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Storms," by the President, J. P. Joule, LI..D., &c. "On the Tongues of Mollusca," by Dr. Thomas Alcock. "On the Employment of Galvanised Iron for Armour-plated Ships," by Dr. F. Crace Calvert, F.R.S.

April 1, 1862.-""On the Effect of Increased Temperature upon the Nature of the Light emitted by the Vapour of certain Metals or Metallic Compounds," by Professors Clifton and Roscoe. "Notes on Calorific Phenomena," by J. C. Dyer, V.P.

April 15, 1862.-"On the Theory of the Transcendental Solution of Algebraic Equations," No. 3, by the Rev. Robert Harley, F.R.A.S. "On the Putrefaction of Blood," No. 2, by Dr. R. Angus Smith, F.R.S. "On the Relations between the Decrement of Temperature on ascending in the Atmosphere, and other Meteorological Elements," by J. Baxendell, F.R.A.S.

April 29, 1862.—" On Non-Modular Groups," by the Rev. T. P. Kirkman, A.M., F.R.S., &c.

The Council have decided to print several of the above papers in the next volume of the "Memoirs."

The Report of the Librarian shows that a very large increase has this year taken place in the stock of valuable scientific books of reference in the library. The Society is now (through the unwearied exertions of the Librarian) in regular communication and exchanging publications with all the most important Academies and learned Societies throughout the world; and a scientific library of reference is being gradually collected, the importance of which, especially to those engaged in scientific research, cannot be over-estimated. In order to complete the sets of the series of "Transactions," the current and future numbers of which are obtained in exchange for the Society's "Memoirs," a much larger sum of money is requisite than the ordinary income of the Society cau supply. A sum of 851. 75., being the balances due to the subscribers of the British Association local fund, has been kindly placed by them in the hands of the Treasurer, for the purpose of assisting our Librarian to carry out this important work.

In conclusion, the Council report with satisfaction the increased activity and usefulness of the Sections, as shown by their published proceedings.

MICROSCOPICAL SECTION.
April 27, 1862.

E. W. BINNEY, F.R.S., F.G.S., in the Chair. Contributions were acknowledged from Captain James Clarke, of the ship Lightning, consisting of a specimen of mud from Hobson's Bay, Australia; a specimen of Fucus natans, or gulf-weed, from the Sargasso Sea; and sand, &c., from a sounding off the south coast of Ireland. Captain Contente, of the Portuguese steamer Lusitania, forwarded a sounding taken between Cape Carvoeiro and the Berling Islands, off the Coast of Portugal.

Professor CALVERT presented to the members of the Section a number of bottles containing carbolic acid in crystals, for the purpose of experimenting upon its utility as a preservative fluid for microscopical objects, as well as for specimens of natural history.

Mr. THOMAS D. TOASE, of Jamaica, presented, through Professor Calvert, specimens of Diatomacea, from Kingston Harbour; pollen of a West Indian lily; a portion of a plantain leaf, with two mounted slides of the same, showing cells, raphides, &c. Mr. Toase also sent drawings and description of a rotifer, found upon Conferva, at Jamaica, which is not known to any of the members present. It consists of an oval body or outer case of a brownish colour, fth of an inch in length; from near one end of the oval is protruded a transparent neck or contractile body, furnished when protruded with four hairs or feelers, a lip, and a kind of operculum, around which Mr. Toase recognised the presence of cilia by the current of water, but he failed to discover the cilia for want of defining power in his microscope. There is not sufficient detail either in the

CHEMICAL NEWS, June 14, 1862.

description or the drawings to be of much use to the microscopist, but further information has been written for. Mr. BROTHERS presented to the Section photographs of the four drawings by Dr. Alcock, illustrating his paper on the " Tongues of the Mollusca,"

Mr. SIDEBOTHAM exhibited a drawing of an undescribed species of Zygnema, found by Mr. Watson and himself, at Southport, in brackish water. It exhibited no appearance of conjugation, and the spores were like balls covered with spines, which when released from the cells move rapidly through the water like volvox.

