bleffed, and of which we entertain the highest admiration, without being blindly partial to thofe defects which have crept into its adminiftration. While we confider those as the worst enemies to the happinefs of mankind, who, in pursuit of an Utopian plan of government, which can never be realized, with to fubvert this beautiful political fabric, we cannot regard all in this hateful point of view, who are defirous of a more equal reprefentation in parliament, and of abolifhing thofe venal boroughs, than which nothing can be more inconfiftent with the fpirit of the English constitution. They who affect to apprehend danger to the government from every one who wishes that the abufes, which have crept into it, may be reformed, would do well to confider, that nothing is more likely to produce discontent among a free people, than that extreme jealoufy in government, which prompts it to watch every fentiment of liberty with an invidious vigilance, which deems the common course of the laws infufficient to fupport its prerogatives, and which eagerly embraces every pretence for supplying their fuppofed inefficacy, by temporary expedients. Sow.

ART. IX. Recherches Phyfico-chymiques. i. e. Phyfico-chemical Inquiries. Memoir I. Small Quarto. pp. 40. Amfterdam.

1792.

To purfue chemical experiments with advantage, not only

requires much time and application, but fometimes alfo demands greater pecuniary facrifices than a private individual may think confiftent with prudence. Influenced by these confiderations, and defirous that fuch inquiries may be prosecuted in the manner most likely to extend the limits of science, fix of the most respectable gentlemen in Amfterdam have established a laboratory, under the direction of the ingenious Mefirs. DEIMAN, TROOSTWYK, NIEUWLAND, and BONDT. The memoir before us is the first fruit of their labours; to which they have, with great propriety, prefixed a fhort dedication to the very liberal patrons of their undertaking; these are, HENRY HOPE, THOMAS HOPE, HENRY MUILMAN, PETER MUILMAN, PETER DE SMETH, and WILLIAM SIX, Efquires. We mention the names of thefe gentlemen with the utmost pleasure, as they afford an example highly worthy of imitation; for it is the employment, and not the mere poffeffion, of affluence, that reflects honour or difgrace on the rich; and certainly the promotion of useful knowlege is one of the noblest purposes to which wealth can be applied..

These ingenious chemifts introduce their memoir by remarking, that, though the property of rendering atmospheric

air unfit for refpiration, and of producing a peculiar fetid gas, 'has often been obferved in thofe combinations of fulphur and alcalies, which were formerly called hepars, and which, in the new nomenclature, are termed fulphurets, yet these phenomena have not hitherto been properly connected and explained by a complete theory founded on experiment. This confideration, together with their perfuafion of the utility of a more accurate knowlege of the nature of fulphurets, and of their affinity to water, induced them to make thefe fubftances the fubject of their inquiries.

They firft examined the nature of that affinity between the fulphuret and oxygen, in confequence of which the former effects a decompofition of atmospheric air. For this purpose, they confined equal quantities of dry fulphuret of carbonat of pot-ath in equal volumes of atmospheric air, under two receivers, the one placed over mercury, the other over water. On comparing thefe two volumes of air by the eudiometer, after they had flood during ten days, it was found that the former, which had been placed over mercury, was not more diminished than common air that had been confined during the fame space of time; whereas the latter was fo much decompofed as to be very little diminished by the addition of nitrous gas; fimilar refults occurred on repeating the experiment with barytic fulphuret: but, in both thefe cafes, it was obfervable, that, when the fulphurets were moistened with water, they decompofed the air confined over mercury, as well as that placed over water. The fame phenomena were produced on confining thefe fulphurets with nitrous gas, on which they had no perceptible effect, when perfectly dry: but, when moiftened, they entirely decompofed it, leaving only azotic gas.

From thefe experiments, and from the fulphat† which was formed by expofing water to the action of fulphuret during its production, and before it could come into contact with the atmosphere, the authors explain the affinity between the fulphuret and oxygen, by obferving that, during the formation of the fulphuric acid, or combination of fulphur with oxygen, the alcali prefents a bafe, with which this combination, readily uniting, conftitutes a fulphat. The production of the fulphat is, in this cafe, the effect of two affinities; the one between the fulphur itself and the oxygen, (which, however, does not take place, except in a very high degree of temperature,) and

* Carbonat of pot-afh is the vegetable fixed alcali.

+ Sulphats are vitriolic falts formed by the combination of the vitriolic acid with different bases.

the other, from which the former acquires a greater intensity, between the fulphuric acid and the alcaline bafe:-but the affinity between fulphur and oxygen, though increased by the combination of the former with an alcali, is not rendered sufficiently intense to act on oxygen in its elaftic ftate, for the fulphuret attracts the oxygen, not of the air, but of the water; probably, because, in the latter, it is combined with lefs caloric than in its gazous form. A fimilar phenomenon is obfervable in iron, which, though very little affected by atmofpheric air, or even by the pureft oxygen gas, greedily attracts the oxygen of water.

Thus it appears, that the immediate decompofition in this cafe is that, not of air, but of water; the oxygen of the latter unites with a part of the fulphur, and forms the fulphuric acid, which, by combining with the alcali of the fulphuret, conftitutes a fulphat; while the other principle of the water, or hydrogen, as foon as it is difengaged, and before it can affume a gazous form, unites with another part of the fulphur, and conftitutes that elaftic fluid known by the appellation of fulphurated hydrogen gas. It is obfervable, that hydrogen, in its elaftic ftate, does not readily unite with fulphur, or, at least, that this combination cannot be effected without a very great degree of heat; for though M. Gingembre affirms, that he produced it by means of the fun's rays collected in the focus of a convex lens, the prefent writers could not effect it in a red hot glass tube.

