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Prof. Bunsen visited Krisuvik in 1845: his opinion is that sulphurous acid is evolved from the earth's interior, which, oxidised either at the surface by the atmosphere, or at subterranean depths by atmospheric oxygen dissolved in cold water, is converted into sulphuric acid. The sulphuric acid thus generated is diffused among the constiuents of the decomposed beds. This process represents the first stage of the fumerole action, which is manifested in the namar or solfatara of Krisuvik.

Sulphur is now generally regarded as emanating from the stage of intermittent lethargy of a volcano, and the sulphides of iron, copper, arsenic, zinc, selenium, &c., fall in the same category as sulphur; they are secondary, not primary, formations. In the stage further off we have the host of sulphates produced by the oxidation of the sulphur into sulphuric acid, and its subsequent reaction on the metals and earths with which it becomes associated. The description of the Sicilian sulphur beds coincides so very exactly with that of the Icelandic mines, that one might pass very well for the other. D'Aubigny pictures nearly the whole of the central portion of Sicily as being occupied by a vast bed of blue clay or marl, in which are numerous and thick beds of gypsum and sulphur, and a

mud cauldrons, and geysers are found in all parts of the region, and the description given by Mr. V. Hayden, of the Yellowstone lake and its vicinity, in every respect coincides with those of the geysers, mud cauldrons, and hot springs of Iceland.

In all cases there was found to be free access of water; free sulphur was widely dispersed, and the steam-jets were invariably accompanied by large quantities of sulphuretted hydrogen. The subterranean action in this country does not appear to have continued long enough to produce beds of sulphur and sulphur earths; but has, nevertheless, been of sufficiently long standing to build up geyser tubes of so great a length that the internal pressure has formed other vents, rather than lift the immense column of water above it.

The water of the springs contains sulphuretted hydrogen, lime, soda, alumina, and a slight amount of magnesia; some of these are only occasionally at the boiling-point, and these, when the temperature is reduced below 150° F., deposit great quantities of the sesquioxide of iron, which lines the insides of the funnels, and covers the surface of the ground wherever the water flows. If the reaction consists in the decomposition of iron pyrites, and the sul

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combination of this mineral with iron and copper. The natural process by which they have been formed must, I think, be the same in each case. At Krisuvik copper has been found only in small quantities, but that is probably because it has not been sought for below the surface. Carbonate of copper, associated with sulphate of lime, is of frequent occurrence, and native copper has to a limited extent been discovered.

A district in America, very similar in most of its characteristics, has recently been explored, The great hot-spring region of the sources of the Yellowstone and Missouri rivers, in the United States, has, on account of the wonderful natural phenomena there manifested, been set apart by the United States Congress as a great national park for all time.

The whole of this district is covered with rocks of volcanic origin of comparatively modern date. At present there are no signs of direct volcanic action going on, but the secondary kind of action, resulting probably as at Krisuvik, from the disintegration and decomposition of beds of volcanic origin, is in full progress. Boiling springs,

phur is carried sufficiently far off to prevent its re-combination with the iron to form iron sulphate, the formation of the iron sesquioxide is fully accounted for.

As a rule, the groups of hot springs are, as in Iceland, in the lower valleys, and either along the margins of streams, or nearly on a level with them. The grand area where they occur is within the drainage of the Yellowstone, where a space of 40 miles in length with an average width of 15 miles, is either at the present time, or has been in the past, occupied by hot springs.

That the quantity of sulphuric acid here produced is very large is proved by the immense quantity of alum which is found, for the streams, the mud, the earth are thoroughly impregnated with it. The funnel-shaped craters from which the boiling mud is ejected, are so similar to those at Krisuvik that the figure on page 113 wil answer for both places. The circular rim varies from a few inches to several feet in diameter. Sometimes these are clustered close together, yet each one being separate and distinct from the others.

The foregoing are the most prominent facts connected

with the development of sulphur from the earth in the elementary state. The full explanation of all the phenomena accompanying it appears to me to be the key by which the great secret of volcanic energy may be ultimately unlocked. At present it appears to be doubtful whether the sulphur results from the decomposition of metallic sulphides, by heat and water combined, or by sulphuric acid formed by the oxidation of sulphurous acid. In the one case, the whole action is so far within our reach that it should not be an insurmountable difficulty to establish the point as to whether the whole action does not depend on the percolation of water into beds of pyrites surrounded by other beds which are non-conductors of heat.

The other view, viz., that the sulphur proceeds as sulphurous acid from a lower depth, is, on account of the more complicated action required, far from being as satisfactory to my mind as the more simple supposition above.

Until boring experiments have been made, conducted with great care, and to considerable depths, no positive conclusion can be arrived at. It is also an element in the question of much importance to discover whether the beds penetrated by the water are already heated, whether the water is heated before it reaches the sulphur-bearing strata (the clays containing pyrites), or whether both are not alike cold till they have been for some time in contact. Less than a quarter of a mile from the hot springs is a lake, Geslravatn, formed by the filling up of an extinct crater. This the inhabitants describe as being fathomless (Mr. Seymour, last year, found no bottom at five and twenty fathoms). The depth is, at any rate, very considerable. Although so close to a spot where the ground is, even at the surface, scorching to the feet, the water in this lake is ice-cold. Sir George Mackenzie also remarked a somewhat similar fact. On the side of the sulphur mountain, amidst the seething, steaming hills of almost burning earth, a spring of clear cold water was met with. To my mind these facts are most in accordance with the view that the action is local and self-dependent.

The Krisuvik sulphur mines have been worked at various times, but want of proper roads, and ignorance of the proper method of extracting and refining the sulphur, have prevented their proper development. The Sicilian mines can be worked at a considerable profit, where, more than 390 feet below the surface, beds are met with containing only 15 per cent of sulphur. At Krisuvik, absolutely on the surface, clays are met with which contain from 15 to 90 per cent of sulphur. Under proper and careful supervision their future should be prosperous.

Two German gentlemen, under the auspices of the Danish Government, worked these mines in the early part of the last century, and so much was exported to Copenhagen during the time the excavations were carried on, that a sufficiently large stock was laid up to serve the consumption of Denmark and Norway from 1729 to 1753. Horrebow describes the sulphur mines as being actively worked from 1722 to 1728, to the great advantage of the inhabitants, who reaped much profit from its extraction.

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By his account of their mode of prosecuting this enterprise, the sulphur does not appear to have been refined in the island, but exported in its crude state. The less active mines were chosen for cutting into. He says:-There is always a layer of barren earth upon the sulphur, which is of several colours, white, yellow, green, red, and blue. When this is removed the sulphur earth is discovered, and may be taken up with shovels. By digging 3 feet down the sulphur is found in proper order. They seldom dig deeper, because the place is generally too hot, and requires too much labour, also because sulphur may be had at an easier rate, and in greater plenty, in the proper places. Fourscore horses may be loaded in an hour's time, each horse carrying 250 lbs. weight. The best veins of sulphur are known by a kind of bank or rising in the ground, which is cracked in the middle.

From hence a thick vapour issues, and a greater heat is felt than in any other part. These are the places they choose for digging, and after removing a layer or two of earth, they come to the sulphur, which they find best just under the rising of the ground, when it (the sulphur) looks just like sugar candy. The farther from the middle of the bank the more it crumbles, at last appearing as mere dust. But the middle of the bank is an entire hard lump, and is with difficulty broken through. The brimstone, when first taken out, is so hot that it can hardly be handled, but grows cooler by degrees.

In two or three years these veins are again filled with sulphur. The death of the person at Copenhagen who had the sole and exclusive privilege of exporting sulphur from Iceland put an end to what had promised to be a very thriving industry. The inhabitants continued to collect the sulphur-earth for some time after its exportation had ceased; and many of them lost considerably by it, large quantities having been gathered which they were never able to dispose of.

According to Dr. Perkins, the sulphur mines were again worked by the Danish Government for fifteen years, but the method of purifying adopted was very imperfect. The sulphur-earth was heated in iron boilers, and, when the sulphur was melted, fish oil was added, and the whole mass stirred up. On allowing the mixture to stand for a time, the earthy matter formed a soap on the top of the molten mass; this being removed, tolerably pure sulphur remained behind.

In 1832, these mines were visited by K. von Nidda, the celebrated geologist, by whose advice a Danish merchant, named Kruntynon, purchased them. He only worked them for a short period. The sulphur-earth was collected without much regard being paid to the relative richness of the beds. It was taken on the backs of horses to Havnafiord, and thence shipped to Copenhagen. The cost of transport brought the sulphur to too high a price to render the undertaking successful.

In 1857, political matters caused the attention of Her Majesty's Government to be directed to finding a new source of sulphur supply. Commander J. E. Commerell, of Her Majesty's ship Snake, was sent to Iceland by the Lords Commissioners of the Admiralty, to visit and report upon the capabilities of the mines of Krisuvik and Husavik. He found that the nearest safe port to the Krisuvik beds was Havnafiord; this port is 14 miles from the sulphur-beds by the present roads, and 9 miles from Reikjavik. The harbour is well sheltered, with good anchorage of 7 or 8 fathoms three cables length from the beach; it at present enjoys as much traffic as Reikjavik. The road from Krisuvik might be much shortened, and a tramway might also be laid down. During the past year a survey has been made, and plans drawn, for a railway or tramway to Havnafiord.

The actual extent of the sulphur-beds it is quite impossible to calculate; forty-seven have been already discovered. The deposit of sulphur Commander Commerell personally saw he describes as amounting to many thousands of tons, and, all the mines being in what is called a "living" state, the sulphur taken away is reproduced in two or three years. He considers that sulphur in a pure state could be shipped at Havnafiord for £1 per ton.

The sulphur at Myvatn, though great in quantity, is, he considers, at too great a distance from a port of embarkation to permit its extraction being carried on with any chance of competing with that from the Krisuvik mines.

No further steps were taken in the matter by the British Government, the political complications which led to the expedition having been removed; but the attention of English merchants having been drawn to these rich deposits by the highly favourable character of Commander Commerell's remarks, renewed attempts are being made to render commercially available the immense sulphur-producing power which the

Krisuvik solfataras undoubtedly possess. To some of these gentlemen I am greatly indebted for much valuable information, put at my disposal for the purposes of this paper, and, amongst them, I have specially to tender my thanks to Mr. Ramsdale and Messrs. Thorne, of Gracechurch Street, and particularly for the use of numerous and carefully-selected samples of the sulphur-earths which were freely placed at my disposal. These samples I hope to make the subject of a future paper.

Since writing the foregoing paper, I mentioned, in the course of conversation with Sir Henry Holland, the conclusions which are derived from the examination of all the trustworthy facts relating to the sulphur deposits. This led him to examine entries in his unpublished diary, made at Krisuvik in 1810. The theory which he then conceived so thoroughly agrees with all that has been learnt respecting the phenomena in question, that I, with his kind permission, print an extract from his note-book :

"The theory of these sulphurous springs (if springs they may be termed) at Krisuvik is an interesting object of inquiry. They are situated in a country decidedly of volcanic origin. The high ground on which they appear is composed principally of the conglomate or volcanic tufa, which has before been noticed. The source of the heat which can generate permanently so enormous a quantity of steam must, doubtless, reside below this rock; whether it be the same which produces the volcanic phenomena may be doubted, at least if the Wernerian theory of volcanoes be admitted. It certainly seems most probable that the appearances depend upon the action of water on vast beds of pyrites. The heat produced by this action is sufficient to raise an additional quantity of water in the form of steam, which makes its way to the surface, and is there emitted through the different clefts in the rocks. The sulphates of lime and alumina, appearing upon the surface, are doubtless produced, in process of time, by these operations. In corroboration of this view it may be observed that the quantity of steam issuing from the springs at Krisuvik is always greater after a long continuance of wet weather, and that whenever earthquakes occur on this spot it is during the prevalence of weather of this kind."

The learned, and now aged, author expressed the highest gratification that the views which he formed at twenty-two years of age should possess so much value so many years after.

During the reading of the paper Mr. Vincent illustrated his subject by several experiments, showing how the deposition of sulphur might have been effected. He also showed a spectrum obtained by burning some of the sulphur-earth, and it appeared that the thallium line became visible in the spectrum. Specimens of the various sulphur-yielding earths from Iceland were exhibited, and Dr. Clement Le Neve Foster showed samples from the Italian sulphur districts.

PROCEEDINGS OF SOCIETIES.

CHEMICAL SOCIETY.
Thursday, March 6th, 1873.

Dr. GLADSTONE, F.R.S., Vice-President, in the Chair.

AFTER the minutes of the previous meeting had been read and confirmed, and the donations to the Society announced, the names of Messrs. E. H. Fison, Charles Thomas Kingzett, Alonzo J. Rider, William Andrew Prout, B.A., Roland Finch, William Morgan, Ph.D., and Henry Richardson, were read for the first time. For the third time-Messrs. George Ainsworth, Alexander Bottle, Richard Joseph Deeley, and James Walter Montgomery, who were then ballotted for and duly elected.

The first paper, "On the Action of Hydrochloric Acid on Codeine," was then read by the author, Dr. C. R. A. WRIGHT, who, after referring to a former paper, containing an account of the action of hydrochloric acid on morphine, stated that codeine, treated with hydrochloric acid at 100° for 24 hours, gave a mixture of two bases, C+3HCl and C+4HCl-2H2O, where C stands for C36H42N206. When the action was continued for a longer time, methyl chloride was evolved, and a mixture of two isomeric bases obtained, intermediate in composition between morphine and "apomorphine "—namely, M2-2H2O and M-4H2O respectively, where M equals C34H36N2O5. With hydrobromic acid the first action was similar to that of hydrochloric acid, but its continued action gave rise to products which are not identical with those formed by means of hydrochloric acid, whether at 100° or at a higher temperature. An extensive table of the derivatives of codeine obtained up to this time accompanied the memoir.

After the Chairman had expressed the thanks of the Society to Dr. Wright for his valuable and laborious researches on this subject, a paper "On New Processes for Mercury Estimation, and some Observations on Mercury Salts," by J. B. HANNAY, was read by the Secretary. The author, finding the ordinary processes for the determination of mercury either very tedious or deficient in accuracy, has devised two new ones which are free from these objections. The first, which is a volumetric method, depends upon the fact that potassium cyanide dissolves the precipitate produced by ammonia in a solution of mercury chloride. A few drops of ammonia are first added to the solution containing the mercury in the state of chloride, and then a standard solution of potassium cyanide until the turbidity produced by the ammonia disappears. If arsenic, copper, &c., be present, the solution should be precipitated by sulphuretted hydrogen, the arsenic, &c., separated by sulphide of ammonium, and the mercury sulphide dissolved in aqua regia. The other method consists in decomposing the mercury, in solution as sulphate, by the electric current in a platinum basin, the mercury being deposited on the basin in the metallic state and weighed as such. The author has also made several experiments on mercury salts, and finds that hydrochloric acid completely decomposes mercury sulphate, and that mercury chloride can even be boiled with concentrated sulphuric acid without suffering decomposition.

Mr. F. FIELD remarked that, in separating the arsenic and antimony, potassium sulphide must not be used, as mercury sulphide was comparatively soluble in it.

The next paper, "On a Method of Estimating Nitric Acid," by T. E. THORPE, F.R.S.E., was also read by the Secretary. The author finds that the copper-zinc "couple" of Messrs. Gladstone and Tribe completely decomposes nitrates with formation of ammonia, which can then be estimated as platinochloride, or, if the amount be but small, by Nessler's test; particular care, however, is required with ammonium nitrate, the strength of the solutions employed considerably affecting the result. The author believes that this process, applied to the determination of nitrates in potable waters, possesses considerable advantages over the ordinary method-namely, by avoiding the introduction of nitrates in the potash or soda employed, and the frothing of the strongly alkaline solution when distilled. The author also employs the 'couple" for the reduction of chlorates and iodates it seems to have no action on urea.

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Dr. GLADSTONE said he had listened to the paper with great interest, and would welcome every labourer in the extensive field opened up by the use of the copper-zinc couple, since it was of great importance that we should know what substances were decomposed by it and what were not.

Mr. W. THORP said he was much pleased with the paper, and had no doubt the method would be valuable in determining nitrates when they were present in tolerably

large quantity, but he did not see the advantage it presented for water analysis over that devised by the late Mr.Chapman. He had made several hundred determinations by the last-mentioned process, but had never met with the difficulties mentioned by Dr. Thorpe. The presence of any trace of nitric acid in the potassic hydrate was readily removed by boiling the solution with a little aluminium. From the account given of it in the paper, he should imagine the new method to be more troublesome and tedious than the old one.

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Dr. DEBUS quite agreed with the speaker that the new method did not seem to possess any practical advantages over the old one. It was, however, interesting from a theoretical point of view that zinc and copper in contact should reduce nitric acid to ammonia.

A "Note on a Reaction of the Acetates upon Lead Salts, with Remarks on the Solubility of Lead Chloride," was then read by the author, Mr. F. FIELD, F.R.S. When sodium chloride is added to either lead acetate or nitrate, a white precipitate is formed, which is generally regarded

NEWS

as lead chloride; it is, however, entirely dissolved by acetic acid for the moment, crystals of lead chloride separating from the clear solution only after the lapse of a short time. By far the most sensitive test for the presence of acetates or formates is a copper salt in the presence of sodium chloride, for when such a solution is heated, a copious precipitate of oxychloride of copper is immediately produced. The author has also made some determinations of the solubility of lead chloride in a solution of sodium chloride, and notices the ease with which lead sulphate is decomposed by hydrochloric acid or sodium chloride, so that sulphuric acid produces no precipitate in a solution of lead chloride in sodium chloride.

In reply to a question by Dr. Voelcker, the author said he had not made any attempt to ascertain whether this method could be employed for the quantitative determination of acetic acid.

Dr. RUSSELL then took the chair, which was vacated by Dr. Gladstone to read a communication entitled "Observations on the Nature of the Black Deposit in the Copper Zinc Couple, by J. H. GLADSTONE, F.R.S., and A. TRIBE, F.C.S. As it had been suggested that the black deposit referred to, contained more or less metallic zinc, the authors had instituted experiments to ascertain the truth of the matter. When the solution of copper sulphate is poured on the zinc, a deposit of pure copper is produced as long as the solution contains any of that metal. As soon, however, as the copper is exhausted, other reactions supervene: zinc oxide is formed by the action of the oxygen dissolved in the water, and metallic zinc is also deposited. Such a black deposit examined under the microscope is seen to consist of branches of crystallised copper studded with crystals of metallic zinc, the latter of which at once disappear if washed with a solution of copper sulphate. It would therefore appear that the black deposit on the copper-zinc couple as usually prepared can contain little or no metallic zinc. The authors also made some remarks on the platinum-zinc and gold-zinc couples, which, as might have been expected, are more active than the copper-zinc couple, and concluded by a discussion of the theory of the electro-chemical actions involved.

Dr. RUSSELL, after returning the thanks of the Society to the authors for an account of their exceedingly interesting experiments, said that the statement, that as long as there was excess of copper sulphate in solution no zinc was deposited along with the copper on the zinc plate, was at variance with certain experiments he had made some time ago. When a zinc plate is immersed in a dilute solution of copper sulphate, it immediately becomes covered with a black deposit; but if the plate be moved about in the liquid so as to remove it from the solution of zinc sulphate formed in contact with it, the deposit immediately acquires a red colour. The black deposit, moreover, evolves hydrogen when treated with acid, whilst the red does not.

Dr. MULLER remarked that iron plunged into a solution of sulphate of copper gives at once a red deposit; moreover, any metal appearing black from being in a minutely divided state acquires its proper colour on being rubbed with an agate burnisher, but this black deposit does not.

Dr. WRIGHT observed that, a priori, it was quite possible that zinc and copper should be deposited together, since brass could be electro deposited.

Dr. SCHENCK drew attention to the fact that when a couple of copper and cadmium is immersed in a solution of cadmium sulphate, metallic cadmium is deposited on the copper.

A note on "An Air-Bath of Constant Temperature Between 100 and 200° C.," by Dr. H. SPRENGEL, was then read. This ingenious contrivance consists of a bath,similar to the ordinary hot-water oven, made of sheet-lead autogenously soldered, and filled with dilute sulphuric acid boiling at the desired temperature. In order that the temperature may remain constant, the water which distils from the

dilute sulphuric acid is condensed and allowed to flow back again into the bath by means of a worm of lead cooled by the atmosphere, or a long vertical metal or glass tube. Dr. RUSSELL in thanking the author, said the Society was much indebted to him for his simple and ingenious form of air-bath, and finally adjourned the meeting until Thursday, March 20, when a lecture "On Iron and Steel" will be delivered by C. W. Siemens, Esq., F.R.S., &c.

MANCHESTER LITERARY AND PHILOSOPHICAL

SOCIETY.

Ordinary Meeting, February 18th, 1873.

E. W. BINNEY, F.R.S., F.G.S., Vice-President, in the Chair.

DR. JOULE, F.R.S., gave some further account of the improvements he had made in his air-exhausting apparatus. As stated in the last Proceedings, he had substituted a caoutchouc tube, attached to the neck of a glass vessel, for the original perpendicular pipe with its stopcock. This is seen in the sketch (see preceding page), c and d. The two positions-viz., when b is being filled, and when it is being emptied-are shown by the full and the dotted drawing. It is convenient to introduce no air into d except that required to act as a cushion to avoid a shock when filled in the lower position. Sulphuric acid may be introduced into the receiver to be exhausted, but it is perhaps more convenient to place it over the mercury in a, whence it may occasionally be drawn into b, to effect the drying of the internal parts of the apparatus. Dr. Joule has met with some difficulty in using mercury gauges to ascertain the residual pressure, inasmuch as he finds that mercury thoroughly boiled in clean glass tubes does not show a convex surface, but adheres strongly to the glass, However, he has confidence in giving the following results, in working with his apparatus with acid of various strength, obtained by successive dilutions of sulphuric acid of ep. gr. 1845 by volume:

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Present Condition of Agricultural Science in France and Other Countries.-L. Mussa.-The continuation of this monograph. This portion is divided into the following sections:-Aerial nutrition; carbonic acid; nitrogen; respiration of plants; elaboration of the juice in the leaves: perspiration of plants; flowers (blossom, bloom), their functions; the fruit; seed, grain and its ripening; the seeds of plants; germination of the seed. To be continued.

On Aniline Blacks.-C. F. Brandt.-This paper treats at length on the modes of preparation, formation, and nature of the aniline

blacks, which consist, according to the author, of two distinct blacks mixed together in variable proportions. One of these, formed by the chlorated substitutes of aniline, is very fast, resisting almost all

chemical reagents; but alone it is less beautiful than the other black, the product of the oxidation of the aniline salt. This substance really exhibits a deep violet-blue hue, which appears black in the concentrated state, but it is far less fast than the former; and although it resists soap, it becomes of a greenish colour by even very weak acid. In order to obtain a beautiful as well as a fast black, it is necessary for the two blacks to be present in proper proportion, and this depends upon the proportion of chlorate contained in the mixture.

New Researches on Propionic, Butyric, and Valerianic Acid.-T. Pierre and E. Puchot.-This exhaustive monograph is divided into the following sections:-Propionic acid, its mode of preparation; salts, viz., baryta, silver; butyric acid, its mode of preparation from butylic alcohol by oxidation, and properties of the acid; salts, viz., baryta, silver, ethylic, methylic; valerianic acid, mode of preparation from valerianate of potassa.

