IMPROVEMENTS IN THE MANUFACTURE OF VARNISHES FROM RESINOUS SUBSTANCES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
CASTLEY, of Harpenden, in the County of Hertford, Manufacturing Chemist,
send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of the United Kingdom of Great
Britain and Ireland, bearing date at Westminster, the Eleventh day of
January (One thousand eight hundred and forty-nine), in the twelfth year
of Her reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said James Castley, my exors, adññors, and assigns, Her especial
license, full power, sole privilege and authority, that I, the said James
Castley, my exors, adñiors, and assigns, and such others as I, the said James
Castley, my exors, adññiors, or assigns, should at any time agree with, and no
others, from time to time and at all times during the term of years therein
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, and in the Islands of
Jersey, Guernsey, Alderney, Sark, and Man, and in all Her Majesty's Colonies
and Plantations abroad, my Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF VARNISHES FROM RESINOUS SUBSTANCES;" in which said Letters Patent is
contained a proviso, that I, the said James Castley, shall cause a particular
description of the nature of my said Invention, and in what manner the same
is to be performed, by an instrument in writing under my hand and seal, to be
inrolled in Her said Majesty's High Court of Chancery within six calendar

page_text: months next and immediately after the date of the said in part recited Letters
Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
James Castley, hereby declare that the nature of my said Invention, and in
what manner the same is to be performed, are fully described and ascertained
in and by the present Specification thereof, that is to say :-
My Invention consists, firstly, in manufacturing in manner following,
from rosin spirit and the gum resin called gutta percha or gutta tuban,
a new compound or varnish which possesses the properties of being strongly
adhesive and perfectly water repellent. I put into a pot three parts by
weight of the gutta percha or gutta tuban as imported, or as it may be
bought in the home market, and add nine parts of crude rosin spirit (obtained
by the destructive distillation of common rosin), and subject them to a heat of
from one hundred and twenty degrees to one hundred and forty degrees of
Fahrenheit, stirring the mixture occasionally. The resulting solution forms
a varnish which answers well for the coating of all coarse fabrics, such as
tarpaulings, rick cloths, &c.; but to obtain a varnish of a purer and better
quality, suitable for fine articles, I substitute, in the preceding process, for the
crude rosin spirit a rectified rosin spirit, which I obtain by passing a current
of steam through the crude rosin spirit until the condensed product which
comes over exhibits a specific gravity of about 0-870, at which point the
process of distillation must be stopped, all products of a higher specific gravity
being injurious to the quality of the spirit.
And, secondly, my Invention consists in manufacturing a colorless varnish
in manner following, from gum damar and rosin spirit, or from gum mastic
and rosin spirit. I first take rosin spirit which has been rectified by steam,
as before described, and mix with it from one-tenth to one-sixth its weight of
sulphuric acid, of not less specific gravity than 1-700, and agitate the mixture
well, after which I rectify the spirit over again by means of a current of
steam, as before, when the spirit comes over in a colorless state; I finally
dissolve the gum damar or gum mastic in about four times its weight of this
purified rectified spirit with the aid of a gentle heat. A varnish of an inferior
sort may be obtained by using rosin spirit which has undergone one process of
rectification only, and not been treated with the sulphuric acid.
And having now described the nature of my said Invention, and in what
manner the same is to be performed, I declare that though I have before
stated the proportions in which I find from experience gutta percha, gum.
damar, and
gum niastic may each best be combined with the rosin spirit, yet.

page_text: that I do not confine myself to any precise proportions, because varnishes may
be formed from combining them with any portion of spirit in which they are
respectively soluble. I declare also that I make no claim to either of the
processes of rectification and purification of the rosin spirit before described.
And I declare that what I claim as of my Invention is as follows:-
First, I claim the manufacture of the new varnish compounded of gutta
percha and rosin spirit (crude, rectified, or purified), as before described.
And, second, I claim the manufacture of the new varnishes compounded of
gum damar and rosin spirit, or of gum mastic and rosin spirit, whether such
spirit is rectified and decolorized or rectified only, as before described.
In witness whereof, I, the said James Castley, have hereunto set my
hand and seal, this Eleventh day of July, in the year of our Lord One