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NEWS

colours. The white balls are hydrogen, the green ones chlorine atoms; the atoms of fiery oxygen are red, those of nitrogen, blue; the carbon atoms, lastly, are naturally represented by black balls. But we have, in addition, to exhibit the different combining powers of these atoms. FIG. 5.

foundation, on each of which we place a hydrogen sphere as the first building stone.

by inserting the solid arm of the former into the tubular On one of these hydrogen atoms we fix a chlorine atom arm of the latter, we have thus constructed a molecule of hydrochloric acid. The attraction units of the two elements are saturated; we can add no more; the building is finished.

FIG. 7.

Formation of HYDROCHLORIC ACID.

The next hydrogen atom we combine in a similar manner with an atom of oxygen, but no closed molecule is thus produced. One of the attraction units of the oxygen is not yet saturated, as indicated by the one arm remaining uncovered. Only by fixing upon this arm a second hydrogen atom we saturate this second attraction unit also. The closed water molecule is a finished building.

FIG. 8.

This we accomplish by screwing into the balls a number of metallic arms (tubes and pins), which correspond respectively to the combining powers of the atoms represented, and which, while constituting an additional feature of distinction, enable us at the same time to join the balls and to rear in this manner a kind of mechanical structure in imitation of the atomic edifices to be illustrated. Thus the hydrogen and chlorine atoms, which are univalent atoms, have each one arm, representing one combining cr attraction unit; the atom of oxygen, a bivalent atom, has two, representing two attraction units; while the nitrogen and carbon atoms, respectively trivalent and quadrivalent, are provided with three and four arms, indicating the three and four combining units respectively distinguishing these atoms.

FIG. 6.

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Of the newly-formed building materials let us make a preliminary trial in constructing the four hydrogen compounds just examined.

We start with four appropriately disposed stands as a

Formation of AMMONIA.

In a similar manner, lastly, we perceive that when a four-armed carbon atom is fixed upon the hydrogen atom, the three combining units remain unsaturated, and that the construction of a closed molecule of marsh-gas can be accomplished only by the accession of three atoms of hydrogen.

FIG. 10.

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material may be handled enables us to construct even some of the more complicated substances involved in these considerations. And, first, the building up of the oxygen compounds of hydrochloric acid may be attempted. On opening the molecule of hydrochloric acid, two attraction units (one belonging to the hydrogen atom, and the other to the chlorine atom), are liberated; they are exactly equal to the two attractions of the bivalent atom of oxygen. With the insertion of an oxygen atom, we perceive that the molecule is closed again; no uncovered arm projects, no attraction remains unbalanced. This new molecule-we call it hypochlorous acid-we open again; again two attraction units are liberated and saturated by a second atom of bivalent oxygen. The molecule of hypochlorous acid is

The

thus converted into the molecule of chlorous acid. insertion of one or two more oxygen atoms under exactly similar circumstances would give rise to the formation of the molecules respectively of chloric and of perchloric acids.

We are thus enabled, by availing ourselves exclusively of oxygen as building material, to convert the two-storied molecule of hydrochloric acid successively into a three, four-, five-storied molecule, and ultimately even into the six-storied molecule of perchloric acid; and there is no reason why a happy experimentalist, by using additional and more complicated scaffolding, should not succeed in raising still loftier structures. FIG. 11.

At this stage we may appropriately resume the question suggested by the earlier considerations of this evening. The facility with which our newly-acquired building

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The reason why, when uniting with a compound, oxygen joins this compound, atom by atom, is now obvious. By opening a finished molecule, two attraction units are set free; these may be balanced by one atom of oxygen, but also by a chain of two, three, four,—in fact, of any number of oxygen atoms. Of the two, four, six, eight, &c. attraction units possessed by one, two, three, and four atoms of oxygen, two, four, and six units are consumed in linking these atoms into a chain, so that only two units-one at each end of the chain-remain at our disposal, and may be used in closing up again the broken molecule.

