the discovery of that property of siliceous earth, which enables it, when united with alkalis, to dissolve in water. Our author pretends to have published this fact in the Transactions of the Friends of Natural History at Berlin. We have not the work at hand; but, if our memory do not greatly fail us, it was hinted at, rather than explicitly pointed out. In the following passage our author has fully explained the source of the carbonic acid. It is impossible, except with peculiar and pointed precautions, to have prevented its attracting the acid from the air.

Dr. Black asks, "How and by what means is the siliceous earth dissolved in water?-Is the hot water, of its own accord, possessed of the power of dissolving this earth? or can this be effected only by the means of the intervening alkali ?"-In answering these questions, he does not approve of Bergmann's opinion, that the solvent power of water, assisted by heat, is alone sufficient for this effect. He rather thinks, that the alkali is the efficient cause of this solution, and the heat merely a means of promoting it. In his opinion, a chemical combination of the silex with alkali is always present, when water exerts a dissolving power on the earth; and this idea he supports by the example of the agency of hot aqueous va◄ pours upon glass. The doubt, which might be raised against it, from the disproportion of these two substances to each other in the Icelandic hot springs, he wishes to obviate by stating, that the silex had originally been united in them with a much larger portion of alkali; but that, subsequently to the solution of this compound in water, part of the alkali had again been neutralised by acids, or acid vapours, that combined with the fluid. But there is no necessity for this mode of explanation; as it is manifest, by several facts, that siliceous earth alone, if under favourable circumstances, is soluble in water, without the concomitant aid of alkaline salt.

• Moreover, this opinion, that the silex exists in the above-mentioned springs in a state of chemical solution by soda, seems likewise to have led Dr. Black to presuppose this alkali in those waters in the caustic or pure state, that is, free from carbonic acid; because it is allowed on all hands, that, in this state only, is it capable of effecting this solution. Yet, not to mention that no proof is given of this hypothesis, there occurs no instance in nature, upon which to establish its probability. The very effervescence, that ensued on saturating with acetic acid the saline residue left by the evaporated water, would prove the contrary; unless, indeed, it be objected to this argument, that the alkali had attracted the carbonic acid, during the evaporation of the water.' P. 494.

The siliceous tufa, from the Geyser, is almost wholly silex, with a very little alumine. The noble opal, from Cscherwenitza in Upper Hungary, is a very brilliant stone, but differing very little from rock crystal or black flint, and contains 0.90 of silex and 0.10 of water. The yellow opal is of a simi

lar kind; and the brown red semi-opal differs only in present ing less flint, and a considerable portion of oxyd of iron.

The semi-indurated steatites-the speckstein of Wernerconsists of about 0.60 of flint, and about 0.31 of magnesia, with some other trifling ingredients. The soap-rock, from Cornwall, is very similar in its nature, but contains alumine with the magnesia: the analysis has, however, been already published by our author. The steatites from China, called the Chinese agalmatolite, offers flint, chiefly with alumine. The last must therefore be removed to the aluminous class, and placed with the lithomarga.

M. Klaproth describes some new titanites from Spain, from Aschaffenburg, from Cornwall (called at first menachanite), and from Ohlápián in Transylvania. The two latter, and one of the species from Aschaffenburg, are joined with iron; but they all contain a large proportion of titanium. As this metal seems to be found in many iron ores, these should be carefully examined; and it may appear to be almost as universally dif- · fused as iron itself; and may perhaps, unsuspectedly, influence its properties.

The garnet-shaped ore of manganese is traced in the rocks of Spessart, near Aschaffenburg. It is found in small quantity; and is by no means rich in the metal, containing only 0.35, with as much flint. The native oxyd of tin (the tin-stone) is very rich, exhibiting near 0.78 of metal, and nearly 0.22 of oxygen. This article is an admirable example of dextrous and simple analysis.

