6

XXXIII.

Account of fome Roman Pottery, found at Sandy in Bedfordshire, and at Lincoln, together with a Roman Speculum. · By Governor Pownall.'

Pottery of this very fabrique,' fays the governor in his affectedly Frenchified language, with exactly fimilar mouldings and ornaments, is at this day found in Provence and Languedoc, particularly at Aix and Nifmes; at Vienne in Dauphine; and in many parts of France; as alfo in many parts of Switzerland. This fabrique was usually called the Samian, mentioned by Pliny, xxxv. 46.'-There is as much difference, betwixt the compofition of this fabrique and the home-made pottery of ancient Europe, the grey, black, and brick-red pottery found every where; as between the porcelaine of China, and the common fuyance of Europe.'

In Chester Field at Sandy was dug up, fome years ago, an urn containing bones and afhes, &c. There was in it a hairpin of that fort, called the hafta recurva. This is now loft. But there ftill remains a curious mirrour or fpeculum, which

, I believe, you will find-to be of a mixt metal, copper, filver, and iron.-It is furprifing, that it has preserved its polifh to fo great a degree, after lying buried fo many hundred years.'

XXXIV. Defcription of the Druid Temple lately difcovered on the Top of the Hill near St. Hillary in Jerfey. Communicated by Mr. Molefworth.'

XXXV. Defcription of a Druidical Monument in the Island of Ferfey; in a Letter from the Right Hon. H. S. Conway, Ga *vernor of Fersey.'

(

We have here a double account, three views, and one ground-plan, of a monument in Jersey, which the writers of Both thefe effays denominate a Temple. The prefent temple,' fays the general, remained entirely covered with earth till the fummer 1785; having the appearance of a large barrow or tumulus, in which form I had conftantly feen it when in the ifland. It then happened, that the colonel of the St. Helier's militia wanting to level the ground for the exercise of his corps, the workmen foon ftruck on the ftones, and the temple thus difcovered was afterwards cleared as it now flands. There is no trace of the time, when it was covered up; not improbably in that of the Romans, by the Druids themfelves; to preferve it, as their most facred temple, from the violence of profanation of that people, who frequently perfecuted them,

and

and who certainly had poffeffion of the ifland.' But we beg leave to inform this refpectable officer and scholar, that a temple covered up by Britons to conceal it from the Romans; profaned by thofe, to prevent it being profaned by thefe; and profaned by men, who used it as a temple, to fave it from being profaned by men, who confidered it only as a rude circle of ftones; is fuch a folecifm in antiquarian fpeculation, as refutes itself sufficiently. It is hiftorically falfe too; as the hundreds of British temples in our own iflands, never covered up from the eyes and hands of the Romans; and particularly thofe grand cathedrals of the Druids, the temples of Abury and Stonehenge, boldly looking the Romans in the face, and defying their profanest touch; demonstrate to our very fenfes. And the fact is, that this imaginary temple is nothing more than a BARROW. Such it appears in the views here given. Such the General had always confidered it; it having', he fays, the appearance of a large barrow or tumulus, in which form I had conftantly feen it when in the island.' It only differs from other barrows, in being a circle inftead of a cromlech of large ftones, at the bafe. This forms an ampler chamber for fepulture within; which is very obfervably divided into cells like thofe of a Cromlech, for the burying-places of diftinct perfons; but has one cell directly oppofite to the entrance, and confpicuoufly larger than the reft. All fhews the barrow to have been conftructed for fome confiderable perfonage, the Sovereign of the island probably, and for his family. These were to be fucceffively buried here, in their feveral cells or cromlechs; the earth being accumulated upon each cell, as it was filled. And, what fixes the whole to be a fepulchre at once, there is a fecret paffage to it formed of fide and covering stones, about four feet in height, and narrowing as it approaches the chamber; a road of accefs, for the interment of some more diftant branches of royalty, in the earth already accumulated within. The fuppofed entrance in it,' fays the anonymous author, may be called a fubterraneous paffage, and measures fifteen feet in length;-the infide of the paffage measures five ⚫ feet three inches in breadth, four feet four inches in height, and the firft covering flone three feet in thickness.' Thus do we fweep away an imaginary temple, and substitute a charnel-house in the room of it. Nor was it conftructed at the first reduction of northern Gaul by the Romans. It was the work of a later period, when the Romans had been for a century masters of the island. 'Two medals were found in this temple,' fays the former effayift, one of the Emperor Claudius, and the other fo < worn by time as to render it unintelligible.' The outfide of the entrance too is guarded by apparent cromlechs; the tombftones of inferior perfons, attendant on the royal chamber of

repofe.

