IMPROVEMENTS IN THE PROCESS OF CONVERTING HIDES AND SKINS INTO LEATHER
Year: 1879

page_text: LETTERS PATENT to James Dayer, of Bermondsey, in the County of Surrey,
Pratical Tanner, for the Invention of "IMPROVEMENTS IN THE PROCESS OF
CONVERTING HIDES AND SKINS INTO LEATHER."
PROVISIONAL SPECIFICATION left by the said Jamer Dayer at the Office of
the Commissioners of Patents on the 3rd October 1879.
JAMES DAYER, of Bermondsey, in the County of Surrey, Practical Tanner.
"IMPROVEMENTS IN THE PROCESS OF CONVERTING HIDES AND SKINS INTO LEATHER."
If the hides or skins to be tanned have been salted or otherwise treated, I soak
or steep them in a pit of ordinary dimensions containing cold water for about
twenty four hours, and I then put them into another pit having therein a solution
of lime in water in the proportion of about two bushels of lime, instead of about
five bushels thereof, to the quantity of water generally used in a pit, and the bides
or skins are soaked therein for about eighteen hours, and I then take them out and
put into that lime solution about two ounces of an admixture of pearl ash and soda
ash, in the proportions of about one ounce and a half of pearl ash to half an ounce
of soda ash. This solution should be well stirred or plunged, and the hides or skins
are soaked therein for about eighteen hours, and then taken out and drained for
about three hours, and afterwards again soaked in the same solution for about fifty
seven hours, when they are removed to the beam and unhaired and fleshed, and
when that has been done they are put into another pit containing a solution of the
admixture of pearl ash and soda ash in water in the proportions above mentioned
for about one to two hours; they are then taken out and worked on a beam to
remove the impurities, and afterwards washed with lukewarm water for a few
minutes, and ultimately put into a pit containing the tanning liquor, and handled
as usual for about three weeks for dressing leather, and for much less time for
lighter skins, and for about six weeks for sole leather, and then dried as usual. If
the hides or skins be raw they may be put into the lime pit at once without
previous washing. Although I have stated approximately the proportions of the
lime and pearl ash and soda ash and the duration of times required for the several
steps in the process of tanning, it must be understood that these will necessarily
vary according to the quality of the ingredients, the nature of the water, and the
state of the hides or skins to be operated upon.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Dayer in the Great Seal Patent Office on the 3rd April
1880.
JAMES DAYER, of Bermondsey, in the County of Surrey, Practical Tanner.
"IMPROVEMENTS IN THE PROCESS OF CONVERTING HIDES AND SKINS INTO LEATHER.”
If the hides or skins to be tanned have been salted or otherwise treated, I soak
or steep them in a pit of suitable capacity containing cold water for about twenty
four hours. The pits in tan yards vary considerably in capacity, and therefore to
render my process intelligible I will suppose, for the sake of illustration, that the
pit is six feet long by four feet wide, and three feet six inches deep, filled with
water up to the height of two feet six inches from the bottom to allow space for
the immersion of the hides or skins. The quantity of water therein will be equal
to about sixty cubic feet, or three hundred and seventy four gallons of water, or
thereabouts, and I add thereto about two bushels of lime, and in some cases I soak
the hides or skins therein for about eighteen hours, and I then take them out and
add to such lime solution three ounces of pearl ash of commerce (which is an impure
carbonate of potassa or potash) by avoirdupois weight, being at the rate of about
one ounce of pearl ash to every one hundred and twenty five gallons of water, and
one ounce and a half of soda ash of commerce, which is an impure carbonate of
soda, by like weight, being at the rate of about half an ounce to every one hundred
and twenty five gallons of water, and then resoak the hides or skins therein for
about twenty one hours; but I generally prefer to soak the hides or skins in the
first instance in the above mentioned solution of lime, pearl ash, and soda ash for
about twenty one hours instead of in the lime solution, and then to take them out
and drain them for about three hours, and afterwards to resoak them in the same
admixture for about fifty seven hours, and thereupon to remove them to the beam
to be unhaired and fleshed, and when that has been done to put them into another
pit, which for illustration I will suppose to be of like capacity, containing three
hundred and seventy four gallons of water, to which the like quantities of pearl ash
and soda ash as before mentioned have been added, and to soak the hides or skins
therein for about one to two hours, and then to be taken out and worked on a
beam to remove the impurities, and afterwards to wash them with lukewarm water
for a few minutes, and ultimately to soak them in the ordinary tanning or vegetable
astringent liquor in a pit of capacity suitable for the number of hides or skins to
be put therein, for about three weeks for skins to be tanned as dressing leather,
and for a much less time for lighter skins, and for about six weeks for sole leather,
and finished by drying as usual. If the hides or skins be raw they may be put
into the pit containing the lime, pearl ash, and soda ash solution at once without
previous washing. The hides or skins should be well handled in every pit in
which they are immersed.
The celebrated W. T. Brande, Professor of Chemistry in the Royal Institution of
Great Britain, &c., &c., &c., states in his Manual of Chemistry, Edition 1848, page
591, that carbonate of potassa is known in commerce in different states of purity
under the names of woodash, potash, pearlash, and subcarbonate of potassa.
I have stated approximately the proportions of lime, pearlash, and soda ash to a
given quantity of water, and the duration of time required for the several steps in
the process of tanning, but it must be understood that these will necessarily vary
according to the nature and condition of the hides or skins to be operated upon, the
quality of the lime, pearlash, and sodaash, the character of the water, and the state
of the weather.
Having described the nature of my said Invention, and in what manner the same
can be performed, I wish it to be understood that what I claim as my Invention is,

page_text: 1. The conversion of hides and skins into leather by means of the process
substantially as hereinbefore described.
2. The employment of pearlash and soda ash for the purposes aforesaid, sub-
substantially as herein before described.
In witness whereof, I, the said James Dayer, have hereunto set my hand and
seal, this Third day of April, One thousand eight hundred and eighty.
JAMES DAYER.
(L.S.)