IMPROVEMENTS IN THE MANUFACTURE OF EXTRACTS AND LIQUOURS OF LOGWOOD
Year: 1885

page_text: I CHARLES ELLERY AVERY of Jacksonville County of Duval State of Florida
United States of America Chemist do hereby declare the nature of my said
invention for IMPROVEMENTS IN THE MANUFACTURE OF EXTRACTS AND LIQUOURS
OF LOGWOOD and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
Heretofore logwood liquors as used by printers have been made without oxidation
to remove the hydrogen of the haematoxylin, or in other words to form haematein;
the liquor has been printed on the goods mixed with mordants that could oxidize
it, as the nitrates of copper or iron or chlorate of potash has been added to the
mixture of liquor and mordant, and the cloth steamed to develope the colour by
oxidation and unite the colour with the mordant. The same extraction process has
been mostly in use for the preparation of dyers' liquors and extracts, though some
manufacturers of greater skill “ cure " their wood in powder by wetting with
alkaline solutions, forming beds of the wet powder, often shovelled over to prevent
destruction of the dye by over-oxidation. The "cured" wood is then extracted as
usual. The object of my invention is to supersede the use of oxidants by the
printer, which often weaken the fibre of the goods; and to do away with the
'curing" process, which needs skilled labour, and much muscular power. The
curing" process usually leaves a part of the haematoxylin unavailable because not
oxidized into haematein, or a part becomes over oxidized, insoluble, and worthless
to the dyer, in fact both faults are to be found usually in the same liquor.
"
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I avoid substantially this loss.
:
To carry my invention into effect I extract the logwood as soon as cut, without
curing" partial "curing "does not render the oxidation of the liquor useless
but is unnecessary as the oxidation is much better effected in the liquor. To the
liquor I add a solution of any substance that is soluble and will oxidize haema-
toxylin to haematein by the removal of hydrogen. The bodies I prefer are, the

page_text: clear solution of bleaching powder, those of the chlorates and nitrates of the alkalies
and lime.
The chlorates in this operation appear to be reduced to chlorides and the nitrates
to nitrites. The solution of bleaching powder will do the work even if the liquors
are cold, but the chlorates and nitrates require a heated liquor, and work best under
pressure at beats above the boiling point. If acids or acid salts be added to the
mixture of logwood liquor and solution of chlorates or nitrates, the freed oxidizing
acids more readily oxidize at lower temperatures I prefer to use an oxidizar like
the nitrates or chlorates, whose solution may be thoroughly diffused through the
logwood liquor before oxidation takes place, as from increase of temperature or
addition of acids or acid yielding salts; for if the solutions of immediate oxidizers,
as of bleaching powder or of hypochlorous acid, be used, a portion of the haematein
formed returns to the oxidizer before all the haematoxylin is oxidized, and a loss
of dye ensues from over-oxidized haematein or unoxidized haematoxylin The
quantity of haematoxylin to be oxidized varies very much in different samples of
logwood, and its extract also, both from natural causes and from adulteration with
liquors glucose, molasses, extracts of bark &c.
The exact assay of haematoxylin is difficult, if possible; the readiest practical
means of ascertaining the quantity of any oxidizer to be used is to make an extract
of a known quantity of logwood or a solution of an extract; take a part, and add
to it the supposed required quantity of oxidizer and oxidize, to another part add
some more; to another part add some less; in the same water bath, to secure like
temperature, place three beakers containing like amounts of water and when at dyeing
heat, say 140° Fahrenheit or more, add like quantities by a small pipette of the three
liquors, liquor A to a beaker plainly marked A, liquor B to a beaker marked B &c.
In each, place a swatch of mordanted test cloth of equal size, large enough to
readily take up all the dye put in, a point easily found by the chemist or director
of works; if the most oxidized is deepest dyed, more oxidant is likely to be needed;
if the least oxidized is deepest dyed, less oxidation; if the medium oxidation is
deepest dyed, it is about right, and any variation should be on the side of the
swatch next deepest in shade.
By a few trials of this sort the amount of oxidizer is found and for that cargo of
wood or brand of extract, remains nearly the same in practice. A logwood yielding
ten per cent of haematoxylin will require about one and four tenths per cent of its
weight of the chlorate of potash and of other chlorates proportionally as their
contained oxygen, or of nitrate of soda nearly three per centum, other nitrates pro-
portionally as their contents of N. Os; a pound of haematoxylin requiring about
one nineteenth of its weight of available oxygen to develope its dyeing powers.
When the wood is "cured" in the ordinary way, the dye is wasted by lack of
oxidation or over-oxidation and often both ways. Where the dyer uses oxidizing
mordants both mordant and colour unite in the bath and are lost, or even if skil-
fully handled, much is loosely fixed on the goods, to the injury of the colours and
the goods. Here the loss is both in colour and in mordant. The oxidized liquor
acting on a mordant mechanically fast, yields a dye mechanically fast.
The printer using the oxidized liquor need no longer incur the risk of tendering.
of the fibre or the loss of colouring power by deficient oxidation of the dye.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The improvements in the manufacture of extracts and liquors of logwood,
herein before described which consist in oxidizing such liquors or extracts after
their extraction from the wood and before they are mingled with the necessary
mordants, by the formation of haematein from haematoxylin under the action of
oxidants such as, solution of bleaching powder, hypochlorous acid, chloric acid,
chlorates or nitrates of the alkalies and alkaline earths; as set forth.

page_text: 2. The improvements in the manufacture of extracts and liquors of logwood
herein before described which consist in oxidizing such, liquors or extracts, after
their extraction from the wood and before they are mingled with the necessary
mordant, by oxidizing substances, such as solutions of chlorates of potash or of lime,
or nitrates of potash soda or lime, which whilst mixing with the logwood liquors
at moderate temperatures oxidize slowly or not at all, but on raising the tempera-
ture particularly under pressure, or by the addition of acids or acid salts, become
oxidizers of haematoxylin to haematein as set forth.
Dated this twenty third day of June A.D. 1885.
PHILIP M. JUSTICE,
Applicant's Agent.