AN IMPROVED ANTI-CORROSIVE AND ANTI-FOULING COMPOSITION
Year: 1877

page_text: LETTERS PATENT to Peter Denniston and John McMillan, both of Glasgow,
in the County of Lanark, North Britain, for the Invention of "AN
IMPROVED ANTI-CORROSIVE AND ANTI-FOULING COMPOSITION."
Sealed the 11th January 1878, and dated the 25th October 1877.
PROVISIONAL SPECIFICATION left by the said Peter Denniston and John
MoMillan at the Office of the Commissioners of Patents on the 25th October
1877.
PETER DENNISTON and JOHN MCMILLAN, both of Glasgow, in the County of
Lanark, North Britain.. "AN IMPROVED ANTI-CORROSIVE AND ANTI-FOULING
COMPOSITION."
This Invention, which relates to an improved anti-corrosive and anti-fouling com-
position, has for its object to protect the bottoms of ships or other submerged bodies
or structures, both from corrosion as well as from fouling, by the growth thereon of
plants, weeds, or animal life.
'
The Invention consists of a new combination of substances which when commingled
together constitute what we prefer to call a "varnish paint," that is to say, a
compound which has the properties of both varnish and paint, and is at the same
time so elastic that it will not easily crack off the surfaces coated therewith.
The compound consists of rosin, sulphur, oxide of iron or oxide of lead, whiting,
turpentine or naptha, boiled oil, oxide of mercury.
In commingling these substances together so as to produce the compound, the
rosin and sulphur are liquefied by heat, and to these the oxide of iron or oxide of
lead and whiting are added. To this mixture of substances we then add turpentine
or naptha, and boiled oil. The foregoing substances when commingled together as
described, form when cold a viscous or semi-fluid mass, and to this the oxide of
mercury is added. To this preparation we sometimes add some insoluble soap for
the purpose of allowing any growth which may take place to exfoliate.
D
71

page_text: In applying the compound for coating the submerged portions of a ship, or other
bodies or structures, we make a solution of heated turpentine, sulphur, and rosin,
which we add to the compound herein-before described in order to reduce it to the
consistency of a paint, which we then apply by means of a brush to the surfaces to
be coated.
Proportions of the foregoing substances which are found to answer in practice
In applying the compound for coating the submerged portions of a ship, or other.
. bodies or structures, we make a solution of heated turpentine, sulphur, and rosin,
which we add to the compound herein-before described in order to reduce it to the
consistency of a paint, which we then apply by means of a brush to the surfaces to
be coated.
Proportions of the foregoing substances which are found to answer in practice
are,―
Rosin
Sulphur
40 parts by weight.
ور
" '
"
Oxide of lead
10
Oxide of iron
or
55
"
"
Whiting
30
"
>>
"
}
3 gallons.
* 1½
ور
Turpentine-
or
Naptha
Boiled oil
Oxide of mercury about 10% weight of the foregoing.compounds.
For the solution with which the foregoing substances are thinned for practical
application, we employ turpentine in the proportion of three gallons to 3/4 lb. of 2
sulphur and 1/2 lbs. of rosin.
0
When it is desired that the compound constituting this Invention should be of a
greenish colour, we substitute for the oxide of iron or oxide of lead and whiting,
yellow ochre and "celestial blue." We also use the arsenite of lead as a substitute
for the oxide of mercury; or it may be used together with the oxide of mercury in 2
the compound in the proportion of about 10% if used without oxide of mercury,
and in the proportion of 5% if used with the oxide of mercury.
It is to be understood however that the proportions in each case may be con- .
siderably varied.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter. Denniston and John McMillan in the Great Seal Patent Office
on the 24th April 1878.
PETER DENNISTON and JOHN MCMILLAN, both of Glasgow, in the County of
Lanark, North Britain. "AN IMPROVED ANTI-CORROSIVE AND ANTI-FOULING
COMPOSITION."
Our said Invention relates to an improved anti-corrosive and anti-fouling com-
position, and has for its object to protect iron and other surfaces or bodies from
corrosion and fouling, and more especially the bottoms of ships or other sub-
merged bodies or structures, by preventing the growth thereon of plants, weeds,
or animal living forms.
Our said Invention consists of a composition of substances, as herein-after
described, which when commingled together constitute what we prefer to call a
"varnish paint," that is to say, a compound which has the properties of both
varnish and paint, and is sufficiently elastic to prevent it from cracking and
peeling off from the surfaces upon which it is coated.
The ingredients of the said composition are:- Rosin, sulphur, oxide of iron or
oxide of lead, whiting, turpentine or naptha, boiled oil, and oxide of mercury.
In commingling these ingredients we liquify by heat and mix together the rosin
and sulphur. We then add to, and thoroughly mix with them, the oxide of iron (or
oxide of lead) and whiting. We next add the turpentine (or naptha) and boiled
oil. This compound when cold forms a viscous or semi-fluid mass, and to this the
oxide of mercury is added. In some cases we also add some insoluble soap for the
purpose of causing the exfoliation of any growth which may form upon the surface
coated.
The proportions of the foregoing ingredients which we have found to answer well
in practice are as follows, viz. :-

page_text: In this case we have found the following proportions of the ingredients to answer
well in practice, viz..―
Rosin
Sulphur
Celestial blue
48 parts by weight.
14
I
"
"
"
28
,,
"
""
Yellow ochre
20
"
"
"
Turpentine or naptha
25
=
"
"
"
Boiled oil
13
"
"
Oxide of mercury
14
"
"
"
Insoluble soap may likewise be added to this composition, as explained with
regard to that first described.
In place of or in addition to the oxide of mercury, herein-before mentioned, we
may use arseniate of lead, which should be carefully prepared and thoroughly dried.
We prefer to prepare it by making a saturated warm solution of basic acetate of
lead, and precipitating with a saturated solution of arsenious acid in aqueous
ammonia, the precipitate being collected and dried. When the said arseniate of lead
is used in substitution for the said oxide of mercury, we have found that a propor-
tion of the said arseniate equal to that of the said oxide of mercury, as given in the
preceding formula, to answer well. When the arseniate of lead is used in addition
to the oxide of mercury in making the compound, a proportion of about 5 per cent.
of the weight of the compounded ingredients will be found to answer well.
Having thus described the nature of our said Invention, and in what manner
the same may be carried into effect, we wish it to be understood that we do not
limit ourselves to the proportions of the ingredients of our improved composition as
herein-before stated, as the said proportions may be varied without departing from
the nature of our said Invention, but what we consider to be novel and original,
and therefore claim as the Invention secured to us by the herein-before in part
recited Letters Patent is, the improved composition herein-before described for
coating surfaces in order to protect them from corrosion and from fouling, the said
composition being formed by the admixture of rosin, sulphur, oxide of iron
or oxide of lead, or celestial blue, whiting or yellow ochre, turpentine or naptha,
boiled oil and oxide of mercury, with or without the addition of arseniate of lead, or
the substitution thereof for the oxide of mercury, and with or without the addition
of insoluble soap.
In witness whereof, I, the said Peter Denniston, have hereunto set my
hand and séal, this Twenty-third day of April, in the year of our Lord
One thousand eight hundred and seventy-eight.