AN IMPROVED METHOD OF PREPARING OR TREATING CERTAIN DYE-STUFFS SO AS TO OBTAIN GREATER DYEING POWER
Year: 1855

page_text: LETTERS PATENT to Francis Leeshing, of Busby, near Glasgow, in the
County of Lanark, Chemist, for the Invention of "AN IMPROVED METHOD
OF PREPARING OR TREATING CERTAIN DYE-STUFFS SO AS TO OBTAIN GREATER
DYEING POWER."
Sealed the 3rd August 1855, and dated the 23rd May 1855.
PROVISIONAL SPECIFICATION left by the said Francis Leeshing at the
Office of the Commissioners of Patents, with his Petition, on the 23rd
May 1855.
I, FRANCIS LEESHING, of Busby, near Glasgow, in the County of Lanark-
shire, Chemist, do hereby declare the nature of the Invention for "AN IMPROVED
METHOD OF PREPARING OR TREATING CERTAIN DYE-STUPPS SO AS TO OBTAIN GREATER
DYEING POWER" to be as follows:-
The nature of my Invention consists in a new mode of improving the
dyeing qualities of certain dye-stuffs, such as dye woods, barks, berries,
herbs, or extracts of dye woods, barks, berries, herbs, or other vegetable
productions useful in dyeing, with the exception of madder roots. The
said improvement being effected by boiling those dye-stuffs with diluted
sulphuric acid or inuriatic acid, when after cooling the liquid portion is to be
removed, as also the acid still adhering to the solid ingredients, by means of

page_text: apparatus suitable for filtration, washing, and squeezing. Though I give the
preference to the treatment just described, I sometimes boil those dye-stuffs
first with diluted alkalies, and by adding afterwards the mineral acid in such a
quantity as to impart to the mixture a strongly acid taste; or I may modify
the previously described process, by boiling first with acids and afterwards
add a quantity of alkalies to neutralise the acid; adopting either of these
modifications, the liquid portion is to be removed from the solid part, and
the latter subjected to washing and squeezing, as in the first-described process.
The solid portion thus obtained forms the prepared dye-stuff now ready for
use, and may be employed either in the wet state, with or without the addition
of small quantities of alkali, or it may be dried and preserved.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Francis Leeshing in the Great Seal Patent Office on the
22nd November 1855.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANCIS
LEESHING, of Busby, near Glasgow, in the County of Lanarkshire, Chemist,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-third day of May, in the year of our Lord
One thousand eight hundred and fifty-five, in the eighteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Francis Leeshing, Her special licence that I, the said Francis Leeshing,
my executors, administrators, and assigns, or such others as I, the said Francis
Leeshing, 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 term 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 "AN IMPROVED METHOD
OF PREPARING OR TREATING CERTAIN DYE-STUFFS SO AS TO OBTAIN GREATER DYEING
POWER," upon the condition (amongst others) that I, the said Francis Leeshing,
by an instrument in writing under my hand and seal, 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.

page_text: NOW KNOW YE, that I, the said Francis Leesbing, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof (that is to say) :-
My Invention chiefly refers to the drugs known in commerce as quercitron
bark, weld, and flavine, and consists in improving the dyeing qualities of those
drugs, by boiling them with diluted acids (or with saline or metallic solutions
containing portions of free acid or yielding portions of free acid during boiling),
or in boiling them first with weak solutions of caustic soda or potash or
ammonia, or of carbonate of soda or potash or ammonia, and subsequently
with acids. But although most of the mineral acids (with the exception of
nitric acid) and several saline and metallic solutions containing free or
uncombined acid or yielding portions of free acid during boiling may be
employed either alone or after the previous treatment of the dye-stuffs with
alkalies, I prefer the sole application of either sulphuric acid or muriatic
acid, as offering most advantage, both in regard to economy and quality of
product. After the boiling and cooling, the acid liquid is removed from the
solid part by filtration or decantation, and the latter is subjected to repeated
washings with cold water until it is thoroughly freed from the adhering acid,
(or the acid liquid before being subjected to filtration may be neutralized with
carbonate of soda or potash or ammonia, or with caustic soda or potash or
ammonia, and then filtered and washed.) In either case the ingredients
remaining upon the filter or at the bottom of the vessels after decantation are
now to be deprived as much as possible of the adhering moisture by the
application of pressure, and after this they may either be employed at once for
dyeing, or they are dried and preserved for the same purpose.
But that my Invention should be fully understood, I shall now describe
the further particulars of carrying out the process I have indicated in the
foregoing lines; and although I do not confine myself to the precise details or
the exact quantities to be mentioned, or to any special apparatus, I would give
the preference to those to be described in the following
In a wooden tub or in a leaden pan holding about eight hundred gallons, I
give from four hundred to five hundred gallons of water and one hundred-
weight of sulphuric acid of 1.830 sp. gr., or two hundredweight of muriatic
acid of 1.192 sp. gr., and five hundredweight of the drug intended for the
operation (either quercitron bark, flavine, or weld, as the case may be,) in a
ground or finely divided state. After the whole has been well mixed, steam is
allowed to pass through the mixture by means of a leaden pipe reaching with
the one end nearly to the bottom of the tub, the other end being connected

