will always form into pangles. This occafioned the falfe "judgment in Lemery, Geefroy, and feveral other French che"mists; who imagined, that all poisonous qualities existed "in fpicular forms: but that is far from truth; because ex"perience has convinced us, that whenever arfenic meets "with the intrails and juices of animals, without any other "mineral contents, it will perfectly diffolve them. Hence it "is neceffary, in a perfon who has been poifoned with arfenic, "that the cadaver fhould be examined before the third or "fourth day; elfe the anfenic-contents cannot be discovered. "But it must be confeffed, when arfenic is mixt with other "mineral contents, it is doubly armed with destroying wea"pons. Therefore, if your Lordship, for the future, fhould "chufe to make ufe of any foreign fpa-waters, I most hum"bly advise it may be of the Pouhon.

"I am yours, &c.

"Diederick Weffel Linden." What fays the elaborate Lucas to this inveftigation? There is no doubt, fays Dr. Linden, of the real existence of fulphurin mi⚫neral waters; because the whole mineral region is replete there• with. In the course of our experiments we have not made it apparent to the senses; except in the thirty-fixth, where we have made it as confpicuous, as if it was rendered corporeal, or • produced in fubftance: nay, really and corporally it is there; < because arfenic is the only magnet for fulphur. Yellow arfenic, whether natural or artificial, cannot exift without a perfect fulphur; that is, 'tis fulphur which conftitutes the very effence of the yellow colour: and you may as certainly 'conclude, from that experiment, that the medicinal rock• water at Llandrinded contains fulphur, as if it was extracted "per fe.

As to its specific gravity, I have fpoken in the 37th experiment; wherein I have affured you, that, tho' variable, yet it is, at all times, fuitable and agreeable to the human • conftitution.

From what has been faid, we may fafely conclude, that "the rock-water of Llandrinded contains ;

1. A very great plenty of æthereal, elastic, volatile mineral spirits.

2. A mineral balfam of the amber kind; which is combined with the before-mentioned volatile fpirits, and the iron mucilage.

6 3. A volatile vitriolic acid.

4. A large and fufficient quantity of ferruginous contents. 4. A perfect fulphur,

6. A neutral purging falt, participating of the nature of $ borax.

7. The common vehicle water.

So that this water is a perfect purgative chalybeate, excellently well impregnated with other falutary mixtures, fo as to become one of the moft fovereign remedies, and fafe ❝ even in the most enfeebled conftitution.'

He says the contents of this water proceed from pyrites, an iron earth, a vitriolic acid, a fulphur, an absorbent earth, and the carbonous foffil or pit coal. He supports his affertions with judicious obfervations and experiments, and boldly affirms (p. 51) that a faline chalybeate water is in no corner of the world to be met with, nay, cannot poffibly exift, unless the rarified damps, at leaft within two miles diftance from a bed of coal, come in fubterraneous paffages, and intervene with the generative matters that constitute fuch a water.

From his analyzation of this water, and experience, he concludes that it is efficacious in diseases of the lax fibre, scorbutic eruptions, weak nerves, afthma, palfy, epilepfy, agues, obftructions of the vifcera, feminal weakness, and diftempers peculiar to the fair fex. He next launches out into a more minute detail and theory of thofe maladies, which is but fuperficial, and in many places perplexed, and concludes the chapter with fome proper cautions. In difeafes that depend not upon a debilitated frame, I fhould be unwilling to recommend this water. Where there is a tenfe fibre; dense, • rich blood; or in conftitutions, that are otherwise diftinguished with the epithets hot, aduft, or bilious; it will certainly prove prejudicial. For as by ftretching the ftring of ta fiddle too much, you will probably break it; fo, from

❝ over

over-bracing the fibres of the human body, dangerous confequences will enfue.

The fame caution is neceffary with regard to age: for it is not a fit medicine at all times, and ftages of life. Let us ⚫ but consider that the longer we live, the fewer blood-veffels we retain in our bodies; and that the fibres become stiff, and lofe in their fpring or force, fo as to be unable, from their too great rigidity, to give fufficient motion to the juices. This ftiftnefs would be increafed by the cohesive contracting 'power of the chalybeate contents. We may therefore con'clude (allowances being made for the difference of temperaments) that this water is utterly to be avoided after 50 or • 60 years of age.

The following chapter contains directions for the medical use of the rock water at Llandrindod, including neceflary preparations for a course of drinking; the manner in which the course ought to be begun, the method of treating any accidental diforder that may happen during the courfe; the neceffary management after the courfe is compleated; and the regulations to be obferved with regard to after-effects or poflible confequences. Thefe directions are in general juft and judicious, (tho' fome of them appear trivial) and may be of use to those valetudinarians who refort to other springs than thofe of Llandrindod.

