me from abroad as aforesaid) I hereby
declare that what I claim as of the said Invention is
The application of the processes and the chemical agents to natural or artificial
stones and stuccoes for the purpose of diminishing their porosity and increasing
their resistance to external influences substantially as hereinbefore described.
In witness whereof I the said William Spence have hereunto set my hand and
seal this sixteenth day of April in the year of our Lord One thousand eight
hundred and eighty four.
WILLIAM SPENCE 1101