A METHOD OF PRESERVING FROM DESTRUCTION BY WORMS, INSECTS, DECAY, AND FIRE, CERTAIN VEGETABLE AND ANIMAL SUBSTANCES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, LEWIS
VERNET, of Buenos Ayres, 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 Twenty-fourth day of
April, 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
Lewis Vernet, my exors, adñors, and assigns, Her especial licence, full power,
sole privilege and authority, that I, the said Lewis Vernet, my exors, adññiors,
and assigns, or such others as. I, the said Lewis Vernet, my exors,. adñiors, 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, in the Islands of Guernsey, Jersey,
Alderney, Sark, and Man, and also in all Her said Majesty's Colonies and
Plantations abroad, my Invention of "A METHOD OF PRESERVING FROM
DESTRUCTION BY WORMS, INSECTS, DECAY, AND FIRE, CERTAIN VEGETABLE AND
ANIMAL SUBSTANCES;" in which said Letters Patent is contained a proviso
that I, the said Lewis Vernet, should 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
Majesty's High Court of Chancery within six calendar months next and
immediately after the date of the said in part recited Letters Patent, as in

page_text: 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
Lewis Vernet, do hereby declare that the nature of my said Invention, and
the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, that is to say :-
My Invention relates to a method of preserving from destruction vegetable
and animal substances by insects, worms, decay, and fire, by causing them to
be impregnated, washed, or merely moistened with or immersed in a simple
or compound solution of arsenic, according to the nature of the substances to
be preserved, or according to what they are to be preserved from.
I will first describe the simple solution of arsenic, and its application as
being of itself the most efficient, the most convenient, and the cheapest preser-
vative hitherto known against all kinds of worms or insects, even against the
voracious white ants, who in the East and West Indies, and in allmost all
tropical climates, are known to perforate at times, in a single night, whole
cases or bales of cotton, linen, silk, woolen, and other goods, and to perforate
in the course of a year or two the largest timber, & consuming its interior
substance, weakens it to such a degree as to cause it to break down of its own
weight; and also against the equally destructive worms & moths which attack
animal substances, especially skins, furs, and woolens; and against which white
ants, worms, and moths I have found, after minute trials & experiments
during several years, that all the weaker poisons are but very imperfect preser-
vatives unless applied in such large proportion as to render their use dangerous,
expensive, and otherwise attended with many inconveniences.
The simple
solution of arsenic I prepare by boiling in an iron, copper, earthen, or any
other convenient vessel some arsenious acid in any common spring or river
water, in the proportion of one pound of the acid to about forty gallons of
water, stiring it well untill it is dissolved & the liquor become transparent;
after which it is fit for use, and may be kept in casks or other convenient
vessels for many years without the least deterioration. Or I make a concen-
trated solution by boiling during four or five hours one pound of arsenic in
about five gallons of water, stiring it well all the time untill it is perfectly dis-
solved, and the liquid become transparent & clear. Care must be taken that
during the boiling the water lost by evaporation be constantly replaced, or that
the boiler or vessel be so constructed that the fire may not touch the dry parts of
the boiler, as otherwise the arsenic which deposits itself on such dry parts would
sublime, and might injure the lungs of the operators, whereas the vapour from the
water carries no arsenic with it, because the heat of boiling water is not sufficient

page_text: to cause the sublimation of arsenic. I mention these circumstances merely by
way of precaution, as they are well known to chemists. The concentration
may
be carried to a far greater extent by employing acid of arsenic. The concentrated
solution may also be kept for years in wooden or any other convenient vessels,
and when the solution is to be used it must previously be reduced by the
addition of water untill it arrives to the stated proportion of one pound of
arsenic to forty gallons of water. This weak solution of arsenic will be
sufficiently strong to preserve efficaciously all kinds of animal and vegetable
snbstances against any kind of insects or worms for any length of time, and as
long as the said substances exist. Most animal substances may be perfectly
preserved by still weaker solutions, say in the proportion of fifty gallons of
water to one pound of arsenic. But still weaker solutions than this I have
generally found to be imperfect preservatives. When the concentrated
solution looses by evaporation during its keeping it should be replenished by
adding water, so as to keep up the same proportion of five gallons of water to
every pound of the arsenious acid, as otherwise some arsenic will precipitate
and cristalise against the sides of the casks. A cold saturated solution contains
about three per cent. of arsenious acid. The reduced solution may also be
kept after having been made use of several times, as it never looses its pre-
servative virtue, although it may acquire sometimes a very feted smell.
Having thous described how I prepare the simple solution of arsenic, I
shall now proceed to explain how the same may be applied. I nearly fill a
tank or any convenient vessel with the diluted solution, or to every five gallons
of the concentrated solution of arsenios acid, which I put into the tank or
vessel, I add thirty-five gallons of cold water, and then dip the animal or
vegetable substances for a moment in the solution, and then spread them thinly
out to dry. An hour or two of exposure in a good sun is generally sufficient,
to dry them well. The solution thus dried upon said substances covers their
surface or fibres with an invisible to the sences imperceptible coat of arsenic,.
yet of sufficient strength to prevent the insects from attempting to penetrate
through it, unless the solution employed is weaker than what I have prescribed,
in which case the insects may at times penetrate and destroy the substances.
Notwithstanding this wonderfull efficacy of this poison against all insects, I
have found that the immediate or mediate contact with the substances which
have been prepared with my weak solution of arsenic is not in the least
injurious to animal life or health, a proof of which is, that insects and worms
will live with impunity among the thus prepared substances for several months
without injuring such- substances in the least, and ultimately they will leave
them to seek for food elsewhere. If unprepared substances are mixed with

