mercury is not known. The effect of the fulling-mill on cloths is a very fimilar operation to the manufacture of felt. We find we must still defer the seventh volume: the variety of interesting information in this before us has rendered our Article more extensive than we supposed it would have been. Analyse Chymique de l'Eau Sulfureuse d'Enghein, pour servir a l'Histoire des Eaux fulfureux en general. Par M. M. Fourcray & De la Porte, Medecines de la Faculté de Paris, & de la Societé Royale de Medecine. Paris. 8vo. Cachel. THE waters of Enghein are not of fufficient importance of themselves to attract our attention; but, as one object of the Royal Society of Medicine was to obtain a knowledge of the mineral waters of France, and as they found the analyses sent not always fufficiently correct to enable them to obtain an accurate knowledge of the real nature of the waters examined, they directed two of the fellows to publish an analysis of some particular water, as a specimen, In this country, we find the chemists not always acquainted with the subject, or not pursuing the enquiry with scientific accuracy, fo that a more particular notice of this work is peculiarly ne cellary in this kingdom. It is impossible, in a Journal like ours, to point out all the experiments, related with peculiar accuracy, in a work of near 400 pages: it is sufficient to describe the plan pursued, and the new refults from their analysis. They first give an ac count of the situation of the spring of Enghein, or, as they were formerly called, the waters of Montmorency: they next defcribe the labours of their predeceffors in this department, in whom we perceive Macquer, father Cottee, M. M. Vaillard, Roux, and Deyeux. The third chapter contains the physical properties of the water, including its fmell, taste, specific gra vity, limpidity, temperature, &c. In the fourth are the appearances perceived, when the water is heated to different temperatures, for a longer or a shorter period, particularly the time when the hydrogenous, fulphurated gas, feparates at different temperatures. The fifth chapter, the most original of the whole work, contains the phenomena which the waters of Enghein afford by expofure to air, the diminution, and modification of its odour, till it is entirely loft; the precipitates and the pellicles formed on it, the time in which it is completely decomposed, the cause which produces it, viz. the action of the atmospheric oxygen; the quantity of the precipitate, which amounts to about forty grains from fifty pounds of water; the nature of the depofit, containing fulphur, mild lime, and magnefia. APP. VOL. IV. NEW ARR. The general observations on the manner of employing reagents in the great way, on the examination of the precipitates, the choice of the reagents, and on the possibility of employing every chemical body as a reagent, constitute the fixth chapter. The seven following ones are employed in defcribing the actions of colouring materials, of alkalies, acids, faline and earthy neutrals, metals, their calces, metallic solutions, soap alcohol, and many vegetable and animal substances on the waters of Enghein. These are not simple accounts of trials made in the small way, on a few ounces of the water mixed with a few drops of the reagents. The quantities are several pints, and the appearances during the precipitation are described; an analysis of the receptacles formed by each reagent is added, and particularly an examination of those formed by the fulphureous acid, the oxygenated muriatic acid, fome metallic calces, particularly solutions of arsenic, antimony, mercury, filver, &c. Many of these chapters contain new facts and difcoveries applicable to the analysis of fulphureous waters. Among these are the combustion and solution of the fulphur precipitated from the water, by the nitrous and oxygenated muriatic acids; the means of separating the fulphur, thus precipitated in the form of flocculi; the volatilization of this fulphur, by water heated to 60°; the fulphureous acid formed by burning this body in the water, by the oxygen of the nitrous and oxygenated muriatic acids; the rapid feparation of this combustible body by the oxids of lead, arfenic, and mercury; the manner of feparating and obtaining separately the precipitates of a different nature, formed at the fame time, by fome of these reagents, and particularly by some of the metallic folutions. The effect of these solutions, confidered as three classes and bodies, are carefully compared with the phænomena: some of these, as the fublimated muriats of arfenic and antimony decompofe the fulphurated hydrogen gas, which mineralises the water of Enghein, and give at the fame time a precipitate through the water: others, as the nitrats of filver and of mercury, furnish fulphures or fulphurated calces mixed with fulfats and muriated metallic falts, because they have the power of decomposing the vitriolic and muriatic falts in the water. The third class of these metallic solutions contain those not decomposed by the water, nor the falts, but effected only by the gas; the corrofive fublimate for instance, with the green and white vitriols, whose effects are confequently lefs complicated, and more easily afcertained. The contact of the air decomposes the gas; and, in the fourteenth chapter, are the experiments on the water thus decomposed of its air, containing only the neutrals. The fif teenth chapter is on those contents which, from their minute pro 1 proportion, are only confpicuous in the concentrated water, reduced to 많이 of its weight. In this water, by means of ammonia and calcareous muriat, the fulfat of magnesia was discovered, not ascertained by the former expertness. From a comparison of the different experiments, our authors find, that the waters of Enghein are mineralised by fulphurated hydrogen gas, fulfat of magnesia, fulfat of lime, muriat of magnesia, carbonat of magnesia, and lime rendered soluble by fixed air. In the experiments to afcertain the quantity of gas, our authors were often disappointed; for, in the receiver, there was common air enough to decompofe the fulphurated hydrogen, or it was in part decomposed by the heat, discoverable by the brilliant green colour which the water assumes, when heated to a certain degree: the proportion was also lessened by the abforption from the water, or the mercury in the apparatus, and by the mixture of this gas with the fixed air, disengaged at the fame time. The appearances in diftillation are also described. In distilling fix pints of water the gas came over wholly in the first part. In the eighteenth chapter, they carefully describe the appearances observed in diftilling 300 pints of the water; the colour, which becomes at first yellow, afterwards a brilliant