Year: 1887

page_text: Late of Application, 9th Dec., 1837
Complete Specification Left, 10th Sept., 1883
Complete Specification Accepted, 12th Oct., 1888
The ferric hydrate is the purifying agent, as it not only combines mechanically
with the impurities in the water, but also, chemically, with all putrid ferments, such as
alkaline sulphides and sulphurretted hydrogen.
In order to make practical use of this invention for household purposes, I propose
to construct a filtering apparatus in such a manner as to enclose ferric hydrate directly

page_text: between two sponges within a suitable case which may be attached to any water
supply. The water passes, first, through one sponge, leaving a part of its impurities
therein. It will next be chemically purified by the layer of ferric hydrate; and,
finally, passes through the second sponge, when it can be drawn off in an absolutely
pure condition for drinking purposes.
Dated this 9th day of December 1887.
Improvements in Filtering Water.
I, EDWARD THEODOR GOTTHILF THORN, Doctor of Philosophy, of Hollandischer
Brook, No. 15, Hamburg, Germany, Chemist, 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 :-
This invention relates to an improved method of, and means for, purifying and
filtering foul water, and rendering it clear and drinkable.
In carrying my invention into effect, 1 subject the water to the action of ferric
chloride, either in solution or incorporated with negative substances such as filtering
paper or layers, or mixed with dry salts; and then add, in chemical proportion,
sodium bicarbonate, calcium carbonate (marble waste), or magnesium carbonate. The
last two ingredients are preferably employed, as they are not soluble in water, and
only dissolve in proportion to the quantity of ferric chloride added. The impurities
contained in the water are entirely absorbed by the ferric hydrate which is precipitated
according to the formula
The ferric hydrate is the purifying agent, as it not only combines mechanically with
the impurities in the water, but also chemically with all putrid ferments, such as
alkaline sulphides, sulphuretted hydrogen, and the like.
In order to make practical use of this invention for household purposes, I propose
to construct a filtering apparatus as illustrated in the accompanying drawing which is
to be taken as part of this specification and read therewith.

page_text: A case, H, attached by means of a tube, F, to any water-supply, contains, enclosed
between two perforated discs, B, D, and two sponges, A, E, a layer, C, of ferric
hydrate. The water first passes through the sponge, E, leaving a part of its impurities
in the latter. It will then be chemically purified by the layer, C, of ferric hydrate,
and after passing through the second sponge, A, can be drawn off through the draw-
off cock, G, in an absolutely pure and pellucid state.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is :-
1. The hereinbefore described composition of matter to be used for the treatment of
muddy undrinkable water in order to render the same pure and drinkable consisting
of ferric hydrate and calcium carbonate or magnesium carbonate employed as
specified.
2. In a filtering apparatus attached by means of a tube to any water supply, the
combination with two sponges of a layer of ferric hydrate, substantially as specified.
Dated this 10th day of September 1888.