IMPROVEMENTS IN THE PURIFICATION OF WATER, AND THE PREPARATION OF MATERIALS REQIIME BAD MUP PROCESS
Year: 1857

page_text: LETTERS PATENT to Carl Heinrich Julius Wilhem Maximilian Liebmann,
of Fartown, Huddersfield, in the County of York, Warehouseman, for
the Invention of "IMPROVEMENTS IN THE PURIFICATION OF WATER, AND THE
PREPARATION OF MATERIALS REQIIME BAD MUP PROCESS"
PROVISIONAL SPECIFICATION left by the said Carl Heinrich Julius
Wilhem Maximilian Liebmann at the Office of the Commissioners of
Patents, with his Petition, on the 9th March 1857...
I, CARL HEINRICH JULIUS WILHEM MAXIMILIAN LIEBMANN, of 'Fartown,
Huddersfield, in the County of York, Warehouseman, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN THE PURIFICATION OF WATER,
AND THE PREPARATION OF THE MATERIALS. REQUISITE FOR THE PROCESS," to be as
follows:-
A current of carbonic acid is conducted into the water to be purified, and
then a quantity of hydrate of lime (in the shape of either powder or cream)
added,sufficient to producea denseprecipitationand a strong alcaline réaction in
the water. In this state the water has to remain undisturbed till the precipitate
has subsided, and the alcaline water has become clear, or nearly so, then the
water is drawn into a second reservoir by stop-cocks placed right above the layer
of the precipitate. If the original water contains salts of ammonia it is to be
[Price 8d1

page_text: agitated during a short time in this second reservoir by mechanical means of
arbitrary construction or nature. After the expulsion of ammonia, or imme-
diately after the water has left the first reservoir (if ammonia does not exist in
the original water), another current of carbonic acid is conducted into it till
hæmatoxyline added to a sample of it ceases to turn blue. Exactly at that
moment the current of carbonic acid is stopped, and the water must remain
without the slightest agitation. In a few hour's time the precipitate has sub-
sided, and the clear water standing over it is fit for all purposes without or after
its impregnation with'an arbitrary quantity of carbonic acid. This impregnation,
if required, has to take place in another reservoir which contains no precipitate.
The precipitates of the reservoirs are taken out and burnt in retort kilns
exposed to the action of a blowing apparatus, and eventually of an air pump.
The gases evolved by burning are washed to free the carbonic acid from
impurities. If the precipitates contain certain impurities they must be washed
before being burned. Thus the same stock of carbonate of lime is re-employed
many times before renewal. Marching troops, families, or any body requiring
water in smaller quantities, can use bicarbonate of soda and oxalic acid for the
production of cart onic acid, renewing every time the hydrate of lime. The
precipitates may besides replace the bicarbonate of soda.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Carl Heinrich Julius Wilhem Maximilian Liebmann in
the Great Seal Patent Office on the th September 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CARL
HEINRICH JULIUS WILHEM MAXIMILIAN LIEBMANN, of Fartown, Huddersfield
in the County of York, Warehouseman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Ninth day of March, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said Carl Heinrich Julius Wilhem Maximilian Liebmann, Her special licence
that I, the said Carl Heinrich Julius Wilhem Maximilian Liebmann, my
executors, administrators, and assigns, or such others as I, the said Carl
Heinrich Julius Wilhem Maximilian Liebmann, my executors, administrators,
and assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed, should
and lawfully might make, use,exercise, and vend, within the United Kingdom

page_text: of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN THE PURIFICATION OF WATER, AND THE PRE-
PARATION OF MATERIALS REQUISITE FOR THE PROCESS," upon the condition (amongst
others) that I, the said Carl Heinrich Julius Wilhem Maximilian Liebmann,
my executors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office within
six calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Carl Henrich Julius Wilhem Maximilian
Liebmann, do hereby declare the nature of the said Invention, and in what
mauner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
A. THE PRINCIPLES.
The principles on which this Invention rests are the following :—,
1. The less the amount of solid matter contained in water the more salu-
brious is it, and fit for drinking and industrial purposes.
2. Substances not contained in the human body must not even in traces be
found in waterintended for drinking. Iron and magnesia, although component
parts of our chemical constitution, are likewise objectionable.
3. It is of the greatest importance to free water for drinking as completely
as possible from ammonia, and from any gas, except carbonic acid, oxygen, and
nitrogen.
4. A certain amount of carbonic acid renders water palatable without
impairing its other qualities.
5. It is desirable to impregnate water for drinking with an appropriate
amount of carbonic acid, and any waterworks employing the proposed system,
unless counteracted by the composition of the conducting pipes, will attain this
object; where the latter is the case, the works will save money enough by the
system in question to replace their pipes by enamelled ones.
6. In common water generally, and in river water especially, the amount of
merely suspended organic matter mostly exceeds that of the dissolved. In river
water the inorganic matter in suspension (minute dust particles) often even
outweighs that in solution. Filtration, as experience shows, does not wholly
answer the purpose of freeing water entirely from either of these injurious
substances. Dr. Clark's system of precipitation only purifies water which is
comparatively free from those substances, but water abundant with them

