NEW-INVENTED METHOD OF RECTIFYING SPENT LEES PROM WHICH SOAP HAS BEEN MADE, AND RENDERING THE SAME OF A QUALITY TO MAKE SOAP AGAIN
Year: 1780

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, greeting,
JOHN MITCHELL, of Oakley, in the Parish of Saint Lawrence, Wooten, in the
County of Hants, Gentleman, sends greeting.
WHEREAS the King's most Excellent Majesty, by Letters Patent under
the Great Seal of Great Britain, bearing date the Thirtieth day of March
last, gave and granted unto the said John Mitchell, his exors, admors, and
assigns, His Majestie's special licence, full power, sole priviledge and authority,
for the said John Mitchell, his exors, admors, and assigns, and every of them,
by himself or themselves, or by his or their deputy or deputies, servants or
agents, or such other as he, the said John Mitchell, his exors, adñiors; or
assigns, should at any time agree with, not exceeding the number of five,
and no other, from time to time and at all times during the term of
years therein expressed, to make, use, exercise, and vend his "NEW-INVENTED
METHOD OF RECTIFYING SPENT LEES PROM WHICH SOAP HAS BEEN MADE, AND
RENDERING THE SAME OF A QUALITY TO MAKE SOAP AGAIN;" to have, hold, and enjoy
the said licence, power, privilege, and advantage to the said John Mitchell, his
exors, admors, and assigns, for the term of fourteen years from the date of the
said Letters Patent next immediately ensuing, and fully to be compleat and
ended, according to the Statute in that case made and provided; in which
said Letters Patent is contained a proviso, that if the said John Mitchell

page_text: should not particularly describe and ascertain the nature of the said Invention,
and in what manner the same is to be performed, by an instrument in
writing under his hand and seal, and cause the same to be inrolled in His
Majestie's High Court of Chancery within four calendar months next and
immediately after the date of the said Letters Patent, that then the said
Letters Patent, and all liberties and advantages whatsoever thereby granted,
should utterly cease, determine, and become void.
NOW KNOW YE, that I, the said John Mitchell, in pursuance of the
said proviso in the said Letters Patent contained, do declare that the nature of
my said Invention of Rectifying Spent Lees from which Soap has been made,
and rendering the same of a Quality to make Soap again, and the manner in
which the same is to be performed, is as follows; that is to say:-
My process for making soap by using spent lees consists in manufacturing
it in the usual manner, as in making common pottash, in either of the cases
following: 1st. Burn the spent lees with helm, straw, or some other vegetable
or inflamable matter in the usual manner for making common pottash with or
without an additional alkaline; or otherwise boil such spent lees with or
without an additional alkaline and calcine of flux. The salt so obtained by either
process, it will rectify the spent lees to be of a soap making utility. 2d. The
uncertainty of knowing the various degrees of strength of the preceeding
process for making of soap makes it impossible to prescribe a rule that may
be universally necessary to adjust the additional quantity of alkaline salt
proper to be used in compound with such spent lees, as in proportion to
the various degrees of the strength of the soap the lees will be blended
with more or less quantity of common sea salt, or some salt similar to sea
salt, used for graining, by which the lees will contain a quantity of neutral
salt, more or less, in proportion to its bulk, and the kitchen stuff used therein
will require in the several operations more lees than ordinary tallow, and
ordinary tallow will require more lees than fine tallow. From these circum-
stances of the various degrees of quality and quantity of salts contained in the
spent lees, it is impossible to ascertain with precision the quantity of alkaline
salt that will be necessary to rectify such spent lees. 3d. But if the following
particulars are adhered to, notwithstanding the difficulty of adjusting an exact
necessary quantity of alkaline salt, such spent lees may be rectified to a
proper quality for making soap with raw tallow, kitchen stuff, or any other
unctious matter. 4th. The spent lees may be burnt with an addition of pure
alkaline salt; ; and if the soap is made very strong, the spent lees may be rectified
without an additional alkaline; 5th, or with an additional alkaline salt, altho
not perfectly pure from a mixture of heterogeneus matter; 6th, or with ar

page_text: '
alkaline salt, altho' mixed with a portion of acid, if such acid be not be not to
great in quantity to render such spent lees of a quality to neutral. 7th. To the
spent lees of a hundred of tallow, uniting the essence of any quantity of
wood ashes, from the least quantity to one, two, three, four, five, or six
bushels, or more generally six bushell of wood ashes will be sufficient
to rectify the spent lees of an hundred of tallow; for working a future
hundred of tallow, or adding of a vegetable or a fossil alkaline salt to
such spent lees, of a quantity adequate to the essence of six bushels of
wood ashes, will answer the same purpose for rectifying such spent lees as
six bushels of wood ashes. 8th. But the various quality and quantity of
such spent lees, and the various strengths of the ashes, make it necessary to
leave the quantity of ashes to be used to be ascertained by the soap maker,
as experience may direct him, by an accustomed knowledge of his working the
process, and as the usual strength of the wood ashes or other alkaline salt,
used with the spent lees, may determine. 9th. Likewise the quantity of the
alkaline mixt with a heterogeneous matter, cannot be ascertained, but must be
left to the experience of the workman. 10th. Neither can the alkaline salt
mixt with an acid, if a proper or improper acid to be used, be ascertained
what quantity may be necessary, but must be left to the experience of the
workmen. 11th. When the spent lecs are rectified by burning with or
without an additional alkaline salt, let the saline substance, in general termed
pottash, be prepared with lime in the usual manner, as is customary for
preparing common pottash or barrilla ash for soap making. When so prepared
with water, procure a lee in the usual manner for soap making, and the lees
so obtained will be of a soap-making quality. 12. Different vegetables are of
different qualities, and as various are the strengths of the fixed alkaline salt,
according to the different species, which makes it impossible to ascertain the
exact quality or strength of the lees necessary for an hundred of tallow, even
if the quantity and quality of the tallow in various operations are identically
the same.
13th. And what renders the impossibility of ascertaining the
necessary exact quality and strength of the lees more difficult is, that the
various parcels of tallow or kitchen stuff are of various qualities, some requiring
more lees and more strength than others, a due proportion of which must
depend on the experience of the workman. 14th. But the following par
ticulars will be a guide of more general use than has been hitherto known in
the present practice of soap making, forasmuch as it makes the soap more
perfect than is done by the present practice. 15. Soap may be framed with no
more than one operation, or with two operations, as is the general practice; but
it is acknowledged by the most skilful soap makers that three operations