Mr. MOSLEY reported upon the specimen of the outer coating of a bulb, received through Dr. Fairbairn from Mr. Niven, of Jeffrey's Bay, Cape of Good Hope. On examination with the microscope, he found that the leaf is about both of an inch in thickness; that between the outer and the inner cuticle a number of tubes or vessels run longitudinally through the structure of the leaf; and that these tubes are composed of very delicate fibres, coiled up so as to form spiral vessels. On breaking the leaf, the fibres may be uncoiled and drawn out to an almost indefinite extent. From the thicker middle portion Mr. Mosley had drawn out fibres to the extent of eighteen or twenty inches without breaking; they are beautifully fine, but are, in his opinion, too weak and delicate, as well as too long, to be used as a substitute for cotton. He considers it possible some application may be found for the fibre, if a sufficient sample were sent for experimental trials. Desirous of knowing the botanical history of the plant, he wrote to Sir W. J. Hooker, Director of the Royal Gardens at Kew; but it was not possible to classify the plant with certainty from a specimen so imperfect. Sir William observed that in all probability it is one of the Amaryllidacea, and possibly of the genus Buphane.

Mr. MOSLEY also exhibited the leaf of a new species of Digitalis, brought by Mr. Hurst from the Hazaree-bagh, Bengal, upon the surface of which the poison-glands are closely set in groups of four glands, placed in a lozenge form.

Mr. NEVILL exhibited a new form of microscope, by Matthews, of London, for field use or class instruction, which can be used with either transmitted or reflected light. Mr. Nevill proposed that the subject for discussion at the next meeting should be, "On the Motion of the Navicule," which was agreed to.

NOTICES OF BOOKS.

A Manual of Domestic Economy. By W. B. TEGETMEIER. Sixth Edition. Home and Colonial School Society, Gray's Inn Road, London. 1862.

IN noticing the sixth edition of Mr. Tegetmeier's "Domestic Economy," it is scarcely necessary for us to do more than state our conviction that the success and general appreciation of the book are well merited. The way in which the more important applications of chemical principles to the cooking of meat, and many other household operations are explained, must effect much benefit. The author does not hesitate to express in decided terms the conclusions of sound science, even where they militate against popular notions. His remarks on the injurions results of the salting process on meat are very just; whilst in many matters which scarcely come within our scope, his advice is not less admirable: where, for instance, he guards the novice in dusting from the two extremes of flapping the dust from one end of a room to the other," and those more violent measures which produce dust rather than get rid of it; the dust being in such cases nothing more than furniture in a fine state of division.

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Royal Institution. — Friday, June 20, at Eight o'clock, Professor Faraday, F.R.S., "On Gas, Glass Furnaces, etc."

NOTICES OF PATENTS.

submitted to the action of chloride of lime or other bleaching liquor.

This expedient has long been known, and frequently 1481. Treating Skins. J. STEART, Blue Anchor Road, been put in practice in bleaching and dye works as a Bermondsey, London. Dated June 10, 1861. means of liberating more quickly the active chlorine.

THE inventor employs in the preparatory stage of treating skins a gelatinous product obtained by digesting fish with water, under heat and pressure, until it is reduced to a pulpy mass. By the use of this animal product, the depilated skins are rendered fit to undergo the tanning process in the usual manner.

1489. Impermeable Varnish for Leather. C. STEVENS, Charing Cross, London. (A communication.) Dated June 11, 1861.

FOR the purpose of coating leather, and conferring upon it waterproofing qualities, the patentee employs a varnish composed of india-rubber dissolved in bisulphide of carbon, and he prefers to use this in conjunction with another varnish made with gutta-percha instead of india-rubber, and applied as a second coating. In the preparation of these varnishes one part of either of the natural gums is dissolved in a closed vessel in four parts of bisulphide of

carbon.

1861.

