Imatges de pÓgina

was expelled. The gas collected over mercury was partly absorbed by a solution of caustic soda, and was found to consist, in one experiment, of 0.41 cub. inch. carbonic acid gas, and 0.29 cub. inch. residue (not absorbable by the alkali) in a dry state, (deduction being made for the elasticity of the aqueous vapour,) at 60° therm. and 30" bar. In another experiment, 0.38 cub. inch. carbonic acid gas, and 0.28 cub. inch. residue, were obtained, the mean of which gives, for one pint of the mineral water, (34.659 cub. inch., or 8767.7 grains,) 0.95 cub. inch. carbonic acid gas.

Twelve cub. inch of the mineral water, mixed with a sufficient quantity of diluted sulphuric acid, gave, when boiled till all disengagement of gas had ceased, 0.89 cub. inch, carbonic acid gas; which quantity gives, for one pint, 2.57 cub. inch. Thus one pint of the mineral water was found to contain 0.95 cub. inch. dry carbonic acid gas, at 60° therm. and 30" bar., in a free state, and (2.57 0.95) 1.62 cub. inch. = 0.75787 grains carbonic acid gas, united to the bases: making, for 1000 grains of the mineral water, 0.08609 grains carbonic acid.

prevent any gas from escaping. By the first effect of heat applied to the ball, part of the mineral water, which is afterwards boiled by the steam passing through it, is carried over into the vessel A. Boiling is to be continued till the increase of gas in the measuring tube has perfectly ceased. The advantages which this contrivance offers are-1. That the whole quantity of the mineral water under examination is submitted to continued ebullition, (no part of it being carried over into the measuring tube.) 2. That the quantity of water condensed in the measuring tube is, proportionately, very small. The air of the vessel A is so perfectly expelled, that the apparatus fills almost perfectly, (leaving, perhaps, an airbubble, of the size of a large pin's head,) when the apparatus is allowed to cool, with its tube B plunged into hot water. The cubical contents of the bottle A, with its pipes, are to be deducted from the volume of the gas obtained, and correction to be made, when the air in the bottle was of another temperature or density. In order to empty the little apparatus, when the experiment has been finished, it is best to connect it, when still hot, with its top downwards, to a common pair of bellows, and to drive the water out by a current of air. The air of the lungs is, of course, not proper for that purpose. Besides the little effect which it would have in drying the bottle, it would leave it partly filled with carbonic acid gas. The balls which I make use of, contain from about 7 to 12 cub. inch.; and I obtain from the smaller quantity, when the mineral waters are rich of gas, results which correspond as closely as can be expected, when the experiment is repeated. If the gas, not absorbable by the caustic alkali, is the object of research, I used to fill the little apparatus with pure carbonic acid gas, and collect the gas in the eudiometer itself, into which a solution of caustic potash has been injected before.

The residue, not absorbed by the caustic soda, gave, by détonation over mercury, 18.2 per cent. oxygen in one expe riment in another, 18.6 per cent.; and may be considered as atmospheric air, originally dissolved by the water, and partly decomposed by its protoxide of iron.



II.-56000 grains of the mineral water were mixed with an excess of carbonate of soda, and evaporated to dryness. The residue was perfectly lixiviated with water, till all reaction on the test paper had ceased; and the saline solution was again evaporated, and kept in fusion over a spirit-lamp for some time, in order to decompose the soda-carbonate of magnesia which might have been formed. The fused mass, when dixiviated with boiling water, left some earthy carbonates, which were added to those obtained by the first lixiviation.


by t 11 -117 do III. One-third of the solution obtained in II, when supersaturated with muriatic acid, and precipitated with muriate of barytes, gave 76.394 gr. of sulphate of barytes; making, for 1000 grains of the mineral water, 2.48539 gr., equal to 0.85471 gr. of sulphuric acid*.


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Another third of the solution, supersaturated with nitric acid, and precipitated with nitrate of silver, gave 20.442 gr. of chloride of silver; making, for 1000 gr. of the water, 1.09511 gr., equal to 0.27017 gr. of chlorine.


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The remaining third, being neutralised with muriatic acid, was evaporated to dryness, and re-dissolved in water, in order to try if any silica had been dissolved by the carbonate of soda; which was, however, not the case.

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TV The earthy carbonates obtained in II. weighed, after ignition, 57.757 grainst; 56.8 gr. of which, dissolved in qThe equivalent numbers are computed according to Berzelius's latest experiments and computations. Vide his Annual Report to the Academy of Sciences of Stockholm for 1827. TETROOT 20715b ti toy gniftrit

Wherever the nature of the precipitate allowed it, the filter was burnt, and the weight of its ashes deducted from the weight of the ignited precipitate. When the precipitate was to undergo a further examination, as much as conveniently could be done was taken from the botesque fai

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muriatic acid and evaporated to dryness, left, when first macerated with muriatic acid, and afterwards perfectly lixiviated with water, 2.539 gr. of silica; which quantity, if proportionated to the whole amount of the residue, gives, for 1000 gr. of the water, 0.04610 gr. of silica,

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...VI.The muriatic solution obtained in V. was precipitated by sulphuretted hydrogen. After twenty-four hours, the liquid was strained off from the sulphuret of lead*; and the hydrothioic acid being expelled by boiling, the iron was again oxidised by chlorine. The liquid (a solution of muriate of ammonia being added) was now precipitated in a closed vessel, by ammonia. The precipitate was kept for further examination.

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VII.-Half of the liquid separated from the precipitate in VIwas precipitated by oxalate of potash. The oxalate of lime, when converted into sulphate, weighed 37.720 gr.; which quantity, proportionated to the whole amount of the earthy residue, gives, for 1000 gr. of the water, 1.36984 sulphate of lime, equal to 0.56894 gr. of limeue to (716x0




VIII The liquid separated from the oxalate of lime was precipitated by ammonia and phosphate of ammonia. The ammonia-phosphate of magnesia, after washing with water containing from three to four per cent. of ammoniat, gave, after ignition, 6.139 gr. phosphate of magnesia; which, com

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filter and ignited; then the filter, together with the remainder of the precipitate, was burnt and ignited; and the weight of both portions was separately ascertained.

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The filter containing the sulphuret of lead was burnt, and the ashes (with an addition of carbonate of soda) being reduced before the blowpipe, the fused mass, taken from the charcoal, left, by a careful elutriation, particles of metallic lead in the mortar, which, when collected, amounted to 0.032 gr., [I assume the lead to originate from the pipes or pump used for, the conveying of the water; and although its quantity is very trifling, yet it deserves the attention of the managers of the Pump-room, whether a more proper material for that purpose might not be selected.

When distilled water alone is used for washing, the precipitate begins to dissolve as soon as the saline liquid is strained off, and the washing fluids are precipitated, as well by ammonia as by the saline fluid first separated.

puted for the whole amount of the residue, make, for 1000 gr. of the water, 0.22294 gr., equal to 0.08175 gr. of magnesia.

IX.-55000 grains of the mineral water were evaporated. The residue, dried at a temperature some degrees above 212°, (where, however, a dissipation of muriatic acid already took place,) weighed 114.75 gr. making for 1000 gr. of the water 2.08636 gr. It was afterwards ignited for some time, after all disengagement of muriatic acid had ceased, (in which state it weighed 110.55 gr.,) and then boiled with water and an excess of pure quicklime, in order to decompose a small portion of magnesia salt, which the mass was found to contain. The liquid was strained off when boiling, and the earthy residue on the filter was perfectly lixiviated with boiling water. The fluids obtained were precipitated, first, by muriate of barytes, then by carbonate and oxalate of ammonia. The fluid, when separated from the precipitate, gave, by evaporation and fusion, 26.46 gr. of the chlorides of potassium and sodium, which, when dissolved in water, left 0.15 gr. earthy residue, thus leaving 26.31 gr. of the chlorides for 55000 gr. of the


X.-The solution of the chlorides was mixed with three times of their own weight of per-chloride of platinum, dissolved in water. The mixture was evaporated to dryness, and the residue macerated first with 38 times of its own weight of alcohol, sp. gr. 0.84 at common temperature, (the quantity which I found the crystallized sodio-perchloride of platinum to require for solution at 60° temp.) The alcoholic solution being decanted, the residue was boiled with a new portion of alcohol. The insoluble potassio-perchloride of platinum being separated, washed with alcohol, and dried at 212°, amounted to 6.378 gr. equal to 1.96130 gr. of chloride of potassium, which quantity gives for 1000 gr. of the mineral water 0.03566 gr. equal to 0.02256 gr. of potassa.

The quantity of chloride of sodium obtained from 1000 gr. of the mineral water amounts thus to (26.31-1.9613) 0.44270 gr. equal to 0.23591 gr. 55 of soda.

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XI. The slight precipitate, adhering to the sides of the bottles which the mineral water had been contained in, was dissolved by muriatic acid. The solution diluted with the rest of the mineral water left in the bottles (1535 gr.) was digested on the earthy residue obtained in IX. The acid solution was evaporated to dryness, and re-dissolved in muriatic acid and water. Filtered off from the remaining silica, it was precipitated by ammonia. This precipitate, together with the precipitate obtained in VI. were dissolved in an excess of muriatic acid, and precipitated by bi-carbonate of ammonia. The weight of alumina and peroxide of iron thus obtained from 112535 gr. of the mineral water, was found to be, after ignition, 0.499 gr., 0.459 of which, when dissolved in muriatic acid, and decomposed by caustic soda, left 0.241 peroxide of iron, leaving for the alumina 0.218 gr.

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By proportionating these quantities, we obtain for 1000 gr. of the mineral water 0.00215 gr. of alumina, and 0.00237 gr. of per-oxide of iron, equal to 0.00213 gr. of the protoxide.

Thus, recapitulating the foregoing results, the solid ingredients contained in 1000 gr. of the Bath water amount to

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From which are to be deducted

As the equivalent of oxygen for 0.27017 of
chlorine, leaving













2.10947 gr.

which quantity coincides nearly with 2.08636 gr., the weight of the dry residue obtained from 1000 gr. of the mineral water, which had, however, lost part of its muriatic acid.-(IX.) ·

If we arrange the above ingredients into binary combinations, according to the predominant chemical affini

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