page_text: make soap more perfect than is possible by fewer operations. Supposing the
quantity of lees in the several operations of such process are equal, I have
always found that three operations are necessary and sufficient, provided a due
quantity of lees has been used and no more, but the workman may work by as
many operations as his discretion may direct. 16th. For begining the process
for re-using the lees manufactured from the spent lees, as before directed, first
add any quantity of tallow &c. &c. &c. in the usual manner, as is the custoni
for cleansing foul tallow, &c. &c. in the general practice to the spent lees of a
preceeding making or makings of soap, with the addition of other lees, or
without the addition of other lees. Boil the compound the usual time, one hour
more or less, as is usual. 17th. It is my method to separate the soapy matter
of such operation as free as possible from the lees with which it has boiled,
then for every hundred of tallow so boiled with such spent lees add thereto of
a strong lee as before directed, No. 11, just drained from the lime and ashes
that will float a new laid egg, to appear above the surface as near as can be,
equal to the mean breadth of a sixpence and a shilling, such quantity more or
less, as experience may direct. My usual quantity for such purpose is twelve
gallons wine measure. Let such lees and soapy matter be heated for incorpo-
ration according to the general practice, and for an incorporation add of the
same lees, quality and strength as the last directed, any quantity may be found
necessary for incorporation, adding such lees gradually as the mass becomes of
a boiling heat. When so incorporated, grains with strong lees, brine, or common
salt, and boil according to the general practice. 18th. If a second operation
is intended, let the soap be perfectly separated from the lees beneath it, and to
the soap add of the same lees in quality and strength as the last mentioned,
No. 11, any quantity at discretion. My usual quantity is from 20 to 40 gallons,
according to the causticity in the operation on the tongue, until a little pungent;
when incorporated, grain it with strong lees, common salt, or brine, and boil
it according to the general practice. 19th. If a third operation is intended,
separate the soap from the lees beneath it, and to the soap add of the same
lees, in quality and strength as the last mentioned, any quantity at discretion.
My usual quantity is from 20 to 50 gallons, without any attention as to it's
pungency when incorporated grain it with strong lees, common salt, or brine,
and boil it according to the general practice. 20th. If tallow is to be used
with clean strong lees without boiling with the spent lees, then, for every
hundred of tallow, first add any quantity at discretion of strong lees that will
float a new laid egg almost sideways; my usual quantity is 12 gallons wine
measure; then add lees of a quality and strength the same as the lees above
directed, No. 17, and proceed for graining as there directed; likewise the

page_text: 2d & 3d operations may be worked as above in No. 18 & 19. 21st. If the spent
lees are not compounded before or at the immediate time of burning, and it is
supposed that an additional alkaline is necessary, 6 bushels of wood ash or an
adequate quantity of alkaline, as mentioned above in No. 1, may be used with
pottash and lime. In this case the quantity of wood ashes I generally use six
bushels, or an adequate quantity of some other alkaline salt. 22d. Or if the spent
lees are not compounded with an additional alkaline before or at the immediate
time of burning, as above directed, No. 1, or the potash so made by burning
is not compounded with an additional alkaline in the preparation of such
potash lime as directed, No. 11, then the lees obtained from such spent lecs
pottash may be compounded, if an additional alkaline is necessary, by adding
fifteen gallons wine measure, more or less, of strong lees drawn from wood
ashes, or an adequate quantity of lees equally alkaline thereto.
In witness whereof, I have hereunto set my hand and seal, this Twenty-
fifth day of July, One thousand seven hundred and eighty.
AN
BE IT REMEMBERED, that
venty-nin day
the
year of our Lord 1780, the aforesaid John Mitchell came before our said
Lord the King in His Chancery, and acknowledged the Specification aforesaid,
and all and every thing therein contained and specified, in form above written.
And also the Specification aforesaid was stampt according to the tenor of the
Statutes made in the sixth year of the reign of the late King and Queen
William and Mary of England, and so forth, and in the seventeenth year of
the reign of His Majesty King George the Third.
Inrolled the Twenty-seventh day of July, in the year of our Lord One
thousand seven hundred and eighty.