Not less satisfactory is the information supplied by the consideration of a series of nitrogenetted compounds. In hydride of ethyl we possess a molecule containing two atoms of carbon and six atoms of hydrogen. With the view of introducing an atom of nitrogen, we break this molecule. A glance at our model (Fig. 12) shows us at once that, by inserting between the fragments a nitrogen atom only, three attraction units with which the nitrogen atom enters, we are unable to reproduce a finished building, for of the two only are saturated; one remains unsaturated; indeed, one nitrogen arm projects uncovered. It is only by addition

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of another atom of hydrogen that the closed molecule of ethylamine is formed. This molecule again we open, again we introduce an atom of nitrogen, and again we observe that one attraction unit of the newly-added atom remains unsatisfied, and that an additional atom of hydrogen is required for the transformation of ethylamine into ethylenediamine, and so again when ethylene-diamine is to be converted into vinyltriamine (Figs. 13 and 14).

the atom of oxygen, but always carries an atom of hydroWhy the nitrogen atom does not combine directly, like gen along with it, is now likewise demonstrated. If a finished molecule be broken for the reception of a new atom, the number of combining units liberated is always two. This, as we have seen, is the number which is saturated by one atom of oxygen, or by a chain of oxygen by a nitrogen atom, one of the attraction units of the atoms; but when these two attraction units are saturated free must be equal to the number of atoms composing the nitrogen remains free; when they are saturated by a chain of nitrogen atoms, the number of attraction units remaining nitrogen chain.

NEWS

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ACADEMY OF SCIENCES.
October 2.

THE only chemical paper read was by M. E. Kopp, " On
the Utilisation of Soda Waste, and the Residues of the
Manufacture of Chlorine." All the ideas in this paper are
old, and most of them will be found in Dr. Hotmann's
Exhibition Report, pp. 32-33:
The author's present
method of proceeding is as follows:-He takes the acid
residual liquor obtained in the manufacture of chloride of
lime, allows the solid matters to deposit, and then adds
just enough soda waste to destroy the free chlorine and
convert the per- and sesqui-chlorides of iron and man-
ganese into protochlorides. Some sulphur is separated,
which may be collected, and some sulphuretted hydrogen
is evolved, which may be absorbed by ferric oxide. The
dechlorinated, but still acid liquor is now pumped into a
special apparatus, in which it is completely saturated with
soda waste. A large amount of sulphuretted hydrogen is
then evolved, and may be burned so as to produce either
water and sulphur, or water and sulphurous acid. The
author gives another process for the utilisation of soda
waste. When the waste is exposed to the air, M. Kopp
has found that the oxy-sulphide of calcium (2 CaS,CaO)
changes into bisulphide of calcium and quicklime. By
further oxidation the bisulphide is transformed into calcic
hyposulphite, which, on drying, becomes converted into
calcic sulphite and free sulphur. The calcic sulphite is
soon further oxidised to sulphate, while the free sulphur
unites with a fresh quantity of sulphide to form soluble
bisulphides or even polysulphides. The sulphide of cal-
cium always present in the waste undergoes similar
changes. When water falls on the heaps, a deep yellow
or orange coloured solution is formed, which contains
these polysulphides of calcium, with some hyposulphite of
soda and lime. On leaving this liquor exposed to the air
in thin layers during the summer months, oxidation takes
place, and hyposulphites and free sulphur are obtained.
Or it may be treated with sulphurous acid with the same
object; or, lastly, neutral solutions of chloride of man-
ganese or iron may be added, and thus a mixed precipitate
procured of sulphides and sulphur, which may be burned
to furnish sulphuric acid. All this, we believe, has
already been done by Messrs. Townsend and Walker.
Some discussion followed the reading of this paper, in
which M. Pelouze mentioned a process of M. Schaffner,
who decomposes the yellow solution obtained after the
exposure of the waste with dilute hydrochloric acid or
chlorine residues, and thus recovers a portion of the sulphur.
M. Dumas afterwards pointed out the principal features
of M. Kopp's processes.

M. H. St. Claire Deville communicated a note from M. Fongué, describing his visits to Stromboli, Vulcano, and Panaria, and giving analyses of gases from fumaroles on those volcanic islands. Around some of the fumaroles he found deposits of sulphide of arsenic, chloride of iron, sal ammonia, sulphur, and boracic acid, and the gases were, in a few instances, principally composed of sulphurous and chlorhydric acids.

The Academy seems deluged with communications on the subject of cholera. Many of these dwell on the almost universal occurrence of premonitory diarrhoea, and the importance of immediate treatment.

To Blacken Zinc Statues, &c.-Make a solution of six parts chloride of antimony in one part of alcohol and four parts hydrochloric acid, and apply it to the object with a brush. Wipe the figure over with a wet cloth. and then apply the solution a second time. Now dry the object as quickly as possible in a warm place. When it is perfectly dry rub it all over with oil.-Deutch. Illust. Gewerbztg, 1864.

NEW

NOTICES OF BOOKS.

A Practical Treatise on Coal, Petroleum, and other Distilled Oils. By ABRAHAM GESNER, M.D., F.G.S. Second edition. Revised and enlarged, by GEORGE WELDTEN GESNER, Consulting Chemist and Engineer. London: H. Baillière. 1865.

ALTHOUGH it is impossible to give unqualified praise to any part of this book, we are bound to say that it is one which, in the present dearth of practical works on the subject deserves some commendation. It seems strange that so important an industry has not produced more books, but the reason for this, we imagine, is to be found in the fact that the manufacture of coal oils has been so much embarrassed by the operation of our patent laws, that few have hitherto cared to engage in the pursuit. However that may have been, we have noticed that a larger number of inquiries have been addressed to us for information on this subject than on any other, and we may now content ourselves with recommending this book to the perusal of all who wish for practical information on the subject of which it treats.

Our readers will understand from the above that it is the practical part of the book alone which we commend. The chemistry is, indeed, of a kind which had better been omitted, and which if the book should reach a third edition must undergo a thorough revision by a competent chemist.

It is proper to add that the book is illustrated with drawings of ovens, retorts, stills, and other necessary apparatus, which will be found extremely useful as guides to those who think of embarking in the manufacture of coal and shale oils.

In this number we find the completion of the article by Annales de Physique et de Chimie. August, 1865. Dr. Icery "On the Juice of the Sugar Cane, and the Changes it undergoes in the Manufacture of Sugar." It is a most valuable contribution to our knowledge of the natural history of sugar, and well deserves the attention of all engaged in the manufacture. A fourth memoir by M. A. Dupré, "On the Mechanical Theory of Heat," and devoted to the study of latent heats, is the only other article which has not already received notice in our pages. In this number the valuable review of foreign (that is, other than French) memoirs of M. Wurtz is resumed; but in this we find nothing for notice.

Zeitschrift für Analytische Chemie. Part 1. Vol. IV. THIS journal opens with an article by Dr. Gerlach "On Areometer Scales," which is accompanied by a very useful table for the comparison of Twaddle's with Beaume's and other scales, and also with the specific gravity. The author has compiled it for liquids both heavier and lighter Volumetric Determination of Alumina and Phosphoric Acid." than water. The next is an article by E. Fleischer "On the

The author estimates the one with a standard solution of

potash alum, and the other with a standard solution of phosphate of soda. Our readers will see that these processes can have but a very limited application. W. Casselman, in a paper "On a Remarkable Formation of a Basic Salt of Cupric Acid," describes salt having the general formula 2 (4CuO + Acid) 7HO, which is made by boiling the solution of a copper salt with a salt of formic, acetic, propionic, or valerianic acid. Dr. Piccard describes a rather injurious "Way of Hastening Filtrations." He fits the funnel with a filter into one neck of a two-necked Wolff's bottle. From the other he carries a tube which he connects with a water aspirator. Some atmospheric pressure is thereby maintained on the fluid in the filter, and the filtration consequently accelerated. Some remarks by

News,

Fausto Sestini "On the Preparation of Pure Lime for Use in the Elementary Analysis of Organic Substances," do not call for much notice. The author impregnates the purest statuary marble with a thick syrup, and then burns it When the lime is causticised, he makes thin milk of lime, in which any carbonaceous matter deposits. He then collects the lime on a filter, and washes well to remove any sulphide of calcium which may have been formed from sulphate in the marble. He then dissolves the lime in nitric acid, precipitates with carbonate of ammonia, and again burns the carbonate into quick lime. He thus obtains lime quite free from chlorine and sulphuric acid, and so adapted for use in the analysis of organic bodies containing chlorine.

Among the communications from Fresenius's laboratory we notice a paper by F. Gauhe "On the Methods of Estimating Cobalt and Nickel; another by A. Souchay," On the Estimation of Lead as Sulphide;" and one by the same author" On the Determination of Chromium as Hydrated Oxide, and Weighing as Oxide." In the last paper the author points out a common error in the solution of the glass in which the precipitation and washing is effected, and recommends the use of a porcelain or platinum dish. The next is an article by Fresenius" On the Analysis of Raw Iron," to which we shall return.

In another short paper Fresenius gives a small hint for the laboratory. Every one knows that the iron-wire gauze on which we heat beakers over a gas flame burns out in the middle, and soon becomes useless. Fresenius suggests taking a thin, square plate of iron for the beaker to rest upon, and fastening it to the gauze by the corners. This, he says, will form a very safe rest for the beaker, and will hold a long time.

The remaining articles call for no notice.

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2296. J. Dawson, Greenock, Renfrewshire, N.B., "Improvements in supplying charcoal to sugar decolourising vessels, and in apparatus therefor."-September 7, 1865.

2327. J. Lightfoot, Accrington, Lancashire, "Improvements in dyeing and printing fabrics and yarns and animal or mixed animal and vegetable substances."-September 11, 1865.

2385. J. Fletcher, Betts Street, St. George's-in-theEast, Middlesex, "Improvements in the machinery or apparatus and in the processes for the treatment and manufacture of sugar."

2390. J. S. McDougall, Manchester, "Improvements in the manufacture of insoluble oils and greases."-September 19, 1865.

2409. W. Clark, Chancery Lane, "Improvements in the manufacture of materials for decolourising sugars and other saccharine and liquid matters." A communication from C. J. Gaade, Boulevart St. Martin, Paris.

2415. A. Bird, Birmingham, “Improvements in purifying water."-September 21, 1865.

2427. P. Spence, Newton Heath, Manchester, "Improvements in the manufacture of white lead."-September 22, 1865.

2435. J. H. Johnson, Lincoln's Inn Fields, Middlesex, Improvements in generating illuminating gas, and in the machinery or apparatus employed therein." A com

munication from E. A. Pond, M. S. Richardson, and E. A. Morse, Rutland, Vermont, U.S.A.

2439. A. V. Newton, Chancery Lane, "Improved apparatus for generating illuminating gas." A communication from J. Irwin, Chicago, Illinois, U.S.A.

2443. M. Schaffner, Aussig, Bohemia, "Improvements in treating soda waste to obtain sulphur therefrom."— Sept. 23, 1865.

2451. E. Brooke, the younger, Huddersfield, "An improved arrangement of apparatus and materials to be employed for effecting the deodorising of the noxious gases arising from sewers and drains, and for the more effectual ventilation and inspection of such sewers and drains."-Sept. 25, 1865.

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2469. G. T. Bousfield, Loughborough Park, Brixton, Improvements in machinery for tempering and preparing peat for fuel." A communication from N. F. Potter, Providence, Rhode Island, U.S.A.-Sept. 26, 1865. NOTICES TO PROCEED.

1352. W. Wright, Mostyn, Flintshire, "Improvements in the treatment of the waste liquors obtained after treating burnt ores of copper, such improvements having for their object the production or extraction of cobalt and nickel."

1461. G. Walton, Weardale Villa, Clapton, "Improvements in apparatus used in distilling hydrocarbons."May 16, 1865.

1385. T. Richardson, Newcastle-upon-Tyne, and M. D. Rücker, Leadenhall Street, London, "Improvements in obtaining certain compounds of nitrogen and of sulphur." May 19, 1865.

1435. J. Gyers, Middlesborough, "Improvements in ovens or kilns for the manufacture of coke."-May 25, 1865.

1545. C. H. Wansbrough, Shrewton, Wiltshire, "Improvements in the treatment of condensing pans employed in the condensation of milk."-A communication from S. Percy, New York, U.S.A.-June 5, 1865.

1553 J. Howarth, M.D., Andover, Essex, Mass, U.S.A., "An improved method and apparatus for distilling coal, shale, and other carbonaceous substances."-A communication from J. Howarth, Salem, U.S.A.-June 7, 1865. 2289. T. Nicholson, Gateshead, "An improved process of and apparatus for making caustic liquor or caustic lees."-September 6, 1865.

1420. J. Dale and A. Paraf, Manchester, "Improvements in calico and linen printing."-May 24, 1865.

1448. R. Canham, Clerkenwell, Middlesex, "Improvements in cupola and other blast furnaces."

1450. C. B. Spaeth, Philpot Lane, London, "A new preparation for subduing and extinguishing fire." A communication from G. Zeisler, Leipsig, Saxony.-May 26, 1865.

1453. S. Sequelin, Devonshire Street, Bloomsbury, "Improvements in purifying animal and vegetable oils or fatty matters to be used for lubricating and other purposes."-May 27, 1865.

1489. T. Spencer, Euston Square, Middlesex, "Improvements in the composition and manufacture of paints applicable to iron and other ships' bottoms, and for other general purposes.' -May 31, 1865.

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2153. G. G. Dennis, Boston, Mass., U.S.A., "Improvements in friction matches, lucifer matches, and matches for re-lighting called taper matches."—August 21, 1865.

MISCELLANEOUS.

Ozone.-At the meeting of the British Association, Dr. B. W. Richardson read a paper on certain physiological experiments with ozone. The following are the reliable facts known up to this time respecting ozone:

1. Ozone in a natural state is always present in the air in minute proportions—viz., one part in ten thousand.

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