The fecond book treats of the pump water, which, from a series of experiments, he believes, may contain a fal enixum boracis nativi, perfectly neutral, a fmall quantity of opaque bituminous parts, which, tho' not diffoluble in water, will eafly flux in the fire, æthereal, elastic, volatile, mineral spirits of the nature, of ambergris and mineral oil.

Of what nature and quality, fays he, the volatile, æthereal, elaftic mineral fpirits are in this water, we are informed by experiments the 2d and 3d. And we are indebted for this ambergris bitumen to the fulphur-water, which is contiguous to the faline purging-water. Both have a great affinity to each other; and are feldom or never found without each other. And by experience it is evident, that wherever we dig below, or through the faline fpring, that then the first water or fpring, that fets in below the falt fpring, is moft commonly H 4 'a ful

a fulphureous one, from whence fome matter, continually exhaling, the faline water gathers, and collects it; and thus obtains its æthereal, volatile, elastic, mineral spirit: ♦ nor need we wonder, that they change their nature by the * admixtures with a faline body: for ambergris itself, when its falts are extracted from it, emits no more the pleasing, but the most disagreeable fulphureous fmell: fo that it is entirely • owing to falts, that the fcent or fmell is fo fragrant in this follil. That ambergris is a foffil or mere pitch, is no longer doubted; fince the great Newman proved it to the royal fofciety in London.

In the second chapter of the second book, he examines the nature, existence, and original caufe of the faline pump-water at Llandrindod. He taxes Hoffman with having contradicted, in page 82 of his observations on mineral waters, what he had advanced in page 51; but, in our opinion, Dr. Linden accufes him unjustly. Hoffman, in page 51, fays there are many medicinal fprings that contain a certain falt, which has hitherto no proper name affign'd it, and is of a neutral nature betwixt acid and alkali. And in page 82 he obferves there are medicinal fprings which can neither be reckoned among the acidule, thermæ, nor ftcel waters; but are of their own peculiar nature, and contain a pure neutral bitter purging falt. Now we should be glad to know in what the contradiction confifts: to us, the fecond paffage, far from contradicting, feems to corroborate the first. Indeed, this is one place in which Dr. Linden does not appear to understand himself; for he plunges into a ftrange fubterraneous fermentation of foffils, the gas of which seems to have had an effect upon his intellects. He affirms (page 170) that every mineral has its peculiar falt; and in the very next sentence owns that limeftone, fpar, afbeftos, talc, flate, chalk, &c. with the help of fulphureous damps and acids, conflitute a common efculent falt. In fhort, the investigation of falt is a fubject that feems to have puzzled and perplexed all our modern chymists. Mondic or pyrites (fays our author, page 171) with feawater will break out into a perfect flame; and if fome bituminous matter is mixed therewith, the fiery eruption is greatly facilitated, or fooner excited; and becomes more 6 perfect:

perfect: mondic is alfo promifcuously found amongst coal. The mafters of coal-veffels fhould therefore be prodigiously 'careful to prevent the fea-water from coming to the coal 'they carry; else they may chance to fall a facrifice to the 'fea by the means of the fire.'

The following remark may be of fervice: Whenever there is brine, or water that will make common falt, there is certainly coal through all that zonic. Hence it comes that coal is always found near the fea fhore; (and often at a great distance from the fea fhore, as on Black-heath, Hounflow-heath, and in inland parts of Northumberland and Scotland) for it is impoffible for coal to generate or exift without the help of brine. In Germany we have this thing exemplified; for we have coal no where, but in fuch places where the brine water is feen; and again, never is this briny water without coal. Credat judæus apella. In page 180 he takes occafion to condemn the use of fea-water, to this effect: Since we have ⚫ mentioned the fea-water, the panacea, or fashionable medicine of this prefent age, we cannot pass over it without giving our opinion; and informing our readers, that on analyzing fea-water, there appears fo many crudities, that we conceive it highly detrimental to the human body; and fear the use of it will, in procefs of time, manifeft its pernicious confequences. That there are these crudities the falt-boilers 'can teftify; and in such abundance, that they are obliged, in this coarse mechanical operation, to ufe eggs, or ox-blood ⚫ for a precipitate.' Notwithstanding this ftricture, we must take leave to affirm, that experience contradicts the doctor's hypothesis; and that expert falt-boilers never ufe eggs or blood for a precipitate.

He recommends the pump-water of Llandrinded as an excellent remedy in the fcurvy and tetterous eruptions, the hypochondriac malady, obftructions in the vifcera, the morphew, flow nervous fevers, the leprofy and gravel. After a short theory of thefe difeafes, he directs the patient with regard to the preparatory evacuations, the method to be pursued in the course, the regimen and diet, the removal of fymptoms that may appear during the course, the management after the courfe, the effects that remain after the use of the water, the

fort