1566. Cements or Adhesive Solutions for Joining or Connecting together Surfaces or Articles of Leather, Wood, Paper, &c. J. McKAY, Birmingham. Dated June 18, THE patentee employs in the manufacture of these adhesive solutions the bisulphide of carbon, in which he dissolves purified gutta-percha, leaving the vessel open in order to allow the bisulphide of carbon to take up a sufficient amount of oxygen !

Is there not something anomalous in the state of the law which permits of the sealing of two patent claims within the period of a week for the selfsame material and application? The chief difference in the wording of the preceding specifications arises from an erroneous conception in regard to the nature and chemical properties of the bisulphide of carbon, so that while one patentee makes his varnish in a closed vessel to avoid loss of solvent, the other specifically directs the vessel to be left open. Furthermore, it is impossible that either of these patent claims can be supported on the score of novelty, since the same suggestion was made the subject of a provisional specification more than a year earlier, but was not proceeded with at the expiration of six months.*

1507. Converting Vegetable Fibrous Substances into Pulp. J. WATT, Camberwell, Surrey. Dated June 12, 1861. THIS invention relates to a mode of treatment for converting fibrous vegetable structures into pulp, and consists in submitting them to the action of carbonate of soda or potassa, at the boiling point of these solutions, wherein they are left until the fibres of the vegetable substance have become loosened and separated. They are then

washed and bleached either with chloride of lime, or chloride of soda, and are then ready to be made into pulp.

These operations, in the same order of succession, have frequently been applied to the disintegration of soft vegetable structures, the patent claim of Mr. J. H. Johnson † may be quoted as an illustration of a similar mode of treatment.

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CORRESPONDENCE.

Bluish Vapours of Chloride of Ammonium. To the Editor of the CHEMICAL NEWS. SIR,-I am very glad to learn, by the remarks appended to my letter in your last Number, that I was mistaken in supposing that any part of your comments on the chemical evidence given on the trials of "Downing v. Chance," and "Timmins v. the Staffordshire Gas Company" was intended as a personal attack upon myself. This being the case, I shall have much pleasure in explaining those parts of my evidence which, as reported in the newspapers, have appeared so "curious" to yourself, and, probably, to your readers.

My evidence on the point was correctly enough reported Firstly, as regards the bluish vapours or rather fumes. so far as the report went; but being only a short abstract, the explanation which I gave of the circumstances under This explanation was brought out by the cross-examination, which the blue colour was exhibited was not included. and had it been fully reported there would have been no need for that which I am now about to supply.

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The experiments were made as follows: hour's driving round about the works, and climbing over the ashy mounds of the black wilderness of their vicinity, I fixed upon a retired acre of cinders, along which the "chemical smoke," or "chemical," as it is called by the natives, was occasionally drifting whenever the variable gusts of wind then blowing beat it downwards. poured about two ounces of strong solution of ammonia on one cone of cinders, and two ounces more on another at some distance from it, and on a cord stretched between two walking-sticks hung some filtering paper saturated with ammonia, both of which were previously tested and found free from any trace of hydrochloric acid. This paper was afterwards taken to the laboratory of the Midland Institution, and tested in the usual manner for chloride. Whenever a waif of "chemical" (which is ground, bluish fumes hung around and drifted from the a readily distinguishable white vapour) drifted over the mounds and the paper, most notably from the cinder cones. The colour of these fumes was identical with that which reeks from the tip of a good cigar, and is so readily distinguishable in tint from that which comes from the mouth of the smoker. To the chemist who is only familiar with the usual laboratory experiment of bringing a stirring rod moistened with strong hydrochloric acid into the midst of ammoniacal gas, this bluish colour may be a novelty, but to the farmers whose dunghills are occasionally visited by the fumes from alkali works it is a very familiar phenomenon. The primary condition determining this bluish colour is that the hydrochloric acid fumes shall be much diffused and spread over a large space. The tint is heightened if the fumes are projected against a dark background, and the spectator stands with his back to the light.

