An Examination of the Chiltenham Mineral Water, by Conradus-Hieronymus Senckenberg; Which May Serve as a Method in General for Examining Mineral Waters

when their Gas is gone, they are found to contain two Sorts of such-like Earths; the one absorbent, fermenting with Acids; and the other fixt, or Talcky: And that this Substance is really Talcky, is confirmed by the digging up of a pretty deal of Talc in the sinking this Well. All the Salts of the medical Waters are more generally alcaline than acid, being of a Martial Nature, impregnated with Sulphur, which gives them a muriatic Taste. We may hence conclude, that this West Ashton Water is a very good Chalybeat Water; and, by Report, more plentiful and more constant all the Year round, than the Well at Holt, which Spring diminishes much at a certain time of the Year; but both seem alike for their Virtues, and physical Use, being both alike Martial. XXI. An Examination of the Chiltenham Mineral Water, by Conradus-Hieronymus Senckenberg; which may serve as a Method in general for examining Mineral Waters. The Water is bright and clear to the Sight, of no Smell, yet of a bitter Taste. To know its constituent Parts, the following Experiments were made; and, first, to try whether there is any alcaline Salt in it. Rhenish Wine was mixt with the Mineral Water. Rhenish Wine is a subtilized Acidum essentiale in a spirituous and oily Liquor: Wherefore an alcaline Salt should have been manifested; but it was unaltered. Distilled Vinegar is a stronger vegetable Acid; but, mixt with the Water, procures no Alteration. *Spiritus Salis*, *Nitri*, and *Vitrioli*, the three strongest and purest mineral Acids, being mixt with the Mineral Water, there was no Change or Precipitation. *Mercurius sublimatus corrosivus*, is a Dissolution of Quicksilver in concentrated Spirit of Salt, which, being dissolved in common distilled Water, manifested not only the volatile, but also the fixed alcaline Salt, in any Liquor, insomuch that it precipitates the Volatiles to a white, and the fixed alcaline Salts to a red Powder; but, mixt with this Water, produced no Precipitation. *Vitriolum Martis* is an acid Salt, intimately mixt with Iron-earth: Being dissolved, and put into another Liquor, it will presently betray the alcaline Salts by precipitating them; but should it find no contrary Salt, then somewhat of the Iron-earth will settle to the Bottom; as is common in dissolving all sorts of Copperas: And so it happened by mixing this Mineral Water with it, when a brown Powder settled, which is the Terra Martialis. All these Experiments shew evidently, that no alcaline Salt is in the said Mineral Water. For, to try whether there is any acid Salt to be found in this Water, the following Mixtures were made: *Aqua Calcis Vivæ*, which contains an Earth impregnated with alcaline Salt, makes a very quick Discovery of an Acid, by Precipitation; but, mixt with this Water, caused no Variation. *Syrupus Violarum*, having a very sensible vegetable Tincture, which, by mixing it with a small Quantity of of any Acid, turns red, and, with an alcaline Salt, green; but, mixt with this Water, keeps its Colour. Oleum Tartari per Deliquium, which is an alcaline Salt, dissolved in Water: And, Spiritus Salis Armoniaci, a volatile alcaline Salt in Water, they being mixt with this Mineral Water, the Mixture grew milky, and a little after a white Precipitate settled. This happens when a fixed or a volatile alcaline Salt meets with a neutral Salt; then they join together, and somewhat of the alcaline Earth falls down. Milk mixt with a Mineral Water, and boiled in equal Proportion, will make a Separation, by meeting with either an acid or alcaline Salt in it, or, by finding of the last Salt, the Mixture will change red; but our Mineral Water may be boiled with it in several Proportions, without any Change or Precipitation. According to these Experiments, there is no acid Salt in this Water. To see whether there is no Iron or Copperas in it, If the Solution of Galls is mixt with any Liquor, and grows black, then it is a Sign of Iron or Copperas; but our Mineral Water, mixt with it, turned a little brownish, because of the Salt in the Water. To know whether there is any Brimstone in a