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by, the course of a river. The inclination of the strata, he tells us, is sometimes so regular, that it may be employed to measure the height of the mountain with tolerable exactness.
The next memoir contains the observations on mines of coal inflamed by accident, by the imprudence of the miners, or heat raised by spontaneous fermentation. The author describes several of these, which burn as long as any fael remains. , When a brook has been conducted into the mine, to extinguish the fire, whose heat is very sensible on the surface, it occasions a little eruption, the nature of which we 'now' very well underitand, and fall explain in another part of this article.'
Some Miscellaneous observations 'follow. .,The first is on calces of iron, found in the schistus that lies over coal. They resemble precipitations of that metal by acids, and one, produced by M, Sage, was like the precipitate obtained by the fac. charine, The second relates to the means of making fætid bitumens aromatic: asphaltum, exposed to a trong sun, in a close vessel (we suppose of glass), resembles in its odour benzoin. In the last volume, M. Fougeroux defcribed fulphur found in the rakings near the gate Saint Antoine : the ground was that on which a Naughter-house formerly stood. M. Morand found the same in the ruins of a house fituated near an old sewer.
The aventurine,'in M. Sage's opinion, is a kind of quartz. It is chiefly made up of small grains of this stone, and to it owes its peculiar property, which is found too in fome species of feld-spath. M. Daubenton thinks that the stone, formerly called aventurine, was rather of the latter species.
The Chemical part of this volume is very interesting, and we have often had occasion to hint at it; we must therefore rest on it with unusual care. In the firft article, • On Vegetable Analysis, count de Milli explains the method by which he intends to analyse vegetable substances, and afterwards to extend it to the animal kingdom. There is a candour and generofity in his conduct in explaining the method, which thews that he is more solicitous for the advantage of science than for the honour of discovery. He now only explains his apparatus, and may be followed by chemifts of different nations. We lately, in our review
Fourcroy's Lectures, mentioned how little we were really acquainted with animal substances ; but we recom. mended an attention to the spontaneous changes, and an exa mination of the different paris, rather than to the more violent separation by means of heat: we know that in this field a rich harvest of discovery may be reaped. The count's plan is not, however, very different. 'He employs a lamp furnace, by which he gives the substance to be examined a constant heat, from the temperature of the air to that of boiling water. The degree is known by the number of threads in the wick, which must be near, but not very exactly reach to the truth. In this apparatus the substances underwent the different fermentations;
a part of each, in its different states, is distilled by a given heat; and the products of this heat are separated by properly stopping the distillation. This method has obviously maný ad vantages, and it is said to be even superior to M. Turgot's, by which the volatile principles are separated without any, or, at moft, very little alteration of the remainder.
The memoir, which follows in the historical part, for it must be understood that the order of the memoirs themselves differs, is that of Messrs. Lavoisier and Meunier, on the Decompos fision of Water. In our Fifty-eighth Volume, pages 250 and 414, we gave a distinct and copious account of the labours of Mr. Cavendish and Mr. Watt, who preceded M. Lavoisier in this discovery. We must not now repeat it, but refer to these articles for what has been done in England. They open an extensive prospect, beautifully adorned, and views that Newton never guessed at. M. Lavoisier found that the water arising from the combustion of pure and inflammable air was equal in weight to the airs employed : in this instance he was more successful than Mr. Cavendith; for in his experi. ment four-fifths of the pure air remained. In many other trials something fimilar occurred: when, for instance, filings of steel, mixed with water, were put under a glass, on
furface of mercury, a considerable quantity of inflammable air was produced ; the steel
was increased in weight, and the water diminished in quantity. We need not explain these appearances to chemists, who will immediately see reason to fufpe& that the inflammable air was produced from the water. We shall mention that water is produced in Dr. Priestley's experiment of reviving calces of metals by inflammable air. All the fame effects, though less completely, we are informed follow the reduction of metals in vitriolic acid air.