beautiful green; the total disappearance of the colours; the light pellicle formed on the surface; the breaking of this pellicle by ebullition; the precipitate which fucceeds, and the faint smell of the water at this period, resembling boiled beans. They remark that the green colour is not obfervable when the water is evaporated in a balneum mariæ, though it appears when the heat is higher; and that the evaporation by ebullition changes the principles, forming an earthy fulphur, which is the cause of the colour, while the refiduum is ftill more altered, if the evaporation is more rapid. They were therefore obliged to evaporate 300 pints of the water wholly deprived of its fulphur by the contact of the air, in order to afcertain exactly the nature and properties of its fixed principles. These details occur particularly in the nineteenth chapter, and are mentioned to guard chemists against the numerous fallacies that may miflead them in the examination of fulphur waters, particularly when the fulphur remains with the fixed principles, in the state of fulphurated lime. This earthy fulphur is decomposed by air, is soluble in alcohol, burns in part during the operation, forms the fulphureous and fulphuric acids, changing the nature and proportion of all the fixed principles in every period of the process. Aware of these difficulties, our authors proceed to examine the fixed refiduum of the Enghein waters, decomposed and Nn2 de deprived of its fulphur by the contact of the air. 100 pints they found contained 700 cubic inches of hepatic gas, holding 84 grains of fulphur; 2 drachms 41 grains of fixed air; 2 drachms 14 grains of Epsom salt; 4 drachms 45 grains of selenite; 24 grains of fea falt; I drachm 8 grains of muriated magnesia; 2 drachms 70 grains of mild calcareous earth; 13 grains of aerated magnesia. In the twenty-fecond chapter, the incrustations formed on the arch, and the pellicles thrown up to the furface, are de scribed and analysed. They show, that fulphur raised in vapours, burns flowly in air, and produces the fulphuric acid formed on the arch of the spring: the fulphur of the pellicles is mixed with äerated lime and magnesia. The first is feparated from the water by the evaporation of the hepatic gas: the second by the evaporation of the fixed air. In the twenty-third chapter, are the new applications which this analysis affords in the examination of fulphureous waters. They have, in general, occurred in our account, and they are only in this chapter collected, so as to be more striking: they deferve the attention of every intelligent chemist. The last chapter treats of the medicinal properties of these waters, and their administration: this we know in general from what we are acquainted with, respecting the virtues of our own fprings at Harrowgate. We must conclude with the fullest and warmest approbation of this work, which we could with to fee imitated by a truly scientific analysis of fome of the English mineral waters. That at Bath particularly requires an attentive examination, with the new chemical resources in our hands. Voyage fur 2. Vol. le Rhin depuis Mayence, jasqu'a Duffeldorf. 800. Neuwcid. Chez la Societe Typographique. THE banks of the Rhine, diftinguished for the most beau tiful profpects, for the most interesting military exploits, celebrated both in literary and civil history, were expected to be again the scene of war; and, when we first took up the volumes, which from their intrinfic merit, we thought deserved fome notice, we had reason to apprehend that the account would be particularly interesting. Circumstances have however changed, and events may be influenced by this change, but they are not of fufficient importance to induce us to lay them again afide. Mayence, our traveller's first object, is a flourishing town: commerce, and its attendant luxury, have introduced improvements and vices. Every happy country cultivates génius, and Mayence is a proof of its polition. Its university has kept pace with its trade, and it now boafts boasts of a great number of men, truly learned, whose minds are enlightened by every kind of science.' The Gothic caftle of Martinfbourg is still a part of the electoral refidence, and there are few buildings whose apartments are more fpacious and more commodious. The two large rooms, which form the library, are equally beautiful and elegant: the books are of the scarcest kinds. Mayence indeed deferves to possess the rareft editions, fince Fust was its citizen. The invention is carried by our author fo far back as 1441. The oldest printed book, the Latin Bible, cannot, however, by any ingenuity be supposed of an earlier date than 1450: more probably it belongs to 1455. A copy of this Bible was in the library of cardinal Mazarin, but it has no date nor place: from many circumstances it appears to be an older book than the pfalters of Mayence in 1457 and 1459 for this reason, that the initial letters in the Bible are written, while in the pfalters they are printed in imitation of the writing. We have called the Bible the first printed book, though, from comparing all the circumstances, the Speculum Sanitatis and Ars Moriendi appear to have been executed earlier. It is well known, that wooden plates were anterior, to moveable types, and these two works are of this class, so that they do not invalidate the opinion. Perhaps the argument of priority, from the initial letters being written, is not of great importance, for we have feen an edition of Serapion, printed at Venice fo early as 1479 in the Gothic character, where the initials are inscribed with a pen. This edition seems to have escaped the attention of De Bure-but we must not wander too far from Mayence. The Benedictines, in this town, are worthy successors of John Fust: they neither forget the cause of literature nor themselves. Their library and their vaults contain the rarest, the most precious manufcripts; and the oldest most exquifitely flavoured wines: we may believe our author, when he tells us, that the last are most frequently visited. The vaults are probably well regulated, but in the abbey, there is unfortunately no place for the MSS. or the books to be properly arranged. The baron Dunwald's garden, with his fingular curiofities, and the Prèvote of Mayence, would detain us too long. The amusements at Mayence are numerous, and the walks highly celebrated: those, however, of the garden La Favourite feem to be too much in the style of the last century. The apostle of this part of Germany was Boniface, an Englishman. He was the first archbishop, and confefsedly foftened their ferocity, and polished their manners. Schlozzer, in his Universal History, observes, 'Boniface, in our eyes, is a deity. This Englishman, under the protection of Pepin, taught |