page_text: (especially river water during rainy or stormy weather) retains its suspended
particles, or at least a considerable part of them, notwithstanding Dr. Clark's
process, remaining cloudy, and never completely subsiding. To draw down
the above-mentioned particles (minute plants, animals, and inorganic dust,) as
well as to completely free water from them, a precipitate of considerable
density and a repeated precipitation are required.
7. Most if not all chemical precipitates draw down with them salts held in
solution, although not interested in the precipitating process; repeated pre-
cipitations withdraw very sensible quantities of the salts of sodium and
potassium.
8. Certain kinds of water of a green or brown cast can be deprived of the
colouring matter by the offer of an earthy basis, which causes it to subside,
producing a composition somewhat soluble in water, but which, if precipitated
and left undisturbed at the bottom of the vessel, does not dissolve.
9. Concentrated lime water expels ammonia from its compositions if the
whole mixture is continually agitated during a proportionate time, no raising
of the ordinary temperature being required.
10. Carburetted or sulphuretted hydrogen gases, which are often found in
marsh and well water, can easily be expelled by agitation.
B. THE PROCESS.
Before the proper application of this system, water containing the gases just
mentioned (No. 10) must necessarily be agitated during a period sufficient to
remove them, it being indifferent by what kind of mechanical appliance. But
it is obvious that the character of this is somewhat dependent upon the quantity
of the water to be purified; minor quantities emit their gases, if the vessel is
merely shaken during a few minutes; considerable masses may easily be agitated
by wheels, &c. River water, however, seldom or never carries those injurious
gases, and therefore the said preparatory agitation is not required if water of
that kind is the object.
The second step of the process consists in impregnating the water with
carbonic acid to one-tenth of its volume. Waterworks measure the quantity
of the acid which ascends from one or more pipes at the bottom of the
reservoir by a short and practical method, of which hereafter.
The mouths of the gas pipes are shut up by a cover perforated like a sieve,
compelling the carbonic acid to ascend in minute bubbles; thus the impreg.
nation is easily effected without any considerable loss of gas.
Immediately after the impregnation with carbonic acid a quantity of hydrate
of lime is added to the water, without regard to form, as either powder, cream,

page_text: or lime water.
The quantity of the hydrate of lime must be sufficient to
precipitate all the free carbonic acid, the acid of the bicarbonates originally
contained or formed in the water, and besides, to make the whole bulk of the
latter strongly alkaline; much agitation must be carefully avoided while the
lime is added.
The following instance will show how to arrive at the quantity of lime
required: Suppose six million gallons of water are to be purified, add to
them carbonic acid to the amount of one-tenth of their bulk, vizt, 600,000
gallons =2,726,074 litre. To neutralise one litre of carbonic acid it requires
2-516 grammes of lime; the quantity required for the above-named quantity
of carbonic acid is therefore = 6,858 kilogrammes = 18,374 imperial
standard pounds of burnt lime. To this quantity must be added that cor-
responding to the amount of carbonic acid in the bicarbonates of the water.
Suppose the quantity of these to be 14 grains in a gallon, 567 pounds of lime
are the required mass. Besides, the water is to assume a strongly alkaline
reaction in order to precipitate any amount of metals, magnesia, certain
organic matters held in solution, and to be able to afford a second precipitation
by carbonic acid; to this end 0.164 grammes of lime on the litre will generally
suffice, and this proportion requires 12,021 further pounds of lime; thus,
18,374 +567+ 12,021=30,462 pounds of lime, would be the quantity
proportioned to six million gallons. 30,962 pounds of burnt lime correspond
to 55,289 pounds of carbonate of lime=10.36 cubic yards=279.72 cubic
feet.
After adding the lime the water should remain without the slightest
agitation for from 12 to 16 hours, after which time the precipitate has entirely
subsided. The water is then led off through a system of pipes, the mouths
of which are just above the layer of the precipitate, to a second-reservoir,
containing gas pipes of the same construction as those in the first, which
discharge the carbonic acid. How much of this gas is required to precipitate
the free lime is easily ascertained by the aid of hematoxyline, of which test
more in the last chapter.
The lime having been precipitated by carbonic acid, the water settles and
clears itself within a very short time to a perfect brightness, which far exceeds
the transparency of the best spring water; it is then again transmitted through
a system of pipes inserted over the layer of precipitate into a third receptacle.
It is now fit for use, and may or may not again be impregnated with carbonic
acid by pipes of the same construction as those mentioned above. It is
evident that the said impregnation can only take place where the conducting
pipes are of earthenware or enamelled iron.

