Year: 1888

page_text: I, VICTOR RIVIERE of Newark (No. 84, Prospect Street), in the County of Essex
and State of New Jersey, United States of America, tanner, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement :-
My invention has relation to the treatment of hides and skins after they have been
tanned and before they have been colored, and the object is to render the skins
permanently soft and flexible and waterproof, and at the same time leave a mordant
in the skin to combine with the subsequent coloring matter used, and to these ends the
novelty consists in the process and the product of the same as will be hereinafter
more fully described and particularly pointed out in the claims.
In carrying out my invention I first make a neutral or basic solution of the
sesquioxide of chromium in a suitable vat and add an excess of the salt so as to
always have three or four inches of the excess in the bottom of said vat. I then make
a saturated solution of the nitrate of iron, and to about one hundred gallons of the
chromium solution I add about five (5) to ten (10) gallons of the iron solution, and
mix thoroughly by agitation.
I now take the skins fresh from the tan vat and wash them in warm water to which
has been added an alkali to neutralize the acid used in tanning and to render the
skins neutral.
I then suspend the skins in this solution from five to fifteen hours or until the
skins have had deposited in them a sufficient quantity of the finely divided
sesquioxide of chromium and nitrate of iron, as the organic nature of the leather
has the property of absorbing the oxide in solution, setting the acid free and
depositing the salts in the leather, which forms a mordant for the subsequent

page_text: coloring process, and so changes the organic nature of the leather as to render it
permanently soft and flexible and at the same time waterproof. The skins may now
be removed and colored in the usual manner.
The sesquioxide solution is then agitated so that the free acid will combine with a
portion of the excess of salt in the bottom of the vat, and the whole allowed to settle
previous to a fresh batch of skins being introduced.
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
1st. The process herein described of treating skins which consists in first tanning
the skin, then subjecting it to a solution of the oxide of chromium and nitrate of iron,
as set forth.
2nd. The process herein described which consists in first tanning the skin, then
treating it with a solution of oxide of chromium and nitrate of iron, and dyeing with
a color which will combine with the chromium oxide as a mordant, as set forth.
3rd. As a new article of manufacture, the product of the above process which
consists of a tanned skin impregnated with oxide of chromium and nitrate of iron, as
set forth.
4th. As a new article of manufacture, a tanned skin having its pores impregnated
with oxide of chromium and nitrate of iron and dyed with a color partly combined
with the chromium oxide, and iron, as a inordant, as set forth.
Dated at Washington, District of Columbia, United States of America, this Ninth
A T 1000