repofe. Alfo about fifty yards fouth from the temple, are five places in the form of our graves, mafoned on every fide, but not paved, and lying eaft and weft.' And, as Mr. Fall, in his hiftory of Jerfey, mentions a fingle altar of large dimenfions then ftanding on the jame bill of St. Helier,' by which in all probability he means merely a cromlech, and near it a circle of other ftones, of which there remained but one when he wrote, the reft having been broken to make a wall hard by;' fo this concurs with all, to prove the prefent building no temple, but a fepulchre, and a fepulchre placed adjoining to a temple,

ART. VII. A Comparative View of the Phlogistic and Antiphlogiftic Theories; with Inductions. To which is annexed an Analyfis of the Human Calculus, with Obfervations on its Origin, &c. By William Higgins, of Pembroke College, Oxford. 8vo. 6s. boards, Murray. London, 1789.

THE

HE late fplendid difcoveries in chemistry, while they have enlarged our knowledge of the fubject, have given birth to two oppofite fyftems. The philofophers on the continent, at the head of whom is M. Lavoifier, have produced a theory which furnishes eafy, clear, confiftent, and elegant explanations of the various phenomena. At the fame time, they do not propofe it as abfolutely complete; they introduce alterations or improvements according as the progrefs of discovery fuggefts. The adherents of the ancient fyftem labour hard to fupport the mouldering fabric. Many important points have been given up, many have been adopted, the theory has been variously moulded, and now little feems to be retained but the name. Mr. Higgins enters the lifts with the ardour of a youthful champion. His views are fanguine, his ideas bold and ingenious. He has collected facts that are numerous and important, he has added feveral new experiments to the general ftock, and has contrafted the different merits of the oppofite fyftems with fuccefs. His affertions indeed are often bold, and his arrangement fometimes obfcure; but the warmth of novelty, and the controverfial nature of the fubject, form a fufficient apology.

Mr. Higgins's experiments ferve to difprove the conclufion drawn by Dr. Pricftley from the inflammation of the oxygenous and hydrogenous gafes. The minute portion of acid is merely adventitious, and water is the real product. Vitriolic acid contains no carbonic gas as its acidifying principle; it confifts of oxygenous and fulphureous acid; for pure alum, heated to ignition, yields thefe products. If iron be diffolved in concentrated vitriolic acid, it abforbs the oxygen and renders it volatile. If

the

the acid be diluted, the water is decompofed, and the hydrogenous gas is given out. When fteam is paffed over fufed ful phur, the oxygen unites with the fulphur, and forms vitriolic acid, while the hydrogenous gas is extricated. Mr. Higgins thus ftates the effects of oils upon vitriolic acid:

Vitriolic acid, poured in fmall proportion on a large quantity of oil, will turn it to a darkish brown colour. This expofed to heat will yield fixable air and volatile vitriolic acid, with a fmall quantity of phlogisticated and heavy inflammable air; and, if the charge be urged with a tolerable ftrong heat, a fmall quantity of fulphur may be produced. Hence we may infer, that the acid is only deprived of a portion of its dephlogisticated air. Animal and vegetable inflammable bodies have certainly stronger affinity to dephlogisticated air than iron has, though they will not readily unite under any circumftance below the temperature of ignition. Oils, animal or vegetable, provided they be free from volatile alkali, will not mix or unite with water in a common temperature, but when diffufed with it by agitation will affume a globular figure, and inftantly feparate from it again on ftanding here the repulfive force between oil and water is evident. If oil and water be boiled under the common preffure of the atmosphere, no decompofition will take place; but if water be gradually dropped into boiling hot oil, inflammable air will be produced, as has been first observed by Mr. Lavoifier. The joint action of air and water can have no great effect on these, and if any at all, it must be in a great length of time. Suet and butter are not decompofed by water alone; for I can affirm that I have been prefent when a fmall tub of butter had been taken from under ground at least three feet deep, and which, from the fituation of the foil and the decay of the wood, must have lain there for upwards of fifty years. It was furrounded with water, for it lay in a marthy foil. It had a difagreeable tafte, and a fpongy white appearance, but did not feem much changed in its chemical properties.'