page_text: The amount of the carbonic acid may be regulated either by mechanical
means (diameter of the gas pipes, height of pressure), or if the whole bulk
of the water is to be impregnated at once, by the chemical test, of which more
in the article on the tests.
If the water to be cleaned contains any sensible amount of ammonia salts,
their basis (ammonia) must be removed before the second current of carbonic
acid is allowed to enter the second reservoir, which is effected by agitating
the alkaline water in the second reservoir by means of one or two wheels of
proportionate diameter and velocity during more or less than one quarter of
an hour. The ammonia evaporates entirely.
Suppose 0.064 grammes of lime to be required to separate magnesia, iron,
organic matter from their composition, as chlorates, sulphates, &c.,=0.100
grammes of lime on one litre remain for producing the alkalescence; six
million gallons will therefore contain 2,726 kilogrammes of lime=2,141
kilogrammes of carbonic acid=5,736 imperial standard pounds=1,082,954
cubic decametres=3,833,258 cubic feet.
C. THE MATERIALS.
Taking up again the premised case of six million gallons of river water to
be purified, we meet with the following requisites :-
1. Carbonic acid to one-tenth of that volume, being 14,436 pounds, for
producing which 32,810 pounds of carbonate of lime are required.
2. 30,962 pounds of burnt lime. If this is to be produced from carbonate
of lime it would correspond to 55,289 pounds of the latter.
3. 5,736 pounds of carbonic acid to precipitate the free lime in the second
reservoir, if evolved out of carbonate of lime, 13,036 pounds are required.
There are, therefore, wanted (a), the quantity of carbonic acid contained
in 32,810 +13,36 lbs. 45,846 lbs. of carbonate of lime; (b), the quick-
lime contained in 55,2-9 lbs. of carbonate of lime. If, to satisfy the latter
postulate, I burn 55,289 lbs. of carbonate, 2 1,327 lbs. of carbonic acid are
set free. Now, of carbonic acid were postulated, 14,436+5,736=20,172 lbs.,
deducting from the mentioned 24,327 lbs. the 20,172, there would be a
surplus of 4,155 lbs. of carbonic acid sufficient to impregnate the six million
gallons to one thirty-ninth of their volume, a proportion producing a highly
palatable water, agreeable through its hardness, because even soft water
assumes a taste of hardness if impregnated with carbonic acid.
But we have to dispose of a still larger amount of carbonic acid; we may
make the proportion 1-34, as will be evident by the exposition following here-
after. This method, by which a bright, tasteless, pure fluid is produced out