It is observed, that aerostatic machines, and reflections on the means of supplying them with inflammable air, first suggested the principal experiment of these chemists. We will now own our obligations to them. Water fell by drops from a funnel on a gwo barrel heated red-hot, and kept in that state by a conftant fire; the consequence was, a copious production of inHammable air. The inside of the gun was lined with a black glittering substance, not malleable, which, when reduced to powder, appeared a true martial æthiops. But this was not sufficient: M. Lavoisier wanted to know the weight of the water which was lost in the experiment, that of the inflammable air, and the increase of weight in the gụn barrel. The sum of these ought to be equal to the weight of the water employed. Besides, the external part of the barrel might have been calcined, and they could not be too exact. They then tried to extinguish red-hot metals in water, and to preserve the air ; in this way they found inflammable air produced only by iron and zinc, the only metals which furnish it in solution with acids. A copper tube was therefore used instead of the iron
one, and piećes of iron, weighed with the greateft exactnefs, put into it. When the experiment was tried with these variations, and allowance made for the water which escaped, the weight of inflammable air, added to the increase of the weight of the iron, was exactly equal to that of the water ori. ginally added.
This theory, he observes, explains many important phenomena. Vegetables, nourished with water, breathe vital air; the inflammable part of the water is preserved, and gives colour and inflammability to the plant. We may add, that fickly vegetables are yellow, and these are expressly found to produce phlogisticated air. In burning spirit of wine, ic is observed, that we can collect a greater quantity of water than we lose of fpirit ; that is, if two ounces of spirit are burned, and half an ounce only remains, more than an ounce and half of watermay be collected: This water, our author thinks, arises from the union of pure air, which ferves for the burning, united to the inflammable air of the spirit. We may suppose then, that in the spirituous fermentation of a solution of sugar in water, the vical air, one of the component parts of the water, waiting with the coaly matter (we should call it phlogistic) of the sugar, forms the fixed air, which issues so abundantly from the fermenting matter; while the inflammable air, with the fame principles, forms fpirit. In fact, we find that spirit of wine in burning, and consequently combining with pure air, produces fixed air ; a proof that it contains the same substance which in the lugar contributed to form the same acid.'
We have given these experiments at some length: though we think the conclufions highly probable, fomething is yet necel, fary to be added. Some of the doubts, which might have arisen, are, we think, obviated by Mr. Watt and Mr. Ca. vendith's experiments; but some remain. It is remarkable that cbis inflammable ais appeared only when iron or zinc were cmployed; and as we procure this air from these metals in ocher experiments, ic seems probable that it is rather furnished by the metuls themselves than by the water. It may indeed be alleged that icon has greater attraction to vical air than any other metal, fince it extracts fome portion of this air from the atmosphere; but we have no evidence of the same power in zinc. If we reverse the language, we may allow that they have both a more powerful attraction for fixed air than any other perfect metal, and would consequently be more capable of decomposing water, if one of its component parts was fixed air ; but, as in many inKances, the language rather than the facts differ, we may perhaps with fafety transfer the analogy. Manganese has a more powerful attraction to fixed air than even iron ; black lead probably fill more. We think that experiments with cheie lubKances might contribute to elucidate the fabject.
The hiftorian of the Royal Academy observes, that M. Lavoifier's theory is not generally adopted; yet he adds, that few
chemical theories are founded on more simple or more conclusive experiments. Light and heat, he observes, seem to be neglected in the operation, and these are either combined with water, or separated from the airs by combustion ; fo consequently we mut either ackpowlege that water is formed of these two fluids, minus the quantity of light and heat; or that each of chese fluids is water joined with light and heat. But, as no experiments have been made on this subject, he thinks the balance inclines towards M. Lavoisier.
As it is impoffible to finish this volume without extending our article too far, we shall defer the remainder to a more convenient opportunity.
