Imatges de pÓgina
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mercury is not known. The effect of the fulling-mill on cloths is a very Gmilar operation to the manufacture of felt.

We find we muft ftill 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 sulfureux en gcneral. 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 sufficient importance

of themselves to attract our attention ; but, as one oba ject 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 sufficiently correct to enable them to obtain an accurate knowledge of the real nature of the watèrs 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, so that a more particular notice of this work is peculiarly necessary 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 results 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 smell, taste, specific gravity, 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 exposure 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 precia pitate, which amounts to about forty grains froin fifty pounds of water; the nature of the deposit, containing sulphur, mild lime, and magnefia. APP, Vol. IV. New ARR.

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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 poflibility of employing every chemical body as a reagent, constitute the fixth chapter.' The seven following ones are employed in describing 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, some metallic calces, particularly solutions of arsenic, antimony, mercury, filyer, &c. Many of these chapters contain new facts and discoveries applicable to the analysis of sulphureous waters. Among these are the combustion and solution of the sulphur precipitated from the water, by the nitrous and oxygenated muriatic acids; the means of separating the sulphur, thus precipitated in the form of flocculi; the volatilization of this fulphur, by water heated to 60°; the fulphureous acid formesl by burning this body in the water, by the oxygen of the nitrous and oxygenated muriatic acids; the rapid separation of this combustible body by the oxids of lead, arsenic, and mercury, the manner of separating and obtaining separately the precipitates of a different nature, formed at the same time, by some of these reagents, and particularly by some of the metallic folutions. The effect of these folutions, considered as three classes and bodies, are carefully compared with the phænomena: fone of these, as the sublimated muriats of arlenic and aniimony decompofe the sulphurated hydrogen gas, which mineraliles the water of Enghein, and give at the same time a precipitate through the water: others, as the nitrats of filver and of mereury, furnish fulphures or sulphurated calces mixed with sulfats and muriated metallic salts, because they have the power of decomposing the vitriolic and muriatic falts in the water. The third class of these metallic folutions contain those not decomposed by the water, nor the salts, but effected only by the gas, the corrosive sublimate for inítance, with the green and white vitriols, whose effects are consequently less complicated, and more easily ascertained.

The coniact 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 fifieenth chapter is on those contents which, from their minute

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proportion, are only conspicuous in the concentrated water, reduced to to of its weight. In this water, by means of ammonia and calcareous muriat, the fulfat of magnesia was discovered, not ascertained by the former expertnets.

From a comparison of the different experiments, our authors find, that the waters of Enghein are mineralised by fulphurated hydrogen gas, sulfat of magnesia, sulfat of lime, muriat of magnefia, carbonat of magnesia, and lime rendered soluble by fixed air.

In the experiments to ascertain the quantity of gas, our aụ. thors 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 allumes, when heated to a certain degree: the proportion was also lesened 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 same time. The appearances in distillation 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 distilling 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 observable 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 sulphur, which is the cause of the colour, while the residuum is still more altered, if the evaporation is more rapid. They were therefore obliged to evaporate 300 pints of the water wholly deprived of its sulphur by the contact of the air, in order to ascertain 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 mislead them in the examination of sulphur waters, particularly when the fulphur remains with the fired principles, in the state of sulphurated lime. This earthy sulphur is decomposed by air, is soluble in alcohol, burns in part during the operation, forms the fulphureous and sulphuric 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

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deprived of its sulphur by the contact of the air. 100 pints they found contained 700 cubic inches of hepatic gus, holding 84 grains of sulphur ; 2 drachms 41 grains of fixed air ; 2 drachms 14 grains of Epsom falt; 4 drachms 45 grains of felenite; 24 grains of fea falt; i drachm 8 grains of muriated magnesia; 2 drachms 70 grains of mild calcareous earth; 13 ; grains of aerated magnefia.

In the twenty-second chapter, the incrustations formed on the arch, and the pellicles thrown up to the surface, are described and analysed. They fhow, that sulphur 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 firft 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 sulphureous waters. They have, in general, occurred in our account, and they are only in this chapter collected, so as to be more striking : 'they deserve 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 some of the Englith mineral waters. That at Bath particularly requires an attentive examination, with the new chemical resources in our hands.

Voyage sur le Rhin depuis Mayence, jasqu’a Dusseldorf. 2 Vol.

830. Neuweid. Chez la Societè Typographique. Th *HE banks of the Rhine, diftinguished for the most beau

tiful prospects, 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 intrinsic 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 sufficient importance to induce us to lay them again aside. 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 position. Its university has kept pace with its trade, and it now

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boasts of a great number of men, truly learned, whose minds are enlightened by every kind of science. The Gothic castle of Martinsbourg is still a part of the electoral residence, and there are few buildings whose apartments are more spacious and more commodious. The two large rooms, which form the library, are equally beautiful and elegant: the books are of the fcarceft kinds. Mayence indeed deserves to poflefs the rareft editions, fince Furt was its citizen. The invention is carried by our author_so 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 psalters they

are printed in imitation of the writing. We have called the Bible che 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 seen an edition of Serapion, printed at Venice so 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 themfelves. Their library and their vaults contain the rareft, the most precious manuscripts; and the oldest most exquisitely flavcured wines : 'we may believe our author, when he tells us, that the last are most frequeutly visited. The vaults are probably well regulated, but in the abbey, there is unfortunately 110 place for the MSS. or the books to be properly arranged. The baron Dunwald's garden, with his singular curiosities, and the Prèvotè 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 seem 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 confessedly softened their ferocity, and polished their manners. Schlozzer, in his Universal History, observes, . Boniface, in our eyes, is a deity. This Englishmange under the protection of Pepin,

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