These conditions may easily be fulfilled in a laboratory, by pouring a little solution of ammonia on the ground, or on a table, &c., and standing with back to the window, at a distance of a yard or two from the ammonia, blowing the the ammonia. The bluish colour of the chloride of fumes from the mouth of a hydrochloric acid bottle towards ammonium fumes will then be sufficiently apparent.

simple fact; but it appears to be really of some importance This is a very simple experiment to establish a very in judicial inquiries of this kind, for the chemist who only seen the white fumes formed in the usual

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College.

CHEMICAL NEWS, June 14, 1862.

testing for ammonia, or in the lecture-table experiment of and Caius College. Local Treasurer for the Meeting at mixing the two gases in a more concentrated form, would | Cambridge-The Rev. W. M. Campion, M.A., Queen's question the accuracy of the statements concerning these blue vapours over the dunghills, which were made by all the unlearned agricultural witnesses in the trial of "Downing v. Chance."

If I might venture upon an explanation of the differences of colour of such fumes under such circumstances, it would be this. These fumes consist, of course, of minute crystals of chloride of ammonium. A clear crystal, or a clear homogeneous mass of this salt, has a rather strong bluish tint, while a mass of detached or lightly cohering crystals is snowy white, and semi-opaque. This is a very common, I might say a general variation in the appearance of such bodies; the difference between ice and snow, rock salt, and granular table salt, lump sugar, and single sugar crystals, &c., are familiar illustrations.

The fumes of hydrochloric acid consist of particles of the gas combined with water in the vesicular state or otherwise. When these particles are comparatively far apart, as in the more diffused fumes, they would form isolated crystals; but when close together, as in the dense fumes, it is very probable that many crystals would coalesce at the moment of formation, and form flocculi-like snow flakes, or granular hail, and these flakes, of course, would be white, and the isolated crystals of the more diffused fumes bluish.

This explanation is further confirmed by the fact that the bluish fumes remain suspended in the air a far longer time than the white fumes, indicating that the blue fumes consist of smaller particles than the white fumes.

There are other cases of a similar kind that may be explained in the same manner, but regard for your space and my own time prevents me from citing further illustra tions at present. For the same reasons I must postpone until next week an account of the unexpected Magenta coloured reaction I obtained by the direct action of dilute nitric acid upon certain coal products.-I am, &c. W. MATTIEU WILLIAMS.

Hall Road, Handsworth, near Birmingham, June 10.

MISCELLANEOUS.

BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE.

The thirty-second meeting will commence at Cambridge on Wednesday, October 1, 1862, under the direction of the following officers :-President, Rev. R. Willis, M.A., F.R.S., Jacksonian Professor of Natural and Exreri. mental Philosophy in the University of Cambridge. VicePresidents-The Very Rev. Harvey Goodwin, D.D., Dean of Ely; the Rev. W. Whewell, D.D., F.R.S., Master of Trinity College, Cambridge; the Rev. A. Sedgwick, M.A., D.C.L., F.R.S., Woodwardian Professor of Geology in the University of Cambridge; G. B. Airy, Esq., M.A., D.C.L., F.R.S., Astronomer Royal; J. C. Adams, Esq., M.A., D.C.L., F.R.S., Pres. C.P.S., Lowndean Professor of Astronomy and Geometry in the University of Cambridge; G. G. Stokes, Esq., M.A., D.C.L., Sec. R.S., Lucasian Professor of Mathematics in the University of Cambridge. General Secretary-William Hopkins, Esq., M.A., LL.D., F.R.S., F.G.S., Cambridge. Assistant-General Secretary-John Phillips, Esq., M.A., LL.D., F.R.S., F.G.S., Professor of Geology in the University of Oxford. General Treasurer-William Spottiswoode, Esq., M.A., F.R.S., F.G.S., F.R.A.S., &c., 19, Chester-street, Belgrave square, London, S. W. Local Secretaries for the Meeting at Cambridge-Charles C. Babington, Esq., M.A., F.R.S., F.L.S., Professor of Botany in the University of Cambridge. G. D. Liveing, Esq., M.A., Professor of Chemistry in the University of Cambridge. The Rev. N. M. Ferrers, M.A., Gonville

The General Committee will meet on Wednesday, October 1, at 1 p.m., for the election of sectional officers, and the despatch of business usually brought before that body. On this occasion there will be presented the report of the council, embodying their proceedings during the past year. The general committee will meet afterwards by adjournment.