page_text: of the most contaminated water of rivers, lakes, and even ditches and marshes,
which removes effectually all microscopic plants and animals, as well as
particles of clay and sand, which finally expels magnesia, iron, ammonia, and
other inorganic component parts of ordinary water, and which held good in
all trials upon Thames water taken at London and Blackfriars bridges,-this
method would be utterly wo: thless if waterworks furnishing a daily supply of
six million gallons were to purchase daily the quantity of 55,289 lbs. (279-72
cubic feet) of carbonate of lime, and to be encumbered with the sale of the
precipitates as manure or whiting. But, as the following explanation will show,
this is not requisite: -Burn the precipitate as you burnt the natural carbonate
of lime (chalk, limestone) to get carbonic acid and quick-lime. None of the
precipitated organic matter will disturb the process of burning, nor will the
inorganic matter do so either. You then may operate by the same stock of
carbonate of lime a considerable length of time, and if you submit to all and
every rule of the system, if you wash the precipitates after a certain period, you
may employ the same stock of limestone for many years. The above explained
process requires only carbonic acid and quick-lime; it operates by uniting
them; separate them again by fire, and they yield over and over again the
two elements in demand.
It is evident that the burning of the precipitates cannot be done in an
ordinary kiln, where the whole amount of carbonic acid escapes; it is, more--
over, doubtless that the said process cannot be realised in retorts of ordinary
construction; the carbonic acid would not leave the lime, but stick to it, and,
besides, the precipitated organic matter would complicate the process, disturb
it, and diminish the quantity of carbonic acid by reduction. The precipitate
must therefore be burnt under the action of a blowing apparatus, answering
the double purpose of, firstly furnishing oxygen to the carbon of the organic
matter, in order to prevent reduction of carbonic acid; and, secondly, of
carrying away the freed acid gas. It is quite immaterial what sort of blowing
apparatus is set in motion if only a sufficient quantity of oxygen is furnished.
It is necessary to prevent the pulverised precipitate from being carried away
with the gas by the current of the blowing apparatus, which can be effected
by a screen at the mouth of the flowing-off pipes. Size and form of the
retorts (earthenware or thin tile or iron cases) is quite arbitrary; the thinner
they are walled the greater of course is the saving of fuel and of time
required for burning, which also diminishes in proportion to the velocity and
power of the blowing apparatus.
The quantity of the organic matter contained in impure water varying

page_text: considerably, it is necessary to ascertain the largest average quantity of
organic carbon found in the water to be purified or in the precipitates, and to
adjust the blowing apparatus accordingly. An excess of this proportion in
favor of the oxygen added will scarcely increase the expense and insure
certain success. The capacity of the retorts is entirely arbitrary; one day's
precipitates may be equivalent to it. As it requires some time to empty the
reservoirs, to wash the precipitates, to fill and empty the retorts, to cool the
quick-lime, &c., the same materials used one day cannot be used again the
next, and therefore three or four times the quantity of chalk or limestone
sufficient for one day's service must be purchased.
In all the above calculations it was premised that the carbonate of lime
was always a pure composition of lime and carbonic acid to simplify the
calculations; but as this is never the case, the above-mentioned quantities
must be augmented in proportion to the impurities of the lime. The purer
the materials the more recommendable they are.
Although immense quantities of carbonic acid in gas form are required it
is not necessary to have any gasholder, as the gas may be cooled within the
conducting pipes by coiling them in a cooling medium (the soil or water), and
letting it out in the reservoirs while it evolves. But to insure perfect order
and regularity in the process, one gasholder of moderate dimensions to hold
the gas not in immediate use would be sufficient.
The gas produced in and flowing from the retorts is not pure carbonic acid,
but contains (besides other components) water and atmospheric air, both of
which are indifferent to this process; but the co-existence of organic matter
in the precipitates could, in spite of the action of the blowing apparatus,
possibly contaminate the gas with other gases, viz, ammonia, sulphureous
acid, carburetted hydrogen, oxyde of carbon, &c. It is therefore important
that the gas is washed before entering the water which is to be purified. This
may generally be effected by pure water, or by the easy and cheap expedient
of an interpolation of chlorate of copper, of peroxide of lead, and other
washing substances, through which the gas
has to pass.
The quick-lime remaining in the retorts after burning the precipitates is not
pure either it contains magnesia, iron, manganese, sulphate or phosphate of
lime, all of which are indifferent, with the exception of sulphate of lime,
which being soluble in water, might, if in excess, impart to the water a pro-
portionate quantity. To prevent such contamination, and to deliver the
precipitates of the alkaline salts which subside at each precipitation with the
carbonate of lime, or if desirable to eliminate the whole or the greater part

