Mineral Waters, include all such fluids as are naturally impregnated with heterogeneous matter, which they have dissolved within the bowels of the earth, whether sulphureous, metallic, or saline; and, as many of these are successfully employed in medicine, they have received the appellation of medicinal waters.
Mineral waters have been divided into hot and cold, from their being either sensibly hotter or colder than the atmosphere. They have also been classed, according to their predominant ingredients, into acidulous, alkaline, martial, sulphureous, etc. It is not, however, our design to enter upon a minute investigation of their constituent parts; but, as the analysis of mineral springs may, to many inquisitive persons, afford a pleasing recreation, independently of its real utility, we shall subjoin a few rules necessary to be observed in making such experiments ; together with a concise account of the waters of Action, and Aix-la-Chapelle, referred to this article on former occasions.
I. All experiments ought to be conducted near the spring, if it be practicable.
II. The situation of such spring, the nature of the soil, and the contiguous rising grounds (if any occur) should be carefully examined.
III. With the view of analyzing the water, it will first be necessary to observe the changes it may spontaneously undergo, as well as the various parts, or matters, into which it may separate. For this purpose, it will be advisable to fill several shallow but large cylindrical glasses at the well, or spring, which should be immediately examined by the taste, eye, and smell: after which they ought to stand at rest for two, three, or more hours, or even as many days. At the end of this period, the. investigation must he repeated ; the fluid compared with water newly drawn from the spring ; and, if any separation of parts take place, any scum arise, or sediment be formed at the bottom of the glass, they ought to be carefully collected for future examination.
IV. These glasses should next be deposited in a warm place ; till, the watery parts being totally exhaled, a dry substance only remains ; which ought to be compared with the sediment obtained from the same water by evapo.a-tion over the fire, in order that the real difference between both dry substances, may be more precisely ascertained.
V. It will next be requisite to analyze the water chemically for this purpose, a certain portion of it ought to be taken from the spring, and poured into a retort with a wide neck, to which a clean glass receiver, well luted, should be affixed. The whole must now be placed over a moderate fire, so as to simmer the water till all the aqueous particles are come over; vhen the vessels should be Buffered to cool, the distilled water carefully drawn off, at d deposited in a well closed glass, : then the dry substance must be separated from the bottom of the retort, weighed, and likewise preserved in a glass.
VI. The distilled water must next be examined by various tests, to ascertain whether it materially differ from distilled common water ; or whether it be impregnated with any saline or mineral particles, similar to those observed in the natural fluid, when first drawn from the well. In this process, if the water contain any common salt, it will, with a solution of silver, assume a white colour : if vitriol of iron be one of its ingredients, it will become black, on being mixed with pulverized galls.
VII. In case the water be suspected to contain any salts, it will be advisable gently to boil a quantity of the dry substance obtained by distillation, in five or six times its weight of pure common distilled water, such as is totally divested of ail mineral particles. By this process, the saline matter will be dissolved or suspended in such water, in the form of a solution, which, on being filtred, and evaporated to dryness, will re-produce its salt. And, if there should be other salts in the same solution, they may all be obtained, by repeating the filtration and evaporation.
VIII. After the different salts are thus evolved, it will perhaps be attended with some difficulty to ascertain those species which are denominated neutral. Tins may be effected by observing the appearances assumed by such salts, on being mixed with other matters. Thus, marine or sea-salt may be known by the white vapour which it emits when in contact with oil of vitriol, and also by its taste, as well as by its cubical figure, on being crystallized. Another distinguishing characteristic of neutral salts is, their property of producing or regenerating sulphur, when mixed and liquefied with salt of tartar, and pulverized charcoal. If, therefore, two parts of such salt be mixed with one part of .sait of tartar, and a similar portion of carbon in powder, and the whole be melted in a crucible, a reddish mass will be formed, possessing an alkaline sulphureous taste, and which will communicate a deep yellow or orange colour to rectified spirit of wine.