The first general meeting will be held on Wednesday, October 1, at 8 p.m., when the President will deliver an address; the concluding meeting on Wednesday, October 8, at 3 p.m., when the Association will be adjourned to its next place of meeting.

At two evening meetings, which will take place at 8 p.m., discourses on certain branches of science will be delivered.

There will also be other evening meetings, at which opportunity will be afforded for general conversation among the members.

The Committee of Sections will meet daily, from Thursday, October 2, to Wednesday, October 8, inclusive, at 10 a.m. precisely.

The Sections will meet daily, from Thursday, October 2, to Tuesday, October 7, inclusive, at 11 a.m. precisely.

Reports on the Progress of Science, and of researches entrusted to individuals and committees, and other communications intended for presentation to the Sections, are expected to be forwarded in letters addressed to the Assistant General Secretary, at Cambridge, previously to the meeting, accompanied by a statement whether the author will be present, and on what day, so that the business of the Sections may be satisfactorily arranged.

The reports complete, and concise abstracts of other communications, are to be delivered to the Secretaries of the Sections before which they are read, previously to the close of the meeting, for publication in the Transactions. As the Reports on Science may be more interesting to more Sections than the one which originally called for them, it is desirable that the authors should be prepared to furnish the means of reading them in any other Section at the request of the President and Secretaries of that Section.

The following are the titles of the Sections to which communications may be presented :-Section A. Mathematics and Physics. B. Chemistry and Mineralogy, including their applications to Agriculture and the Arts. C. Geology. D. Zoology and Botany, including Physiology, Sub-Section D. E. Geography and Ethnology. F. Economic Science and Statistics. G. Mechanical Science.

Members will receive their tickets in the reception room according to their class of membership, separate registers being appointed for old life members, old annual subscribers, new annual subscribers, and associates.

Gentlemen desirous of attending the meeting will find in the reception room blank forms of proposal, and may make their choice of being proposed as life members, paying ten pounds as a composition, or annual subscribers, paying one pound annually and an admission fee of one pound (making together two pounds on admission), or associates for the meeting, paying one pound.

Ladies may obtain tickets, through the application of a member, in the reception room, price one pound each ticket. These tickets are transferable to other ladies only.

Compositions, subscriptions, and arrears are received during the meeting in the reception room, and at all times by the Local and General Treasurers.

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THE CHEMICAL NEWS.

VOL. V. No. 133.-June 21, 1862.

SCIENTIFIC AND ANALYTICAL CHEMISTRY.

On the Preparation of Oxalic Ether, by M. Kolbe.* MIX 180 grs. of oxalic acid, dried at 100°, with 100 grs. of acid sulphate of potash, and submit them, in a retort, to the action of a temperature of 150° or 180° C. Then drop gradually into the tubulure of the retort a mixture of 250 grs. of absolute alcohol and 25 grs. of concentrated sulphuric acid; cohobate and distil at a temperature not below 150° C. After shaking up the product of the distillation with some water, dry over chloride of calcium and rectify. The product is about 70 per cent. of the quantity indicated by theory, basing it on the oxalic acid used. By adding ammonia to the mother-waters, a considerable quantity of oxamide is also obtained.

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When heated in a platinum capsule it almost entirely disappears, leaving only a slight trace of a black substance, insoluble in nitric acid, and giving the reaction of silica before the blow-pipe.

Of the 87.600 of total sulphur contained in this substance, 64 26 dissolve readily in aqua regia, but the remaining 23 34 per cent. resist the action of aqua regia, and were not dissolved after boiling with excess of the latter for upwards of two hours.