M. Gengembre fhewed that hepatic gas was hydrogenous gas in which fulphur is fufpended. Dr. Auftin has confirmed this theory by feveral ingenious experiments. He precipitated the fulphur by paffing an electric fpark repeatedly through hepatic gas. He fufed fulphur in hydrogenous gas, azotic gas, and heavy inflammable air,' or a mixture of hydrogenous and azotic gafes. The two former were not in the leaft altered, but the Latter afforded its original bulk of hepatic gas. Mr. Higgins combined hepatic gas with the oxygenous, and found the refiduum was fulphureous acid.-Mr. Kirwan's theory of nitrous acid is clumfy and complicated. The hypothefis of the acidifying principle derived from the carbonic gas is inconfiftent with the experiments of Mr. Higgins and Mr. Cavendish. That carbonic gas is compofed of charcoal and oxygen, and that nitrous acid is formed from oxygenous and azotic gafes, is confirmed by the following experiment of Mr. Higgins:

• I fufed

• I fufed a quantity of nitre in a small earthen tubulated retort, whofe neck was elongated with a glass tube which immerged in water and introduced into it 10,33 gr. of red-hot charcoal, which was expofed to a strong heat for half an hour. It was a whole piece, and the weight was afcertained as foon as it was taken out of the fire. When it got in contact with the fused nitre, a rapid deflagration enfued, attended with a copious extrication of fixable air. When I obtained about 40 cubic inches of air the deflagration ceased, and the charcoal was about confumed. The fixable air was very pure, conaining but 7 cubic inches of phlogisticated air. The difficulty of separating the alkali from the refiduary charcoal without wafte, and the impoffibility of confuming the entire of a quantity of charcoal, as it must be ufed whole in this experiment, render it impracticable to exactly afcertain the quantity of fixable air a given quantity of charcoal would yield; for, as foon as the nitre next the charcoal is decompofed, the procefs ceafes. In order to obviate this inconveniency as much as poffible, I introduced a long and flat piece of charcoal, weighing 10 grains, into a fresh charge of nitre; and, as foon as the deflagration commenced, I kept the charge in continual agitation; which, with the large furface the charcoal itfelf expofed, enabled me to nearly confume the whole. The quantity of charcoal left could not exceed 2 grains. I obtained 80 cubic inches of air, 67 of which were fixed air, and the remainder phlogisticated air.'

Mr. Higgins introduced fome iron filings, recently prepared, into pale nitrous acid largely diluted; the metal robbed the acid of its oxygen, and azotic gas alone was produced. Equal parts of hepatic and nitrous gas, when mixed, contract to of their bulk, and depofit fulphur. Red nitrous acid, exposed to oxygen gas, gradually abforbs it, and becomes colourlefs. The aftonifhing effects of the effufion of oils upon nitrous acid is well known; but even charcoal, if it be very dry, can be inflamed by nitrous acid.

The nature of the marine acid is the least known. It is probable, both from experiment and analogy, that it consists of a certain bafis united to oxygen. But fuch is the volatility of the acid, and fo ftrong its attraction for oxygen, that its bafis has never been separately exhibited. If common falt and litharge be fufed, the acid unites to the lead without fuffering decompofition. Common falt mixed with clay, and exposed to a fierce heat, is in part alkalifed, but afterwards it becomes neutral by exposure to the air. Mr. Higgins infers the compofition of the marine acid from its calcining the metals, and combats with great fuccefs the opinion of fome phlogistians that water unites to form calces. Unlike the other acids, the marine becomes more volatile from the excefs of oxygen; and hence the dephlogisticated muriated acid of Schee!e. If this oxygenated acid be exposed to the light of the fun, it will yield oxygenous gas; and hence it

can