Sulphuret of copper, the grey or vitreous copper ore, from Siberia, presents 78.50 of copper, and 18.50 of sulphur, in 100 parts: the variegated copper ore (the purple copper ore of Kirwan) contains also copper and sulphur, but in a less proportion, together with some iron. The malachites, from the Ural mountains, give copper almost pure, combined only with carbonic acid, oxygen, and water.

The bismuthic silver ore, from Swabia, contains 0.15 of silver, united with 0.33 of lead, 0.27 of bismuth, and 0.16 of sulphur, besides a little iron and copper. The antimoniated silver is peculiarly rich, affording generally 0.84 of silver, while the coarser kinds offer 0.76.

The crystallised bright white cobalt ore, from Tunaberg in Sweden, is a beautiful crystal of a metallic brilliancy. It contains 44 of reguline cobalt, 55.50 of reguline arsenic, and .50 of sulphur, in 100 parts. The cobaltic ore of manganese presents, as may be supposed from its appellation, both, metals; but their proportions are not yet accurately ascertained, as the manganese is too closely united to the cobalt. The native sulphat of cobalt, from Herrengrund in Hungary, has been sup

posed to be a sulphat of manganese; but our author's experiments have decided in favour of the former.

Some of the chemical examinations in this second part have already been published; and several of them will be familiar to the reader. The analysis of the terra Australis, or the earth from Sidney Cove, and the detection of Mr. Wedgwood's error, is one of these. The discovery of the uranite is another. The elastic quartz has also been often described; but, as our author's account of it is short and peculiarly expressive, we shall subjoin it. From analysis, it is almost a pure quartz.

On inspecting with a microscope the homogeneous or integrant parts of which this elastic stone is aggregated, and which may be easily separated by compressure or levigation, I found them all alike: that is, they were all flat, longish plates or scales, perfectly clear and pellucid. All their difference consisted in the variety of their outlines; some truncated more sharply; others more obtusely; others longer, but very thin; while others were broader and shorter; but most of them I perceived on one or both sides notably sinuated. I am inclined to think, that the elasticity of this fossil originates solely from the form of its aggregation. For, as may be distinctly seen at the first glance in the entire stone, all those longish lamella are interwoven in one single direction, and implicated in such a manner, that each junction resembles a vertebra, or hinge. With this idea also corresponds the particular kind of the flexibility of the stone, which is not tough or coriaceous. For, if the stone be held upright and shaken, it vibrates with some noise to and fro; but as soon as its agitation is discontinued, its parts conjoin again firmly by a force like a spring. P. 410.

We find also, in the articles formerly published, a chemical examination of the testaceous sulphat of barytes from Frieberg; of the glass stone (hyalite) from Dauphiny; of the chrysoprase, and its concomitant green earth, which is the oxyd of nickel, and not cobalt, as was formerly supposed-a metal that gives a blue tinge; of the Saxon hydrophanes; of the white and green opal; of the menillite and its matrix-the polishing slate of Werner-which are siliceous; of the silicimurite from the Levant, chiefly consisting of flint and magnesia, with the carbonic acid; of the mineral springs of Imnau in Siberia, which afford an acidulous water, slightly purgative, by its impregnation with Epsom salt; of the tin pyrites (native sulphuret of tin); and of the yellow lead ore (molybdat of lead).

Such are the contents of this very laborious-and to the chemist very valuable-volume. Of the translation we cannot speak, as the originals of very few of the memoirs lie before us. The printing is, however, highly incorrect; and though a few errata be pointed out, numerous and important ones are not noticed. They are indeed generally such as the experienced che

mist can rectify with attention, but to the student may be a source of much difficulty and confusion.

ART. XII.-Sermons on various Subjects. By T. Baseley, A. M. Ec. 8vo. 6s. Boards. Cadell and Davies. 1801.