page_text: the prepared substances, the former will be destroyed by the insects, and the
latter will remain perfect... Men can also live day and night for a considerable
period of time in apartements which are nearly filled with substances prepared
in said weak solution of arsenic without their health suffering the slightest
injury. All these facts I have ascertained through a long study of the
subject, directing my attention more especially to reducing the solution to the
greatest posible weakness, & without loosing its preservative power against
insects. However, the degree of weakness may yet-be increased according to
the kind of insects to be guarded against, to the longer or shorter time that
substances are to be preserved, and to other peculiar circumstances, which
degrees of weakness will soon be taught by experience when my method may
have come into actual practice, and on a large scale. I therefore do not
limit my claim to the proportions which I have mentioned already, and which
I shall mention in the sequel of this Specification; neither do I limit myself to
any particular modes of applying the arsenical solutions, because the workmen
will soon adopt the most convenient modes of using them ou large scales.
Manufactured cotton, linen, silk, woolen, paper, leather, and other goods,
might more properly be prepared in the arsenical solutions at the time they
are undergoing their last washing, rincing, or dying operation by adding to
the liquid for such operation a sufficient quantity of arsenic, always in the
stated proportion of forty gallons of the liquid to one pound of the arsenic,
boiling the same in the liquid if it has been added in the state of dry arsenious
acid, and untill it is perfectly dissolved. Finished cloths may be conveniently
prepared against the moth by applying the said solution lightly by the means
of a brush dipt in the solution. In all cases where quick drying is desirable,
or when putrefaction threatens substances, I add to the solution about six
pounds of allum to every pound of arsenic. But the addition of allum is very
seldom necessary. Wood may also be preserved against all sorts of insects
& worms by applying the solution of arsenic to its surface by washing or
momentary immersion, provided the insects do not already exist in the interior
of the wood, or provided the exterior thin coat of arsenic be not mecanically
removed. But to preserve wood effectually-it should be saturated in the said
solution of arsenic by immersion in tanks for a longer or shorter time, say
from one to thirty days, according to the thickness of the timber, or it should
be saturated with the arsenical solution in close vessels by exhaustion &
pressure, as is practised with other solutions in the Royal Dockyard and else-
where, or by pressure not yet practised, as columnial atmospheric steam or
condensed air pressure. In order to preserve wood from receiving injury under
water from worms, & from the water itself, I impregnate the wood in the

page_text: same way with a solution composed of arsenic, boiled in any thin, oily, or
tarry substance, in the proportion of two pounds of arsenic, more or less, to
two hundred pounds of such oily or tary matter, by which compound the wood
is protected against the worms, which the oily & tarry matters alone could but
very imperfectly effect, and the arsenic is preserved from dissolving under
water by its combination with the oily matters. To render wood also less
inflamable, the arsenical solution should be combined with six pounds of
allum and ten pounds of potash to every pound of the arsenic contained in-the
solution.
Having thus explained the nature of my Invention, and the manner of
applying it, I wish it to be well understood that I claim as my Invention the
use of the weak simple solutions of arsenic which I have described for
preserving such animal and vegetable substances as have not hitherto been
preserved by such weak solutions of arsenic against insects and worms; and that
I also claim the use of solutions of arsenic when applied in conjunction with
oily or tary matters, or with any mineral solutions, for the purpose of preserving
animal and vegetable substances from insects, decay, & fire, as an improvement
to the hitherto employed methods.
In' witness whereof, I, the said Lewis Vernet, have hereunto set my
hand and seal, this Eleventh day of July, in the year of our Lord One
thousand eight hundred and forty-nine.
Taken and acknowledged, by Lewis
Vernet (party hereto, at Buenos
Ayres, the Eleventh day of July,
One thousand eight hundred and
LEWIS (L.S.) VERNET.