page_text: with a steam boiler. After the temperature had been raised to 212° Fahrenheit
the boiling is continued for about three quarters of an hour or one hour longer,
when the whole is run off into a wooden trough and mixed with a further
quantity of cold water (about twice as much as has been used for the boiling).
When, after cooling, the solid matter has settled to the bottom, the acid liquor
is run off from the top, and the trough filled again with water, and the whole is
stirred up. After decantation the water is again removed in the same way and
renewed once more, and after the removal of this the remainder is generally
found sufficiently free from acid. It is now either thrown upon a suitable filter
or filled into bags, and allowed to drain for a time, after which it is subjected
to pressure, in order to remove as much as possible of the adhering moisture.
The material so obtained is now ready to be used either directly for dyeing, or it
is to be dried by artificial heat, not exceeding 212° Fahrenheit, and preserved
for the same purpose.
The treatment described just now may be modified so as to heat or boil the
dye-stuff's mentioned in the foregoing with weak solutions of alkalies previously
to the application of acids. In this case I employ for five hundredweight of
the dye-stuff's intended for operation thirty pounds of crystallized carbonate
of soda, or corresponding quantities of carbonate of potash or ammonia, or of
caustic soda or potash or ammonia, and four hundred gallons of water. After
having boiled this mixture for a quarter of an hour, I add one hundred and
twenty-two pounds of sulphuric acid of 1-830 sp. gr., or two hundred and forty-
four pounds of muriatic acid of 1.192 sp. gr., and boil for three quarters of
an hour longer, when the whole is run off, cooled, and treated in the same
way as described before.
The dye stuffs prepared according to either of these modifications I proposo
to call, when obtained from quercitron bark, quercitrine; when obtained from
flavine, flavetine; and that from weld, luteoline. They distinguish themselves
from the original drugs by being free from those constituents which are known
to interfere with their use in dyeing (such as tannine and lime); but the
coloring matters contained in those drugs have at the same time undergone a
change and acquired new properties, which are exhibited by their increased
affinity for mordants, and their yielding brighter and much richer shades in
dyeing; and though much less soluble in either cold or hot water, they show
themselves now much better adapted for those branches of dyeing where the
temperature has to be raised to boiling than is the case with the original
drugs.
Having now fully described the nature of my said Invention, and the
manner of carrying the same into practical effect, I wish it to be understood

page_text: that I do not confine myself to the precise details, nor to the apparatus herein
described, and I am fully aware that similar treatment and apparatus as
described has been applied previously to madder roots; what I claim, there-
fore, is, the boiling or heating with acids (either alone or subsequently to the
use of alkalies) of dye-stuffs other than madder root, and such as named above,
and the application of the materials obtained after the boiling and separating
from the acid liquors, as improved dye-stuffs for practical use in dyeing.
In witness whereof, I, the said Francis Leeshing, have hereunto set my
hand and seal, this Fifteenth day of November, in the year of our Lord
One thousand eight hundred and fifty-five.
Witness,
DAVID SMITH, J. P.,
Glasgow.
FRANCIS LEESHING. (L.s.)