.passing through different shades, it assumes a brownish-black colour, and the heat being increased, it becomes completely black, and whilst exhibiting the phenomena of combustion. The gas does not contain any carbonic acid, and seems to be the new gaseous compound of carbon and sulphur.

The substance remaining when the carbosulphuret has thus been exposed to a red heat is a mixture of a metallic sulphuret and carbon. I have reasons for considering the brown mass before it has been exposed to a red heat, as a new metallic carbosulphuret, either with another kind of carbosulphuret than that which exists in the precipitated substance, or with the same, but in less quantity. The carbosulphuret of mercury shows the same phenomena, except that at a pretty high temperature, a substance is sublimed which resembles cinnabar, and a black scaly mass remains which is charcoal.

The precipitate obtained from sulphate of zinc and the salt of potash consists, when dry, of small greenish-white heavy grains, soluble both in water and alcohol; however, in a much greater quantity in the latter. The alcoholic solution furnishes, when evaporated, white opaque globular masses. When newly precipitated, it is easily decomposed by sulphuric and muriatic acid, and furnishes an oil-like liquid, similar to that which is procured from the hydrocarbosulphate of lime by a similar process. When heated, this compound of zinc is changed into a mass of a pretty intense green colour, which, when an acid is poured on it, gives out with violent effervescence a gaseous compound of sulphuretted hydrogen, and another peculiar gas. Paper, previously moistened with a solution of lead, becomes, when exposed to these gases, on different places spotted blood-red and black; the first being the prevailing colour.

The hydrocarbosulphuric acid is insoluble in water, or at least nearly so; its specific gravity is greater than 1.0. It may easily be procured by pouring a mixture of one part of sulphuric acid and three-fourths of a part of water on the hydrocarbosulphate of potash, and adding, in a few seconds, a great quantity of water. The acid soon collects on the bottom of the vessel as a completely transparent almost colourless oil; it must be quickly washed with water until it ceases to give a precipitate with a solution of muriate of barytes. The acid may almost entirely be freed from water by decantation.

When litmus paper is brought into this acid, it becomes instantly red; if the paper remains exposed to the air, it becomes partially yellow and white. The smell of this acid is com

pletely different from that of sulphuret of carbon; its taste is acid, and strongly astringent. Exposed to the air, it is soon covered with a yellowish-white coating. It is easily inflamed, and when burned, gives out the smell of sulphurous acid. It is decomposed by heat.

It is easily dissolved by a solution of potash in water, which

is thereby neutralized, and the liquid thus prepared has all the properties of an aqueous solution of that salt which has been made from sulphuret of carbon, alcohol, and potash. When water is present, this acid expels carbonic acid from carbonate of potash, carbonate of ammonia, and carbonate of barytes.

When black oxide of copper, red oxide of mercury, or oxide of lead, is thrown into this acid, there is instantly formed a yellow carbosulphuret of copper, white carbosulphuret of mercury, and carbosulphuret of lead. The same substances are formed when a solution of muriate or sulphate of deutoxide of copper, a solution of sublimate or of nitrate of lead is mixed with this acid. When I poured a small quantity of water on hydrocarbosulphuric acid just enough to cover it, and put a small quantity of iodine into the acid, decomposition took place, and after having added a fresh quantity of water, and shaken the mixture, an oillike liquid separated on the bottom of the glass, which seemed to have all the properties of sulphuret of carbon. The liquid which covered it was weak hydriodic acid, which threw down the solution of sublimate of a beautiful red colour, the nitrate of lead of an equally fine yellow colour, and the nitrate of silver of a whitish colour. When a sufficient quantity of iodine is added to an aqueous solution of hydrocarbosulphate of potash, an oil-like liquid is soon separated on the bottom, which likewise seems to be a sulphuret of carbon, and the solution contains hydriodate of potash.

The following remarks may serve as a conclusion :

When a concentrated solution of potash, soda, or ammonia, is added to sulphuret of carbon in a small flask, a white coagulated mass is formed; when, after the flask being well closed and shaken, it is kept quiet for a moment, gas makes its escape with great violence, if the stopper is removed. The same effect takes place when the sulphuret of carbon is mixed with a small quantity of alcohol. The yellowish liquid out of which the salt of potash crystallizes rather slowly contains not a trace of sulphuretted hydrogen, and has in general the properties of a solution of hydrocarbosulphuret, probably mixed with some sulphur, and a peculiar compound of carbon and hydrogen, which certainly is the cause of the colour of the liquid. When the hydrocarbosulphate of potash is thrown down from its solution by ether, the remaining etherial liquid has the same properties as have been just enumerated as belonging to the liquid remaining after the crystallisation of the salt.

When I, some time ago, tried the effects of olefiant gas on chloride of sulphur, a substance was obtained, the smell of which strongly resembled that of the onion. Mercury, through which this air was passed, had the same smell in a great degree, and kept it for several days even in the open air. The same is the case when mercury is used for the above-mentioned decomposition.

If these two substances, with the same onion-like smell, though produced in quite a different way, are really the same, I am inclined to consider the action of chlorine such as that this body combines with all the hydrogen of the olefiant gas, allowing the sulphur and carbon to form a compound; or that it combines only with a certain quantity of hydrogen, while the rest, together with the carbon, combines with sulphur. I obtained the same onion-like smell a short time ago by passing chlorine through a solution of sulphuret of potash in alcohol. In this case, and when chlorine was passed through sulphuret of potash, another interesting decomposition seemed likewise to take place, which, however, I must make the subject of a peculiar set of experiments.

ARTICLE II.

Reply to Mr. Winch. By G. Young, Esq. and J. Bird, Esq.

SIR,

(To the Editor of the Annals of Philosophy.)

Whitby, Aug. 31, 1822. NOT being regular readers of your Annals, we did not know till last week that a letter appeared in your number for May, from the pen of N. J. Winch, Esq. animadverting on some passages in our Geological Survey of the Yorkshire Coast, and complaining that we have travelled out of our road for the purpose of writing strictures on his geological essays.

Having no idea that we had done any injustice to Mr. Winch, or to other writers, whose mistakes we had ventured to correct, we are rather surprised to notice his complaints. In describing the strata of the Yorkshire coast, and their connexion with those of the county of Durham, we could not conceive that we were going out of our way by pointing out the errors of those who had before us; gone on the contrary, we felt it to be a duty which we owed to truth and to the public. This duty we have endeavoured to discharge without any hostile feelings towards our fellow-labourers in the cause of science; and that our remarks on Mr. Winch's statements did not originate in any such feelings, might be inferred from our acknowledging an instance of his politeness, and from our referring our readers to his paper on the Geology of Durham and Northumberland for an account of the magnesian limestone, and the strata that succeed it.-(See our Geol. Survey, p. 166, 170.)

On what ground Mr. Winch could consider our note respecting the organic remains in the limestone at Hartlepool as a reflection on his accuracy, we cannot tell. The most attentive

observers will sometimes overlook interesting phenomena. We have probably made similar mistakes or omissions in our Survey; and if any literary friend shall point them out, we shall feel obliged, rather than offended. The shells in the Hartlepool limestone are not numerous; so that Mr. Winch might collect a hundred specimens containing none; and had our observations been confined to a single quarry, they might have escaped our notice as well as his. We found them, however, not only in quarries, but in the rocks along the shore, and in several stone walls, constructed with materials procured on the spot.

In the second instance quoted by Mr. W. there is no difference between him and us in our description of what is visible, but merely in our opinions respecting what is hypothetical; and he seems to have introduced the passage only for the sake of exposing a blunder of ours, in applying the term basaltic to the dyke near Cullercoats. But if he will read our words over again, he may perceive that the blunder is his own. We applied no such epithet to that dyke; for in comparing it with our basaltic dyke, we merely call it "a similar dyke or vein," as it intersects the strata in a similar way. Its materials form no part of the subject under discussion in the passage referred to, and do not affect our arguments.

Our remarks on the improper use of the term coal basin are produced by Mr. W. as another attack on him, though they are not aimed at any one author in particular; and though, like our observations on dykes, they oppose his statements only in matters of opinion. We do not call in question the accuracy of his sections, but the justness of the inferences which he would deduce from them. We maintain that coal strata are not more subject to undulations and depressions than other strata ; and that where the coal strata form a basin, the strata above, and those below, must, to a certain extent, assume the same shape. Our opinion on this point coincides with that of Mr. Westgarth Forster, whose acquaintance with the coal and lead mines of Northumberland and Durham is at least not inferior to that of Mr. Winch. He remarks, in the new edition of his Treatise on a Section of the Strata, &c p. 13: "A seam, or bed, of coal is a real stratum, which is found to be quite as regular as any of the concomitant strata found in the coal-field, lying above or below the coal; or indeed as any other of the various strata which compose the external crust of our globe."

But the passage which has given most offence to Mr. Winch (and indeed the only one that can with any plausibility be considered as offensive) is that where we allege, that his geological "Observations on the Eastern Part of Yorkshire," are not the result of personal examination, but compiled from "scraps of information collected from others." To those who are unacquainted with this district, and consequently unable to decide on the merits of Mr. Winch's paper, our remark may appear severe;

but such as have carefully examined it, and compared it with Mr. W.'s description, will think with us, that whatever more we might have said in the way of reprehension, we could not well say less. Of the existence of that paper, as Mr. W. might have seen from the note itself, we had no knowledge till within a few days of the time when the note was printed. We were aware, that in 1814 and 1815, Mr. W. collected some information from Mr. Bird and others, concerning the strata of this part of Yorkshire; but knowing, from his own letters, that he was then very imperfectly acquainted with the subject, and never hearing that he had subsequently made any excursions into the district, we could not suppose that he had attempted to write a geological description of it; and, on meeting with the document, we could not but regret that such a paper had found its way into the Transactions of a Society so respectable. Mr. W. it seems, has, at some remote periods, travelled through the district on business, and taken notes; but however frequent his journeys, and however copious his notes, his own paper, independent of what we know otherwise, warrants us to say, that he has not given the district that kind of examination which is necessary for writing a geological description of it. We have, perhaps, traversed the counties of Durham and Northumberland more frequently than he has done our district; yet we are far from supposing ourselves qualified to give, from our own observations, a tolerable account of their geology. We were detracting much less from Mr. W.'s fame, when we intimated that his paper was a compilation from very scanty and incorrect materials, than we should have done, had we supposed it possible for Mr. W. after a personal exami nation, to write a description so confused, so defective, and so inaccurate. We have paid him at least this compliment, that we could not rate his talents so low. Part of the blunders in his paper might indeed be placed to the score of inadvertency or defective memory; such as his describing the red sandstone of the vale of the Tees as "devoid of mica," with which, in most parts where we examined it, it greatly abounds; his stating that the ironstone of the coal measures is the material employed at the alum works in manufacturing Roman cement, whereas that material is obtained in the alum shale, and does not consist of ironstone, but of lias nodules, the nodules containing much iron or pyrites being rejected as unfit for the purpose; and his describing the oolite as cropping out at Filey Head, and stating that "with this material, York Minster and other edifices in the neighbourhood, are constructed." These, and other minor mistakes, might possibly be committed by one who had examined the district. But how could any gentleman who had spent even but a day or two in acquiring only a tolerable idea of the disposition of the strata, have produced such a mass of error and confusion as is found in Mr. W.'s description of our hills? He speaks of Danby Beacon as part of " the northern escarpment