Lastly, if there remain any matter, after these various operations have been performed, it is generally denominated an earth, which, by repeated ablutions in pure distilled water, may be divided into various kinds of species, such as calcareous, siliceous, bolar, or ochreous, etc. These may be still farther examined by the test of fire : and, according to the appearances they assume, on bring exposed to that element, it may be easily discovered whether they are vitrescible, or capable of being converted into glass ; whether they will calcine, or become a species of lime; or, whether they will yield any metallic substance.— Such is the method by which the analysis of mineral waters ought to be conducted ; and it is only by a strict observance of the rules above stated, that chemists have been enabled to enrich the world with numerous discoveries in the mineral kingdom.
Acton-water, is a mineral spring of that place, in the county of Middlesex. It is of a whitish colour and sweetish taste, accompanied with a mixture of the bitter found in the Epsom water. Its salt is not so soft as that ob-tained from the latter, though it is more pungent and nitrous, and strikes a deep red or purple, with the tincture of logwood in brandy. It is chiefly used on account of its purgative properties, being little inferior to the Epsom water, of which we have already given an account, vol. ii. p. 232.
Aix-la-Chapelle, or Aken water, takes its rise from several springs in the city of that name. It is remarkable for its sulphureous taste and smell, both which are, by drinking it, communicated to the body. This mineral spring is chiefly employed as a hot-bath; and,from its sulphureous properties, is particularly useful in all cutaneous affections; though, when taken, internally, it is likewise of extensive utility, and possesses considerable medicinal powers. Its sensible effects, indeed, are not very remarkable. In general, it produces a slight degree of gaiety and cheerfulness; but, if drank in too large doses, is apt to produce nausea, vertigo, and sleepiness : if taken in moderation, it proves mildly laxative.
The waters of Aix-la-Chapelle are chiefly resorted to by those who complain of indigestion, and other affections of the stomach, arising from too luxurious living. They are, besides, very efficacious in rheumatism; in hysteric, nervous, and hypochondriacal cases ; in melancholy ; the stone and gravel; in paralysis; and a variety of other disorders.
The proper seasons for drinking these waters are, from the middle of May to the beginning of June; and from the middle of August to the latter end of September. In taking them internally, the patient should commence with half a pint tor a dose, which ought to be increased and repeated more or less frequently, according to the effects it pro-duces, and the intention with which it is used.
As mineral waters frequently contribute to the recovery of health ; and as many persons are prevented from resorting to the place, whence such fluids are obtained, various experiments have been made, with the view of procuring them by art, and communicating to them all the properties of the natural waters. The most complete of such chemi-ral processes appears to be that of M. Goldschmid, who has established a manufactory of factitious waters, at Paris, in imitation of the natural springs of Seltz, Spa, and Sedlitz, which have in all respects been found equal, or superior to those celebrated wells. His preparations have undergone a rigid examination by the ablest chemists, both with respect to their physical properties, and the nature of the salts employed. According to the reports of Buillon-la-Grange, andCHAUSSIER, M. Golds chmid's artificial waters are very clear and transparent, possessing a strong acid flavour, and communicating a deep red shade to the tincture of turnsol. On being placed in contact with various re-agents, these compounds, when mixed with lime-water, produced abundance of carbonate of lime; with caustic alkalies, neutral salts; and, when poured on the filings of the purest iron, they acquired, in a short time, a ferruginous taste,
With respect to the carbonic acid, or fixed air, it appears that the factitious waters contain of it twice and a half of their volume, which is considerably more than the natural springs.
The advantages of these ingenious preparations are stated to be, 1. That they are not liable to be affected by rainy weather, as is the case with the natural water, Which is remarkably influenced by the season. 2. That they do not part with any gas and other volatile constituents, by conveyance, and by keeping them for some length of time; and 3. That the natural fluid can hold in solution only such a proportion of metallic ingredients as the acids and gases contained therein, are capable of dissolving; while the factitious mineral waters are not only cheaper and more efficacious, but retain their virtues without diminution, are impregnated with a larger volume of gas, and may be composed of any quantity and quality of salt or earth, according to particular circumstances. Lastly, they are far more convenient to the purchaser, being much stronger than the natural waters, so that there will be no occasion to drink such large and nauseating doses, as are usually taken of the latter.
With respect to the waters of Bath, Bristol, Buxton, etc. and the principal foreign wells, the reader will find a short account of them, in the progress of the alphabet.