Bibliography.-Under this heading attention is called to the following new publications:-"Traité de la Détermination des Terres Arables dans le Laboratoire," par M. P. de Gasparin; Paris: G. Masson. This book has been specially written for agriculturists, and contains instructions for the easy estimation of phosphoric acid, potassa, lime, magnesia, soda, silica, iron, alumina, &c. in arable soils. All the described processes of analysis have been tested and practically studied by the author, who is an eminent practical agriculturist, and also a distinguished chemist. "L'Année Scientifique et Industrielle, ou Exposé Annuel des Travaux Scientifiques, des Inventions et des Principales Applications de la Science à l'Industrie et aux Arts qui out Attiré l'Attention Publique en France et à l'Etranger, Accompagné d'une Nécrologie Scientifique," par M. Louis Figuier; Paris: Hachette et Cie, The sixteenth yearly volume of this work contains a resume of the labours of scientific institutions and societies. The other portions of this valuable recueil have also been greatly extended.

Les Mondes, March 6, 1873.

Election of Berthelot.-This celebrated savant has been elected one of the Fellows of the Académie des Sciences by a large majority. Synthesis of Acetic Acid.-A. and J. Thenard.-By passing the electric current of a Ruhmkorff coil through a mixture of carbonic acid and protocarburetted hydrogen, the authors have, in the presence of M. J. Dumas, obtained acetic acid; thus combining two inorganic compounds in an organic substance.

Artificial Production of Cold by the Expansion of Air.-J. Armengaud.-The author has constructed an apparatus in which the perature is 15° it leaves the apparatus at -20°. air may be made to expand so rapidly, that while on entering its tem

Volatilisation of Iron.-Dr. Elsner.-The author, director of a royal porcelain manufactory at Berlin, has placed in an unglazed porcelain crucible, closed with a lid, a piece of malleable iron, and exposed it for several hours to a temperature of at least 3000° (the heat of the porcelain kiln). On withdrawing the crucible from the kiln the lid was found lined with small crystals (needle-shaped) of iron which had been volatilised.

Bibliography.-"L'Architecture du Monde des Atomes," par M. A. Gaudin; Paris: Gauthier-Villars. This work is highly spoken of by the celebrated savant, Dumas, and contains the results of the author's labours during the last forty years. "Les Machines; leur Historie, leur Description, et leur Usages," par E. With; Paris; Baudry. A complete mechanical technology, illustrated by woodcuts, and full of useful as well as practical information.

Petites Annales de Chimie.-E. J. Maumené.-The twelfth por. tion of this monograph, elucidated by a large number of algebraico. chemical formule.

Flame of Compressed Gases.-F. Benevides.

Annalen der Chemie und Pharmacie, vol, clxvi., No. 2, March 1, 1873. On Some New Derivatives of Sulpho-Carbaminic Acid.H. Hlasiwetz and J. Kachler.-In the introduction to this essay the authors refer to the researches of Städeler and E. Mulder on this subject. Then we have the detailed account of the mode of preparation and properties of a peculiar combination of ammonia and sulphide of carbon, which is formed only when the two bodies are reacting upon each other in the presence of camphor. The new substance so obtained is a solid crystalline material, formula, C2H10N4S. It is unstable, and readily decomposed by nitric acid and caustic alkalies; it yields with sulphate of copper a yellow-coloured compound

C2H2Cu"NS2.

When the body first mentioned is treated with perchloride of iron, there is formed a new compound, C2H,N,S,, a crystalline substance, quite insoluble in water and ether, but soluble in boiling alcohol. The body CH10NS, forms with aniline a crystalline compound, soluble in boiling alcohol, formula, CH1N4S. The authors propose to call these compounds "thiuram" (from Bewv) because the group NH2-CS prevails in these bodies. A series of formulæ, with the addition of the old and new names, is given.

Some of the Nitrogen Compounds of Anthrachinon.-R. Boettger and Th. Petersen.-The second instalment of a monograph on this subject. This portion is divided into the following sections:a-mononitro-anthrachinon, C1H,(NO2)O2; a-monoamido-anthrachinon, CH,(NH2)O2; a-diazo-anthrachinon-nitrate,

C14H,N2O2.NO3;

behaviour of mononitro-anthrachinon with concentated sulphuric acid.

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