The preparation of selenium from this impure sulphur is not difficult. The substance being finely pulverised,

* Annalen der Chemie und Pharmacie, vol. cxix. p. 172.

is oxidised by aqua regia, the solution diluted and filtered, thus separating the sulphur which remains undissolved. A few crystals of sulphite of soda are then dissolved in the liquid, until the latter acquires a permanent odour of sulphurous acid, and the whole allowed to repose for about forty-eight hours, at the expiration of which the whole of the selenium is deposited as a rose-red powder. In this manner from o'3 to 0'4 per cent. of selenium can be obtained; but if, instead of using aqua regia to oxidise the sulphur, the latter be treated with carbonate of soda and nitre, in the dry way, no selenium at all is obtained.

Reduction of Sulphuric Acid by Nascent Hydrogen, by M. KOLBE.†

IT is an established fact that when sulphurous acid is reduced by nascent hydrogen sulphuretted hydrogen is produced. MM. Fordos and Gélis have founded upon this reaction a very simple process for recognising the presence of sulphurous acid; but it has hitherto been unknown that sulphuric itself, under these circumstances, Hydrosulphuric gas, undergoes a similar reduction. which always contaminates hydrogen prepared with zinc, water, and sulphuric acid, has probably no other origin. M. Kolbe has remarked that this gas is developed in increasing quantity proportioned to the degree of concentration and high temperature of the acid.

This is not an unimportant phenomenon. It can be prevented by employing sulphuric acid previously diluted with twice its volume of water, in which case pure hydrogen is produced; but if concentrated acid is then poured into the mixture, hydrosulphuric gas speedily

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Preparation of Iodide

of

Calcium. - Hesse

(Chemisches Central-Blatt, 1862, p. 174) prepares iodide of calcium by adding milk of lime in excess to a solution of the iodide of iron. Any excess of lime in solution with the iodide of calcium is separated by evaporating the solution, or better, by passing carbonic acid through the hot solution.

* That is the amount yielded by the specimens I have examined; but I believe the environs of Naples furnish sulphur which, treated as above, would yield considerably more.

t Annalen der Chemie und Pharmacie, vol. cxix. p. 174.

This fact connects itself with the other facts ascertained by M. Blondlot, whilst treating organic matters with sulphuric acid in order to isolate arsenic. The error can doubtless be rectified by the means this chemist indicates. (See Journal de Pharmacie et de Chemie, vol, xxxi. p. 117.)

338

TECHNICAL CHEMISTRY.

On Aluminiuт.

On Aluminium, by J. W. M'GAULEY. THERE is no subject connected with chemistry of more importance than that of the metals; nor is it an exaggeration to assert that they have been the principal agents in civilisation. We are chiefly indebted for the latter, however, not to those which are costly and rare, but to that which, by a beneficent dispensation of Providence, is the most common of them all; since iron has been of far more value to mankind than gold.

The ancients were acquainted with but few metals. In very remote antiquity, metallurgical knowledge was almost confined to copper and tin, which were more easily reduced than iron. And, as it was soon discovered that some of their alloys were extremely hard, they were employed in the manufacture of axes, swords, and other weapons, after still ruder materials were discarded; hence, warlike and domestic instruments of bronze are found among the oldest relics of distant ages. But iron at length obtained its fitting place among the substances useful to man; and its abundance, its extreme softness when softness is required, its extreme hardness when that quality is desirable, its elasticity, its malleability, ductility, tenacity, and other admirable qualities, have caused it to acquire and maintain the very first rank among the useful metals. Gold and silver, it is true, have been known from the earliest times; but their use, like their supply, has always been limited; and much of the value attached to them is due to their scarcity. Lead, also, and zinc-at least as an ore, and as one of the ingredients of brass-were familiar to the ancients. But we have now enumerated all the metals with which they were acquainted; and, in truth, all that to any great extent have yet been utilised.