Memoires Historiques, Politiques & Oeconomiques, sur les Revolutions: Anglaises dans l’Indoftan. Par 7. A. Pallebot. . Svo.
aim at degrading the rank, and lessening the consequence of our country, it is with great pleasure we find ourselves cons fidered as important by foreigners. M. Paillebot affures the public, that the English poffeffions in India are sufficient to change the politics of Europe, and earnestly invites all other nations to join together, and crush the evil in the bud.' This author claims our attention on the subject of the affairs of India, from his long residence in various parts of the coun: try, and the knowlege which his rank and employments there must necessarily have procured. He professes to take things • ab ovo,' but is not always original. In his account of the Bramins, he transcribes from Hollwell, whose name he industrioufly conceals, even in describing an event where he was a great sufferer, and mentioning a mausoleum which he built in confequence of it. The civil history is taken from Orme, the Life of Nadir Shah, and other English authors : we can often discover the particular passages. In the narration of these events, with which the author may be supposed to be personally acquainted, he is very bitter against the English, and attributes much of our success to bribery; but if there be a crime in of. fering a bribe, there is surely a meanness in accepting it.
After making proper allowances for the envy with which he beholds the prosperity of the English in India, and the mani. feft partiality in favour of his own countrymen, these Historical Memoirs may be read with great pleasure, and contain - many important observations. But we must take notice of some absurdities in his account of a late noble general. We fhall extract the passage. • Loaded with the spoils of Asia, he returns to Europe, where, inding no farther scope for his infernal Machiavelism, his genius, recoiling on itfelf, foon becomes a prey to the avenging furies. His imagination, troubled by the reproaches of his conscience, fees nothing but
massacres, prisons, and speetres. Eager to fly from them, to fly from himself, he goes from England to France, runs from France to Italy, returns to England, where the light of the tragedy of Montezuma, represented at Bath, completes his horror, and renders the light of the day horrible. In this affeating prospect of the horrible cruelties committed in Ame. aica by the Spaniards, who conquered it, he recognized his actions and exploits in Afia. The imprecations of Montezuma on the stage seemed to strike him with curses in his box. He starts from it in terror, haftens precipitately to London, orders his carriage for a journey to France, and almost in the same moment seizing a knife from his cabinet &c.'
Though we allow the force and pathos of this description, yet we must observe, that no tragedy of the name of Montea zuma has been represented many years. That of Dryden has been long neglected. There was an opera of that name, but it could not be performed at Bath ; and the artificial distress of an opera finger was never, we believe, fufficient to drive
any man to despair. If our author's information was not better on the affairs of India, much dependence cannot be placed on his accounts.
The following extract from his Prospectus is no improper specimen of his style and manner. Having allowed that the French were the first who aimed at a territorial revenue; that this alarmed the English, and produced the contest which, after the wars in 1755 and 1762, ended in the enormous ema pire established by us on the ruins of the Mogul, he proceeds:
• This formidable Colossus, from the bosom of Asia, threatens Europe, which, by a strange fascination, seems to look on the vast mass with indifference. Is the restless genius, which used to preside over the balance of Europe, enchanted ?-or does it reckon the weight of Asia, in the hands of England, as of no consequence? What ! the contests for the possession of a small province in Italy, Germany, or Flanders, have more than once raised a flame in Europe, which has trembled for its liberty, and cried out against the aspiring prince for his ambition to attain an universal monarchy! and when England engrosses, one after another, the kingdoms of Asia, the nations of Europe, with a listlessness unworthy of their dignity, leave their common rival to run his race, without an obitacle, when their ruin is the prize that it seeks, and which it is almost ready to seize. Shall an age, distinguished by revolutions fo important, pass away without our perceiving those events, which will sender it an object of attention to the eyes of pofterity?
• Let us rouse, for it is time, and guard against the fur, prizes which England prepares, under the veil which the spreads, with anxious concern, over usurpations already com pleted, and others yet in agitation. It is this deceitful veil which I mean to tear in pieces. After having employed twenty-eight years in Afia, observing and oppoling the designs of Vol. LXI. Jan, 1786.