page_text: of the organic matter drawn down with the precipitates, the remainder in the
reservoir may be before reburning easily and effectively washed by steam'
power. You have, therefore, to wash either every day, or before every
reburning, or if burning the organic matter is preferable to its expulsion by
water (washing), only as often as the amount of sulphate of lime and other
soluble salts in the precipitates become sensible. River water will on the
average allow seven to ten re-applications of the same stock without washing,
but it is evident that the length of the respective intervals depends entirely
upon the chemical composition of the different sorts of water.
The Inventor of this process used for washing the precipitates an open
plate-shaped basin, sufficient to hold a large quantity of the precipitates, the
produce of one or two days' work; the brim of the vessel is turned outwards,
so as to facilitate the escape of the particles floating on the surface of the
fluid, which fills up the vessel to the brim, or, more properly, over it.
The precipitates having been deposited in this vessel, pure water flows into
it at intervals, either from the mouth of a pipe at its bottom, or from a pipe
leading down perpendicularly to the bottom and in constant motion, the water
running through it to the vessel. In either case the precipitates are repeatedly
putin motion; they float in the water, the formerly suspended organic particles
are set at liberty again, and being of lesser specific gravity than the carbonate
of lime, rise to the surface and flow over the brim with the excess of water,
which at the same time extracts and edulcorates the precipitates of the soluble
salts, and of those chemical compositions of lime and organic matter which
are soluble only in large quantities of water. When a sample of the floating
precipitate shows the depuration realised (see the chapter of tests), the affiux
of water is stopped, and that remaining in the vessel drawn off by a stop-cock
after the precipitate has subsided. This mode of washing scarcely requires
any one's assistance; experience will soon teach the length of time required
for this process, and even make the test superfluous.
It should be mentioned, that in this depuration a loss not exceeding five per
cent. was experienced, and although this may be attributed partly to the
imperfect construction of the apparatus used, a small per-centage of loss seems
inevitable; but this will be repaid by the increase of carbonate of lime at each
repetition of the process, corresponding to the bicarbonate originally contained
in the water. These bicarbonates give an equivalent of their carbonic acid to
the lime of the first reservoir, and fall down as carbonates, thus augmenting
the stock of lime and the carbonic acid.
The above explained cleaning process, as well as the revival of the materials,
demands only a few hands, nor is the apparatus of a costly construction. The

page_text: retorts may be earthenware or iron, the fire-place of plain description, gas-
holders of considerable capacity may be entirely dispensed with, and the
blowing apparatus, the pipes of which go through the, fire ere reaching the
retorts, saves fuel, as it is well known that carbonate of lime emits its carbonic
acid at a lower temperature and more completely if the evolved gas is carried
off after its evolution.
The augmentation of the amount of carbonic acid required in river water is
seldom requisite for well water, but it is imperatively necessary in river, marsh,
and lake water; or else the precipitation, although repeated in the second
reservoir, would scarcely remove all suspended particles, and the water would
remain either cloudy or impure with microscopic beings.
Waterworks operating after this method will always get a bright, crystal,
tasteless water, free from ammonia, from any perceptible amount of organic
matter, from magnesia, metals, deleterious gases, carbonate of lime; and
water companies who send their supply by enamelled pipes may gratify
their consumers by the agreeable addition of carbonic acid without actually
hardening the water.
D. TESTS.
The purifying process above described demands the following tests :-
1, The carbonic acid which impregnates the water of the first reservoir is
to be one tenth of its volume. The quantity of the carbonic acid must there-
fore be ascertained during its afflux to the water, not with the most minute
exactness, but by a speedy method. The following is found most convinient :-
Two gallons of pure concentrated lime water, containing 1 lime in 728 water,
are kept in a bottle, the mouth of which is closed hermetically by an elastic
perforated stopper, to which is fixed a perpendicular glass tube filled with
Graham's mixture of sulphate of sodium and hydrate of lime. If the stopper
is tight the water preserves its concentration without essential change. By a
stop-cock in the lower, not undermost part of the bottle; you draw the water
into a pipette or burette of exact division, and put into a re-agent glass tube a
minute particle of hematoxyline, then pour over it a known quantity of the
reservoir water impregnated with carbonic acid. The hematoxyline does not
colour this water, but the moment after you have added a quantity of lime
water a violet colour appears, which disappears by shaking the glass tube; if
the quantity of lime water is not yet sufficient to precipitate the whole amount
of carbonic acid, you continue pouring out lime water by drops into the water,
which is to be examined, and shake the glass tube after each drop's addition;
the moment the violet colour persists, and does not disappear by agitation, a