The fulphurated hydrogen gas, thus produced, is fo intimately combined with the fulphuret, that it does not separate from this latter on its folution, but remains united with its alcaline bafe, when this is diffolved in water. Pure hydrogen gas not being foluble in alcalies, it is evident that, to the affinity between the fulphur and the alcali, must be ascribed that which is obferved between the alcali and the fulphurated hydrogen gas, which is fo powerful as to refift the heat even of boiling water, and does not yield, except to an acid; which, in confequence of a stronger elective attraction, faturates the alcali, and thus feparates it from the gas:-but the acids, employed for this purpose, ought to be fuch as do not easily part with their oxygen; for if that be attracted by the fulphurated hydrogen, the acid itself will be decompofed. This is beft prevented by diluting the acid with water.

In the alcaline folution of the fulphurated hydrogen gas, the latter retains its peculiar properties, particularly that of forming water by feparating from the fulphur and combining with oxygen gas: but it must be obferved, that this folution will not take place, unless the alcali itself be diffolved in water.

It may be added, that this property of being abforbed by alcalies, affords a criterion by which fulphurated hydrogen gas. may be diftinguished from the other kinds of inflammable air, as the carbonated and phosphorated, which have not this affinity, and fuggefts an eafy method of feparating it from other fpecies of gas, with which it may happen to be mixed.

On introducing ammoniacal gas into a receiver, placed over mercury, and containing an equal quantity of fulphurated hydrogen gas, the volume of the mixture diminished confiderably, a white vapour arofe, and a blackifh powder was depofited on the surface of the mercury; after standing till the vapour had fubfided, the gas was transfufed into a clean receiver, and placed over pure mercury; diluted fulphuric acid being added to this, the gas was entirely abforbed, which fhewed that it was ammoniacal: but the fame acid being introduced into the receiver in which the mixture had been made, and which now contained only what had been depofited by the vapour, the fulphurated hydrogenous gas was reproduced, and in a volume equal to that which it had filled previously to the mixture.

This experiment illuftrates the affinity between alcalies and fulphurated hydrogen gas, which feems hitherto to have been fo little obferved, that M. Fourcroy, in his Elements of Chemiftry, denies it. It alfo fhews that, when the ammoniacal and fulphurated hydrogen gas unite, they both quit their elastic ftate, and form a fpecies of ammoniacal fulphuret, or, at least, a combination which has this property of a fulphuret, that fulphurated hydrogen gas may be produced from it by the addition of an acid, though not by heat.

From the preceding facts and obfervations, it appears that a folution of an alcaline fulphuret in water may be confidered as refolvable into the three following principles: the fulphuret itfelf, or the combination of fulphur with the alcali; the fulphat, formed by the decompofition of the water, and the union of its oxygen with a part of the fulphur; and, laftly, the fulphurated hydrogen gas diffolved in the alcaline bafe of the fulphuret. It is entirely to the laft of thefe, which abforbs the oxygen gas, that the decompofition of atmospheric air, when confined with an alcaline fulphuret, must be ascribed.

When the folution of the fulphuret in water is performed in veffels accurately clofed, the decompofition of the water continues no longer than till its alcaline bafe is faturated with fulphurated hydrogen gas. Thus fulphurets may be preserved,that is, they will not be entirely transformed into fulphats,-in bottles clofely ftopped:-whence it may likewife be concluded, that the decompofition of water by fulphurets, though partly occafioned

003

occafioned by the affinity between the alcali and the fulphuric acid, is alfo promoted by that between the alcali and the fulphurated hydrogen gas; and this may perhaps be ore reafon why fulphurets decompofe water rather than atmospheric air: for if a fluid fulphuret be confined in the latter, the hydrogen attracting the oxygen produces water, while the fulphur, with which the hydrogen had been combined, remains diffolved in the alcali: but the water, thus generated, is afterward decompofed and reproduced alternately, till, at length, the fulphuret is entirely transformed into a fulphat.

Such are the principal facts and obfervations contained in this ingenious and interefing memoir, which we are the more defirous of communicating to our readers, because it is now printed, not for fale, but only to be diftributed among the philofophical friends and correspondents of the authors It will be, or perhaps already is, publifhed in the Journal Physique : but many of our chemical readers may not have an opportunity of confulting that work.

Sow.

ART. X. Verhandelingen raakende den Natuurlyken en Geopenbaarden Godsdienst & ie Prize Diflertations re auve to Natural and Revealed Religion; published by TEYER'S THEOLOGICAL SOCIETY. Vol. XII. 4to. PP 512. Haarlem. 1792. THERE is not, perhaps, in the whole range of theological in

quiry, a queftion of greater importance than that which is difcuffed in the volume before us. With respect to religion, as to every other fubject propofed to the human mind, men are apt to run into extremes, which, however oppofite to each other, are equally injurious to the caufe of truth. Some pious and well-meaning perfons have unfortunately confounded the history of revelation with revelation itself; by too indiscriminate an affertion that the Bible is literally the word of God, every part of which is alike the refult of an immediate divine infpiration, they have expofed Chriftianity to many objections; and have thus, unintentionally, given occafion to the most plaufible reafons for infidelity. Others have deviated into a contrary error, and, by too great a latitude in explaining the words of the facred writers, have given occafion to depreciate the fanctity of their character, and have weakened their authority, both as the hiftorians and as the preachers of the gospel. Truth, as is generally the cafe, feems to lie between the two oppofite extremes; and it was to promote the difcovery of this happy medium, that the truly refpectable directors of TEYLER'S THEOLOGICAL SOCIETY fubmitted the following propofition to the difcuffion of liberal and rational Chriftians: