Aquae. Called also solis aguae, badi-qua aqua. Bath waters.

Dr. Cheyne accounts for the heat of this water by the following experiment. If filings of iron and the powder of sulphur, made into a paste with water, are put into a cellar under a cock which drops water gradually and slowly, it will ferment, and the water running from it will be of the same heat and virtue with those of Bath, though not equally pleasant. Tour-nefort observes, "that the filings of iron will grow warm by steeping in common water, but much more so in sea water; and if powdered sulphur is added, the mixture will burn."

Most hot waters seem chiefly to consist of sulphur and iron, and to differ only as the sulphur or the iron predominates; where the sulphur most abounds, they are hotter, more nauseous, and purgative. According to the Experiments of Dr. Bryan Higgins, a Winchester gallon of Bath water contains,

Acidulous gas, besides what is contained in the above earth and iron, twelve ounces measure; and atmospheric air two ounces.

The four principal waters in England that possess any remarkable heat, are those of Bath, Buxton, Bristol, and Matlock. The first of which raises Fahrenheit's thermometer from about one hundred and eight to one hundred and nineteen; the second to about eighty; the third to seventy-six; and the last to sixty-six or sixty-eight .

Dr. Monro, in speaking of these waters, says the highest degree of heat attributed to them by

And that, on evaporation, a gallon has been found to contain of iron 3/37 or 3/38 parts of a grain; of calcareous earth 22 1/2 grains; seleuites 31 1/2 grains; Glauber's salt 25| grains; sea salt 51 1/3 grains; which were mixed with an oily matter, but not more so than is common to all waters. From this and other accounts it appears that the Bath waters are acidulous chalybeates, in which iron and earth are kept suspended by means of aerial acid; and that they are impregnated with a small portion of selenites, sea salt, and muriated magnesia. Indeed these waters were for a long time esteemed to be sulphureous; but certainly they have not a title to that name in the least: they do not affect the colour of silver or metallic solutions, or produce any other effect of water impregnated with sulphur.

It has been doubted whether hydrogen or azotic gas is contained in these waters; and there was some probability that the latter was an active ingredient in them, but its existence has never been properly ascertained. Dr. Gibbes has lately added to their impregnations the siliceous earth. But we are still unable to discover in their contents any ingredient sufficiently active to account for their effects, and must resolve the question in the present state of our knowledge to the minute division of the substances dissolved; perhaps to these waters containing the proximate principles of some active compound. They operate powerfully by urine, and promote perspiration: if drunk quickly, and in large draughts, they sometimes purge; but if taken slowly, and in small quantities, they have an opposite effect. These waters are adapted to weak and exhausted constitutions, to atonic gout, to visceral obstructions, nephritic complaints, and dyspepsia. Externally they relieve in all the complaints for which the more active stimulant power of the balneum is employed. To the young and plethoric they are frequently injurious; and unless some evacuations are premised, often at first disagree, occasioning headach, heat in the hands, drowsiness, and giddiness. The seasons for drinking Bath waters do not greatly differ. In hot dry summers the waters are strongest, but the spring and autumn are preferred, from fashion probably rather than reason.

More than two pints in a day can never be required, which may be drunk at three or four times, a few hours intervening betwixt each portion; and in such chronical diseases as require preparations of iron, the artificial ones may at the same time be used. See Dr. Cheyne's Account of, and Dr. Falconer's Essay on, the Bath Waters; Monro's Treatise on Medical and Pharmaceutical Chemistry.