SEVERAL of these sermons might have been as well entitled Philosophical Essays as discourses from the pulpit; and in the former point of view they discover a considerable degree of ingenuity. The 'famous question on liberty and necessity is treated in two separate lectures; from which the hearers must in general have derived very little satisfaction, or they must have been of a very different class from the majority of Christian congregations. Indeed, in the silence of the closet, and with strict attention to the reasoning of the author, we are not always sure that we rightly apprehend the meaning, or perceive completely the distinctions he would draw between his own opinions and those of his opponents on this intricate subject. There is a little inaccuracy in the outset, which might very easily mislead, if not shock, many of the hearers. In discussing this subject* (says the preacher) let us first appeal to natural reason-the great test of moral and divine truth, next to the ever-sacred law of God itself.' Now to us it appears that the last inquiry is the only one of real importance among Christians; and all that belongs to mere natural reason may be well left to the disputers of this world, whose researches, as far as they are true, will, we have no doubt, be found consistent with the dictates of revelation. Besides, we cannot allow natural reason to be the great test of moral and divine truth; nor do we see how such an opinion can be reconciled with the Articles of the church. Reason may be duly exercised in investigating the evidence that a truth has proceeded from God; but then its province is at an end: and if it be allowed that God is the author of the assertion, the province of implicit faith commences; and reason is not to presume to argue from its narrow capacity against the dictates of superior wisdom.

The well-known interpolation in the First Epistle of St. John, chapter V, verse 7, is made the text to one of these discourses; and as the volume is dedicated to the bishop of Lincoln, who has in the strongest terms expressed his conviction. that these very words- For there are three that bear record in heaven; the Father, the Word, and the Holy Ghost; and these three are one'-were not written by the apostle, but have been foisted into the text, we were curious to see in what manner the preacher would, in defiance of his patron, maintain their authenticity. Our curiosity, however, was completely baffled; for the first verse of the Chronicles would just as well have

suited his discourse; and we cannot doubt that the text was the thing least in the preacher's mind. The whole of the sermon is intended to show that the mystery of a doctrine is no argument against the belief of it; and in this there cannot be any dissent among Christians. The controversy, upon the subject of which the spurious text is supposed to be a proof, does not depend on its degree of mystery; but on the question, whether it be revealed or not in the Scriptures? We cannot approve our author's mode of treating the doctrine of the Holy Trinity; for so this discourse is entitled; since it rather tends to unsettle the mind, than to afford a conviction either of its importance or its truth. From the tenor also of the dedication, we should have presumed it impossible that the author was unacquainted with the writings of his patron; and, indeed, had that been the case, we should have conceived it very improbable that a chaplain to the bishop of Lincoln should be unacquainted with the comments of sir I. Newton, Emlyn, Griesbach, Porson, and Marsh, on this evident interpolation; and much more, that he should have placed it, after a perusal of the controversy, at the head of one of his discourses. We had conceived that the text is no longer referred to by any one who has enjoyed the advantages of a liberal education.

ART. XIII.The History of France, civil and military, ecclesiastical, political, literary, commercial, &c. &c. From the Time of its Conquest by Clovis, A. D. 486. By the Rev. Alexander Ranken, one of the Ministers of Glasgow. Vol. I. 8vo. 95. 8vo. 9s. Boards.. Cadell and Davies.

1801.

THIS volume, which is printed in a compact form, extends to the death of Charlemagne, A. D. 814; and is introduced by the following preface.

It is a reasonable curiosity which disposes men to inquire into the origin of nations, but it can seldom be gratified. The events which led to their formation, and attended their early progress, in a rude and dark age, pass unnoticed, or unrecorded. The purest traditions and fullest chronicles of the following ages are so imperfect, as to leave too much room for the errors of prejudice, and the fictions of fancy. Nor have we much reason to regret the obscurity which must consequently rest on these periods of history: we could derive neither much instruction nor entertainment from the desultory and wanton hostilities, and the perpetual and cruel ravages of barbarous tribes.

For this reason I have not attempted to carry the History of France farther back than the conquest of it by Clovis. That æra is the true origin of the French monarchy: the Franks before that time were German tribes, having no other sovereignty than over their