We are, on this occasion, specially to treat of a metal which has been a source of great expectations; and, fortunately, there is no reason to consider that these have been disappointed; their complete realisation is only deferred, and most probably for but a short period; and one of our objects in directing attention to it, is to excite a more general inquiry regarding it. The establishment of aluminium among the most important of the metals is a mere question of the cheapness of its production; and as, up to this time at least, it is most conveniently obtained by means of sodium, investigations regarding it resolve themselves into a determination of the most economical method of obtaining that metal. On this point our knowledge has also progressed considerably, and hence the price of aluminium has greatly fallen. Not long ago it was 37. per ounce, it is now only about 58.; and it will, no doubt, be far less, if we are to judge by the extraordinary improvements always made, after a time, in chemical processes. How much lower in price are the most useful substances at present than they were a few years ago, because the methods of manufacturing them have been simplified. But even at its present cost, which, by weight, is the same as that of silver, aluminium is really only one-fourth as dear, bulk for bulk; and this, after all, is the test, since bulk for bulk, it is as strong, and even stronger than silver. When there is question, however, of its application to domestic purposes, we must compare its cost with that of pewter or copper; it would chiefly supersede these, which, among other disadvantages, are productive of very noxious compounds, particularly the copper.

The qualities of the precious metals are quite distinct

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CHEMICAL NEWS,
June 21, 1862.

from those of the more common; nor have the two classes hitherto been connected by any intermediate metal-that is, by one possessing the most characteristic properties of each; but it is hoped that aluminium may supply such a connection. Like the precious metals, it is brilliant, and little alterable by chemical agentsscarcely at all, under ordinary circumstances. Like the common metals it is very abundant, constituting onefourth, by weight, of the most widely diffused bodies. It is malleable, ductile, hard, and tenacious; its compounds are harmless-which is true of scarcely any other metal but iron; and, unlike both the precious and the common metals, it has the advantage of being extremely light. It is admirably suited to all ordinary purposes, and is one of the best that can be used for those which are artistic and ornamental. M. Christofle, in 1858, exhibited before the Academy of Sciences a group in aluminium, which had been cast and chiseled, and which afforded an excellent example of its capabilities, though it was its first application to such a purpose. Davy, soon after he had discovered the metallic bases of the alkaline earths, in 1807, proved the existence of aluminium, from potassa being produced when the vapour of potassium was brought in contact with alumina heated to whiteness; and he even obtained it in combination with potassium. It was procured by Wöhler, in 1827, as a grey powder, and, in 1845, in the form of very minute globules; but probably from being more or less impure, it did not exhibit the same properties as when in a massive state. On account of the high price of potassium at the time he made his experiments, and other obstacles, he did not obtain it in particles larger than a pin's head; and he succeeded in uniting these only by great chance, and after many trials; since the presence of minute quantities of other substances, or a slight coating of oxide, would prevent their coalescing. M. Degousse, a gold-beater, of Paris, succeeded in preparing it in the form of very thin plates; and he found that in beating them out, it was necessary to re-heat them more frequently than other metals in similar circumstances. M. Deville has been the most successful of all those who have made experiments upon it. We shall first describe the most convenient methods of obtaining aluminium, particularly on the small scale, and shall then examine its properties and combinations

omitting nothing of any importance that has yet been discovered regarding it. As to the mode of procuring it on the large scale, it does not concern the object we have in view; but it may, in a great degree, be conceived from what we shall say.

When we attempt to get aluminium directly from alumina, with potassium, or sodium, we do not succeed; most likely from its being necessary that the potash or soda, which would then be formed, should unite with some of the undecomposed oxide, which does not seem to occur, though aluminates of the alkalies are very easily made. But M. Chapelle, in 1854, procured it by introducing pulverised clay, sea-salt, and powdered charcoal into a common crucible, and heating the mixture with coke, though not to whiteness, in a reverberatory furnace. When the crucible was cold, a considerable quantity of minute globules of aluminium were found at the bottom. It must be admitted that the simplicity of this method, if it could be rendered economical, would make it deserving of preference; and it is not improbable that it may hereafter be so improved as to supersede all others. To obtain aluminium through the medium of a troublesome metal seems at best a clumsy process. It is, however, the most successful that has been yet devised; and

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