A NEW OR IMPROVED BLEACHING AGENT, ALSO APPLICABLE FOR OTHER PURPOSES, TOGETHER WITH THE MODE OF AND APPARATUS FOR PRODUCING THE SAME
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by Daniel Collet at the Office of
the Commissioners of Patents, with his Petition, on the 21st June
1870.
I, DANIEL COLLET, of 13, Boulevart St. Martin, Paris, in the French
Empire, Proprietor, do hereby declare the nature of the said Invention
for "A NEW OR IMPROVED BLEACHING AGENT, ALSO APPLICABLE FOR OTHER
PURPOSES, TOGETHER WITH THE MODE OF AND APPARATUS FOR PRODUCING THE
SAME," to be as follows:-
The present mode of bleaching wool, silk, and straw consists in
submitting these materials to the action of vapors produced by the
combustion of sulphur in chambers or apparatus constructed for the
purpose. This method is inapplicable in many instances, and this
Invention has for its object to provide a means of bleaching wool, silk,
and straw which may be easily applied in all cases. The Invention
consists in the application for bleaching wool, silk, and straw, and for
the sulphuration of casks, vats, and syrups of an aqueous solution of
sulphurous acid gas, which product has never been hitherto employed
for these purposes. This solution possesses the same bleaching qualities

page_text: as the vapors of sulphur, and requires no special apparatus for its use.
The following is the method of manufacturing this improved bleaching
agent, reference being had to the accompanying Drawing. a shows a
furnace constructed of brickwork or fire-clay, on the sole of which
sulphur is to be burnt; or I may roast a sulphuret therein. The furnace
is closed, but is provided with two openings, one for the supply of air
and sulphur, and the other for the escape of gazeous sulphurous acid
through a pipe b, which passes down into a chamber c containing water.
At the upper part of this chamber (which is closed) there is a metal or
earthenware pipe d, d, with which are connected branch pipes e provided
with stop-cocks at their upper parts and leading down into an equal
number of closed vessels f. f, filled with water to about four-fifths of
their capacity. A glazed opening f¹ is provided in each vessel, as shown
in the Drawing, for observing the level of the water, and when it reaches
the line indicated the cock e is turned off. The pipes g, g, serve to
connect the air spaces of the several tanks. The upper part of the first
tank communicates by a pipe h with a fan blower, by means of which
air is first caused to pass through a pipe (not shown) into the furnace a,
thence by elbow pipe 6 through the water in chamber c, from which it
is distributed by pipes d and e through the water in vessels f, finally
returning by pipes g and h to the fan blower after having deposited in
the water the gazeous sulphurous acid which remains in solution and
forms the product to be used for the purposes of this Invention. It will
be observed that the air will only be introduced in such of the vessels f
as are placed in communication with the furnace by opening cocks e,
and the formation of sulphurous acid gas only takes place at such times
as sulphur is being burnt in the furnace. A pipe i extends under the
series of vessels f, which are carried on suitable framework, and are each
placed in communication with pipe i. A cock j is fixed at each end of
pipe for the purpose of quickly drawing off the contents of the vessel c.
The water is supplied to the vessels c from a tank by a pipe k from any
convenient source, in which tank are previously placed the matters
employed, first, for preventing the formation of free sulphuric acid, which
may consist of alkaline chlorides, sulphites, or other matters capable of
saturating the sulphuric acid and not liable to be affected or decomposed
by sulphurous acid; and, secondly, a small quantity of hydrochloric
acid for ensuring the immediate bleaching action of the sulphurous acid.
The addition of these agents for preventing the formation of free
sulphuric acid forms an important feature of the Invention.

page_text: The quantity of alkaline salts to be added would be about two per
cent. (more or less) of the quantity of water employed, and about the
same proportion of hydrochloric acid also would be used, such additions
being made when the sulphurous acid is either in a liquid or gazeous
condition. Although it is possible to completely saturate the water
I prefer that the water be about one-third saturated with the sulphurous
acid gas, the quantity of which latter would in this case be about six per
cent. of the weight of the water.