page_text: small quantity of lime is already in excess, and all the carbonic acid has been
percipitated. Read then on the scale of the burette or pipette the quantity of
the lime water added, and you know the quantity of carbonic acid contained in
the water, All this may be effected in from three to four minutes. One part
of lime water must be necessary to produce persisting violet colour of 5.4
parts of the reservoir water if 10 per cent. of the volume of the latter is the
amount of the carbonic acid. Now, I postulated the addition of this amount
to the water, which in itself already contains either some free carbonic acid
or bicarbonates; it is necessary, therefore, to ascertain the latter amount by
examination previous to the impregnation with carbonic acid in the same
manner with the aid of hematoxyline and lime water. Suppose the violet
colour becomes stationary at the previous examination after having poured 0.5
into 10-8 of the water, and in the second examination (after the impregnation
of the reservoir water) you have poured out to the same effect 2.5 of lime
water for 10 8 of the other, then the water contained before the impregnation
2.5 per cent. of its volume of free or bicarbonic carbonic acid, and after the
impregnation 12.5 per cent. and you have added the demanded quantity of
the gas, being 10 per cent. Should the most careful accuracy be desirable,
a large quantity of pure lime water may be filled in the bottle above
described, and a measured quantity of it examined after the usual method
of analytical chemistry, then you arrived at the amount of carbonic acid by a
plain calculation; hematoxyline to be used in this case as well. After using
half of the contents of the bottle with lime water, the rest is to be thrown
away and the bottle refilled.
2. The degree of alkalescence in the reservoir water with the addition of
lime is to be ascertained. This is easily done by any acid (muriatic acid has
some advantage over sulphuric acid) of known strength, but hematoxyline is
preferable also in this instance to litmus a.o. Add a particle of hematoxyline
to a measured quantity of water and pour acid of known strength into it by
drops; the moment the violet colour changes to yellow the free lime or its
alkaline equivalent has been saturated. The amount of the free bases is then
ascertained by a simple calculation.
3. The proper time for stopping the afflux of carbonic acid into the second
reservoir (which receives the alkaline water) must be determined. To do
this, the arbitrary quantity of water, however turbid, is poured into a glass
containing a few particles of hematoxyline, and if the slightest degree of
alkalescence still exists in the water a violet colour rapidly appears; the
darker this colour the more distant is the period of saturation in the reservoir.
As soon as the sample discontinues to produce the violet colour the afflux of

page_text: carbonic acid is to discontinue. This test does not prevent an excess of
carbonic acid, because bicarbonates do not produce a violet colour with
hematoxyline; but it is very easy to avoid such excess by a little attention, and
likewise not difficult to correct the water again, by addition of lime water, if
the proper moment has been allowed to pass.
4. To determine the time when the precipitates in the washing apparatus
are sufficiently depurated, and to stop the afflux of water, heat a sample of the
precipitates on a thin platina plate. As long as it turns into a brown or grey
colour it is not in the proner state.
The above explanation presumed always that large quantities of water were
to be purified. In case smaller volumes are to be purified, the carbonic acid
is prepared from bicarbonate of soda, a proportionate quantity of which is put
into a bottle, whose elastic stopper is perforated, and bears a curved glass ora
vulcanised india-rubber tube, covered at the interior end by a piece of thin
muslin, which must always remain several inches above the fluid in the bottle.
The bicarbonate of soda put into the bottle, you pour in some water without
transgressing the necessary distance of the fluid from the end of the glass tube,
(if vulcanised india-rubber should be preferred, some care must be taken to
remove the excess of sulphur,) then you throw into the mixture a propor-
tionate quantity of oxalic acid in crystals. The gas washes itself by passing
the solution of the bicarbonates, the crystals of the oxalic acid subsiding. It
is not necessary to measure the quantity of carbonic acid in the first vessel
accurately; if a sample of the water produce a dense precipitate with lime the
afflux of carbonic acid is to be stopped. Hydrate of lime powder is then
put into the impregnated water, two tablespoonsfull to one gallon, and it is
left to subside. After 10 or 14 hours the bright water above the layer of the
precipitate is let off into another vessel and another current of carbonic acid
conducted into it, the moment for the discontinuance to be ascertained by
hematoxyline. One or two hours suffice to clear the water of this vessel; it is
then drawn into a third vessel, and there impregnated with carbonic acid
arbitrarily.
Earthenware vessels are preferable to any other material, and they may be
so constructed that the substitute for the first reservoir may contain the other
vessel as well as the materials for producing the precipitates, the hematoxyline,
and the glass stop-cocks. Such apparatus is compendious enough to be used
by marching troops, travellers, families, vessels, &c.

page_text: If marsh water is to be purified, the carburetted hydrogen must be removed
before the impregnation by agitating the water with a plain or twirling stick.
The ammonia, found in marshes,bad wells, rivers, and lakes must be eliminated,
by agitating the water in its alkaline state, before inducting the carbonic acid.
In witness whereof, I, the said Carl Heinrich Julius Wilhem Maxi-
milian Liebmann, have hereunto set my hand and seal, this Fifth day
of September, in the year of our Lord One thousand eight hundred
and fifty-seven.
CARL HEINRICH JULIUS WILHEM MAXIMILIAN LIEBMANN. (L,s.)