Mineral Water, it is to be inquired with a polished Piece of Silver, which, being put in the Water, will turn black or yellowish; but this did not happen with this Water. To find out the acidum salinum in a Mineral Water, you must mix with it Solutio Argenti, which turns instantly white, and a light Precipitate falls, being the Luna Cornea. A Solution of Saccharum Saturni, mixt with the Water, yields the Magisterium Saturni. All the above-mentioned Experiments certify, that our Mineral Water contains no alcaline nor acid Salt, no Iron, Copperas, or Brimstone: Therefore from the same Experiments it is evident, that the Chiltenham Water consists of a Sal medium fixum vel neutrum, and a dissolvable Terra alcalina vel cretacea, which may be separated. By a Sal medium, is to be understood, a Salt being neither of an alcaline nor an acid Nature; and that will not precipitate any Solution made with such Salts, nor, mixt with the Syrup of Violets, will change its Colour. These neutral Salts have always their Origin from an alcaline and an acid Salt; and, according to the alcaline Salt they meet with, so they are qualified. So we have the Tartarus vitriolatus, consisting of the Sal alcali fixum, and Acidum vitriolicum. The Arcanum duplicatum of the Sal alcali, Salt-petre, and Acidum vitriolicum. The Sal Mirabile Glauberi, consisting of common Salt, and its Terra fluxilis, and an Acidum vitriolicum; but with this Difference, that the Sal Mirabile will soon melt in a Crucible with a gentle Fire; but Tartarus vitriolatus, Arcanum duplicatum, &c. will not melt, even with the strongest Heat, because of the Difference of the Earth in the alcaline Salt, which in the common alcaline Salt is very fixt, but in the common Salt very volatile and fusible. Such a Sal medium as the Sal mirabile, we find in this Mineral Water, yet mixt with some common Salt. As for the Bitterness of this Water, there is no other Reason for it than the Terra Cretacea, which is proved by by the Epsom Salt, where the Terra alcalina Salis communis, joined with the Acidum vitriolicum; and after the same manner in the Sal mirabile, the alcaline Earth causes the bitter Taste. The same may also be found, by mixing Quick-lime with Spirit of Vitriol, and it will produce a very bitter Taste; but the Mixture of Quick-lime with Spirit of Nitre causes a Bitterness which exceeds Gall. One Pound Troy of this Water yields 29 Grains of the said Sal medium, and 3 Grains of the Earth. Remarks by C. M. The Right Honourable the Lord Cadogan had communicated a short Account of these Waters to the Royal Society on April 17, 1735, being a Letter his Lordship had received from Mr. Tho. Dundas, Surgeon to his Lordship's Regiment, dated at Gloucester, March 25, 1735, wherein he gives an Account of some few Experiments he had made on these Waters, which mostly agree with the preceding ones; as that there were no Marks of a Chalybeat Nature in them; nor any Signs of Nitre or Sulphur: But that six Quarts of this Water being distilled very carefully, the Sediment at the Bottom of the Vessel was nothing more than Alum and Sal Gem, to which it owes its purgative Quality. Some of the Salt of this Water, being put into a Solution of Silver, quickly made a Precipitation of the Silver. Mr. Dundas says, that some alcaline Liquors, as Oil of Tartar, Spirit of Sal Ammoniac, &c. being dropt into some of the Water, immediately produced a violent Effervescence; which plainly shews a great Acidity; which he ascribes to the Alum in this Water. M. Senckenberg found no such Effervescence on mixing these two alcaline Liquors with the Water; but only says it grew milky, and a little white Precipitate subsided. I can account for this material Difference no otherwise, than by supposing, that the Acid, which caused the Effervescence in Mr. Dundas's Experiment, was a volatile Gas, which was not quite spent in being carried no farther than Gloucester, but which was quite evaporated and flown away before the Water came into M. Senckenberg's Hands in London: And as to the Alum, M. Senckenberg did not attend to it. "Mr. Dundas thinks these Waters may be of Use in a lax Constitution; when the Humours are of an alcalefcent Nature; but, when acescent, must do Hurt." XXII. An