A NEW OR IMPROVED MANUFACTURE OF OMPHALIC BLISTERS
Year: 1873

page_text: LETTERS PATENT to Duncan Mackay, Doctor of Medicine, of 1, Inglis
Street, Inverness, in the County of Inverness, for the Invention of
"
PROVISIONAL SPECIFICATION left by the said Duncan Mackay at the
Office of the Commissioners of Patents, with his Petition, on the
3rd September 1873.
I, DUNCAN MACKAY, Doctor of Medicine, of 1, Inglis Street,
Inverness, in the County of Inverness, do hereby declare the nature
of the said Invention for "A NEW OR IMPROVED MANUFACTURE OF OMPHALIC
BLISTERS," to be as follows:-
Blisters as hitherto manufactured are prepared by taking the proper
pharmaceutical preparation for blisters in a plastic state, and spreading
> the same in one mass over the surface of the material for the plaster,
thus producing a continuous vesicating appliance which is found in
many cases to be disadvantageous.

page_text: Now I manufacture blisters which I term omphalic from their
resemblance to the bosses of a shield by substantially the following
method, namely:-By means of a water bath I melt a small quantity
only (in comparison with the quantity commonly used for a blister), and
this I apply to the surface of the plaster, not by spreading it thick with
the thumb as at present, but by brushing it on gummed tissue paper
which is grease proof; then I apply a slicet of tissue paper, which
should be plain coloured, to the surface of the paper on which the
blistering preparation is spread, and iron them together so as to cause
them to adhere closely, and I cut out with a punch or similar instru-
ment small picces ready for usc. Each of these picces will consist of
the before-mentioned gummed tissue paper and plain tissue paper with
the blistering plaster between them. The gummed surface of these
picces is thus different and properly of a different colour to the other
surface, such gummed surface being made to adhere to a kind of
prepared paper; and the details of the mode which I prefer to use in
making the same is as follows:-I take tissue or any other paper, which
I coat with a preparation made by mixing one part turpentine with a
half pint (by measure) of castor oil. When the paper thus coated is
partially dry I press it between sheets of blotting paper, and I then coat
it with a varnish composed of rosin in methylated spirits of wine. When
the paper is dry after the varnish has been applied I coat it on both
sides with gum, and when dry I cut the paper thus prepared into picces,
say about half a foot square; I then take a piece of tin of the same size
as the paper, such tin being perforated with small holes in regular order.
The prepared paper being semi-transparent is then placed over the tin,
and the spots or pieces of blistering material (the gummed surface of
which having been previously damped) are placed over cach hole or
perforation in the tin on to the prepared paper to which they adhere,
and after the pieces or spots have all been put on the paper the whole
is inverted on dry blotting paper and pressed so as to make the gummed
surface of the spots adhere to the gummed surface of the paper. The
spotted sheets are then laid aside to dry, and when dry are ready for
usc. Plasters thus manufactured possess much superior qualities to
those manufactured by the ordinary methods, being more effective for
vesicating and yet being more bearable by the patient.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Duncan Mackay in the Great Scal Patent Office
on the 2nd March 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DUNCAN
MACKAY, Doctor of Medicine, of 1, Inglis Street, Inverness, in the
County of Inverness, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of September, in the year
of our Lord One thousand eight hundred and seventy-three, in the
thirty-seventh year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Duncan Mackay, Her special
licence that I, the said Duncan Mackay, my executors, administrators,
and assigns, or such others as I, the said Duncan Mackay, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the torm
therein expressed, should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "A NEW OR IMPROVED
MANUFACTURE OF OMPHALIC BLISTERS," upon the condition (amongst others)
that I, the said Duncan Mackay, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I; the said Duncan Mackay, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by the
following statement :-
Blistering plasters as hitherto manufactured are prepared by taking
the proper pharmaceutical preparation for blisters in a plastic state_and_
spreading the same in one mass over the surface of the material for the

page_text: mothod, namely:-By means of a water bath or other equivalent
appliance I soften a sufficient quantity of the blistering plaster and
apply it to the surface of gummed tissue paper, spreading it with a
spatula. I prefer that the gummed tissue paper should be prepared in
the manner herein-after described, then I apply a sheet of black tissuc
paper to the surface, and press it down so as to cause the two surfaces
to adhere closcly, and I cut out with a punch or similar instrument
small or large pieces ready for use; each of these picces will consist of
the before-mentioned gummed tissue paper and black tissue paper with
the blistering plaster between them.
The foregoing statements particularly describe and ascertain the
nature of the said Invention, and I will now further and particularly
describe and ascertain in what manner the same is to be performed, that
is to say: I make omphalic blisters by attaching two or more patches
or spots of blistering plaster or other blistering material to one piece of
prepared paper or other suitable substance; or by producing two or more
patches or spots of a blistering agent on a single piece of any material
for the purpose of making a corresponding number of vesicles or blisters
on the human skin.
The substance to which the patches or spots are usually attached is a
white tissue paper prepared in the following manner:-
The paper
having been cut into picces, say for instance six inches square, is brushed
over on both sides with a saturated solution of rosin in spirits of wine
and quickly dried over flame; it is then brushed on both sides with gum
arabic solution and hung up to dry. The prepared paper is laid on a a
piece of sheet zinc or other suitable material of the same size perforated
with holes at regular intervals, and is kept fixed with springs. The
material being transparent the holes in the zinc are seen through it, and
are a guide to the distributor of the discs or patches.
The latter aro by preference prepared as follows:-The ordinary a
blistering plaster of the pharmacopcia is thinly spread on sheets of the
same kind as those the preparation of which has been described above,
and covered with black tissue paper. The black tissue is well pressed
down on the plastered surface so as to cause it to adhere. With a punch,
pliers, or wad cutter, pieces or discs of a suitable size are cut out, and ;
having been distributed on a piece of wetted cotton cloth with their
gummed surfaces next it, they are picked up with a spatula and placed

page_text: on the prepared sheet stretched on the perforated zinc or suitable
material. The sheet with discs attached is then taken off the zinc and
pressed between pieces of bibulous paper so as to remove moisture and
cause them to adhere firmly. The sheets when quite dry are each folded
between pieces of white tissue paper and enclosed in a suitable envelope.
Having now particularly described and ascertained the nature and
object of my said Invention, and in what manner the same is to be per-
formed or put in practice, it must be understood that I do not limit or
confine myself to the use of exactly the same process or mode of manu-
facture herein-before described which I may vary as circumstances may
require, and I hereby claim the Invention of "New or Improved Manu-
facture of Omphalic Blisters," as herein-before described, the main
feature or principal distinctive characteristic whereof is so manufacturing
or making such omphalic blisters or plasters that the blistering portions
thereof shall be scattered over the surface, in manner hercin-before
described.
In witness whereof. I. the said Duncan Mackay, have hereunto
described.
In witness whereof. I. the said Duncan Mackay, have hereunto
set my hand and scal, this Twenty-seventh day of February, in
the year of our Lord One thousand eight hundred and seventy-
four
Witness,
ALEX. MUNRO,
52, Castle Street,
Inverness.
DUNCAN MACKAY, M.D. (L.S.)